47 results on '"Lakhssassi N"'
Search Results
2. Absence of Helicobacter pylori in the oral cavity of 10 non-dyspeptic subjects demonstrated by real-time polymerase chain reaction
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Martinez-Gomis, J., Diouf, A., Lakhssassi, N., and Sixou, M.
- Published
- 2006
3. Carpegen® real-time polymerase chain reaction vs. anaerobic culture for periodontal pathogen identification
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Verner, C., Lemaitre, P., Daniel, A., Giumelli, B., Lakhssassi, N., and Sixou, M.
- Published
- 2006
4. Antimicrobial susceptibility variation of 50 anaerobic periopathogens in aggressive periodontitis: an interindividual variability study
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Lakhssassi, N., Elhajoui, N., Lodter, J.-P., Pineill, J.-L., and Sixou, M.
- Published
- 2005
5. Prothèse amovible complète retenue par un implant symphysaire médian
- Author
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Abdelkoui, A., primary, Lakhssassi, N., additional, Merzouk, N., additional, and Berrada, S., additional
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- 2017
- Full Text
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6. L’expansion osseuse atraumatique : intérêts de la combinaison pièzo-chirurgie, expanseurs coniques et implantation immédiate
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Iraqui, O., primary, Lakhssassi, N., additional, Berrada, S., additional, and Merzouk, N., additional
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- 2016
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7. Dégradation de l'ADN bactérien par de l'azote atomique produit par plasma. Apport de la détection par PCR en temps réel
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Lakhssassi, N., primary, Cousty, S., additional, Villeger, S., additional, Diouf, A., additional, Ricard, A., additional, and Sixou, M., additional
- Published
- 2006
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8. Variabilité de l'efficacité de l'érythromycine et de la spiramycine sur les pathogènes parodontaux dans les parodontites agressives. Étude in vitro comparative
- Author
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Lakhssassi, N., primary and Sixou, M., additional
- Published
- 2005
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9. A sucrose-binding protein and β-conglycinins regulate soybean seed protein content and control multiple seed traits.
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Lakhssassi N, El Baze A, Knizia D, Salhi Y, Embaby MG, Anil E, Mallory C, Lakhssassi A, Meksem J, Shi H, Vuong TD, Meksem K, Kassem MA, AbuGhazaleh A, Nguyen HT, Bellaloui N, Boualem A, and Meksem K
- Subjects
- Mutation genetics, Grain Proteins metabolism, Amino Acids metabolism, Plant Proteins genetics, Plant Proteins metabolism, Sucrose metabolism, Gene Expression Regulation, Plant, Seeds genetics, Seeds metabolism, Seed Storage Proteins genetics, Seed Storage Proteins metabolism, Glycine max genetics, Glycine max metabolism, Globulins genetics, Globulins metabolism, Soybean Proteins genetics, Soybean Proteins metabolism, Antigens, Plant genetics, Antigens, Plant metabolism
- Abstract
Expanded agriculture production is required to support the world's population but can impose substantial environmental and climate change costs, particularly with intensifying animal production and protein demand. Shifting from an animal- to a plant-based protein diet has numerous health benefits. Soybean (Glycine max [L.] Merr.) is a major source of protein for human food and animal feed; improved soybean protein content and amino acid composition could provide high-quality soymeal for animal feed, healthier human foods, and a reduced carbon footprint. Nonetheless, during the soybean genome evolution, a balance was established between the amount of seed protein, oil, and carbohydrate content, burdening the development of soybean cultivars with high proteins (HPs). We isolated 2 high-seed protein soybean mutants, HP1 and HP2, with improved seed amino acid composition and stachyose content, pointing to their involvement in controlling seed rebalancing phenomenon. HP1 encodes β-conglycinin (GmCG-1) and HP2 encodes sucrose-binding protein (GmSBP-1), which are both highly expressed in soybean seeds. Mutations in GmSBP-1, GmCG-1, and the paralog GmCG-2 resulted in increased protein levels, confirming their role as general regulators of seed protein content, amino acid seed composition, and seed vigor. Biodiversity analysis of GmCG and GmSBP across 108 soybean accessions revealed haplotypes correlated with protein and seed carbohydrate content. Furthermore, our data revealed an unprecedented role of GmCG and GmSBP proteins in improving seed vigor, crude protein, and amino acid digestibility. Since GmSBP and GmCG are present in most seed plants analyzed, these genes could be targeted to improve multiple seed traits., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
- Published
- 2024
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10. Potential of Sorghum Seeds in Alleviating Hyperglycemia, Oxidative Stress, and Glycation Damage.
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Ben El Mahdi N, Lemée L, Remaury QB, Eloy L, Nhiri N, Lakhssassi N, Cacciola F, and Nhiri M
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- Animals, Mice, Hyperglycemia drug therapy, Hyperglycemia metabolism, Diabetes Mellitus, Experimental drug therapy, Diabetes Mellitus, Experimental metabolism, Glycation End Products, Advanced metabolism, Flavonoids pharmacology, Male, Glycosylation drug effects, Sorghum chemistry, Oxidative Stress drug effects, Seeds chemistry, Plant Extracts pharmacology, Plant Extracts chemistry, Antioxidants pharmacology
- Abstract
Diabetes mellitus, characterized by dysregulated glucose metabolism, oxidative stress, and the formation of advanced glycation end products, poses a significant global health burden. In this study, we explored the potential of sorghum ( Sorghum bicolor ) seeds, known for their abundant phytochemical composition, as a natural remedy for diabetes and its associated damage. High-performance liquid chromatography/high-resolution mass spectrometry analysis revealed a remarkable phenolic richness in sorghum grains, including gallic acid, quercetin, and the predominant procyanidin B-1, with ecotype-specific variations in flavonoid distribution. Elemental analysis by ICP showed an abundance of macro-elements (Ca, K, Mg), trace elements (Fe, Mn, Si, Zn), and ultra-trace elements (B, Co, Cr, Cu, Mo, Se, V) essential for human health, supporting its therapeutic and nutritional potential. Additionally, the results demonstrated variable total phenolic contents (188-297 mg GAE/g dE) and total flavonoid contents (66-78 mg QE/g dE), with corresponding differences in antioxidant activities across the five ecotypes. Treatment with sorghum seed extract (SE1) significantly reduced oxidative stress markers, such as malondialdehyde (MDA)by 40% and hydrogen peroxide (H
2 O2 ) by 63%, in diabetic mice, compared to untreated diabetic controls. Moreover, sorghum extracts exhibited a remarkable increase in antioxidant enzyme activities, including a 50% increase in superoxide dismutase (SOD) activity and a 60% increase in glutathione peroxidase (GPx) activity, indicating their potential to bolster antioxidant defenses against diabetes-induced oxidative stress. These findings underscore the therapeutic potential of sorghum seeds in diabetes management and prevention, paving the way for the development of functional foods with enhanced health benefits.- Published
- 2024
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11. Deep Learning Model for Classifying and Evaluating Soybean Leaf Disease Damage.
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Goshika S, Meksem K, Ahmed KR, and Lakhssassi N
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- Animals, Humans, Glycine max, Animal Feed, Plant Leaves, Deep Learning, Pesticides
- Abstract
Soybean ( Glycine max (L.) Merr.) is a major source of oil and protein for human food and animal feed; however, soybean crops face diverse factors causing damage, including pathogen infections, environmental shifts, poor fertilization, and incorrect pesticide use, leading to reduced yields. Identifying the level of leaf damage aids yield projections, pesticide, and fertilizer decisions. Deep learning models (DLMs) and neural networks mastering tasks from abundant data have been used for binary healthy/unhealthy leaf classification. However, no DLM predicts and categorizes soybean leaf damage severity (five levels) for tailored pesticide use and yield forecasts. This paper introduces a novel DLM for accurate damage prediction and classification, trained on 2930 near-field soybean leaf images. The model quantifies damage severity, distinguishing healthy/unhealthy leaves and offering a comprehensive solution. Performance metrics include accuracy, precision, recall, and F1-score. This research presents a robust DLM for soybean damage assessment, supporting informed agricultural decisions based on specific damage levels and enhancing crop management and productivity.
- Published
- 2023
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12. Genetic Mapping for QTL Associated with Seed Nickel and Molybdenum Accumulation in the Soybean 'Forrest' by 'Williams 82' RIL Population.
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Bellaloui N, Knizia D, Yuan J, Song Q, Betts F, Register T, Williams E, Lakhssassi N, Mazouz H, Nguyen HT, Meksem K, Mengistu A, and Kassem MA
- Abstract
Understanding the genetic basis of seed Ni and Mo is essential. Since soybean is a major crop in the world and a major source for nutrients, including Ni and Mo, the objective of the current research was to map genetic regions (quantitative trait loci, QTL) linked to Ni and Mo concentrations in soybean seed. A recombinant inbred line (RIL) population was derived from a cross between 'Forrest' and 'Williams 82' (F × W82). A total of 306 lines was used for genotyping using 5405 single nucleotides polymorphism (SNP) markers using Infinium SNP6K BeadChips. A two-year experiment was conducted and included the parents and the RIL population. One experiment was conducted in 2018 in North Carolina (NC), and the second experiment was conducted in Illinois in 2020 (IL). Logarithm of the odds (LOD) of ≥2.5 was set as a threshold to report identified QTL using the composite interval mapping (CIM) method. A wide range of Ni and Mo concentrations among RILs was observed. A total of four QTL ( qNi-01 , qNi-02 , and qNi-03 on Chr 2, 8, and 9, respectively, in 2018, and qNi-01 on Chr 20 in 2020) was identified for seed Ni. All these QTL were significantly (LOD threshold > 2.5) associated with seed Ni, with LOD scores ranging between 2.71-3.44, and with phenotypic variance ranging from 4.48-6.97%. A total of three QTL for Mo ( qMo-01 , qMo-02 , and qMo-03 on Chr 1, 3, 17, respectively) was identified in 2018, and four QTL ( qMo-01 , qMo-02 , qMo-03 , and qMo-04 , on Chr 5, 11, 14, and 16, respectively) were identified in 2020. Some of the current QTL had high LOD and significantly contributed to the phenotypic variance for the trait. For example, in 2018, Mo QTL qMo-01 on Chr 1 had LOD of 7.8, explaining a phenotypic variance of 41.17%, and qMo-03 on Chr 17 had LOD of 5.33, with phenotypic variance explained of 41.49%. In addition, one Mo QTL ( qMo-03 on Chr 14) had LOD of 9.77, explaining 51.57% of phenotypic variance related to the trait, and another Mo QTL ( qMo-04 on Chr 16) had LOD of 7.62 and explained 49.95% of phenotypic variance. None of the QTL identified here were identified twice across locations/years. Based on a search of the available literature and of SoyBase, the four QTL for Ni, identified on Chr 2, 8, 9, and 20, and the five QTL associated with Mo, identified on Chr 1, 17, 11, 14, and 16, are novel and not previously reported. This research contributes new insights into the genetic mapping of Ni and Mo, and provides valuable QTL and molecular markers that can potentially assist in selecting Ni and Mo levels in soybean seeds.
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- 2023
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13. Soybean gene co-expression network analysis identifies two co-regulated gene modules associated with nodule formation and development.
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Piya S, Pantalone V, Zadegan SB, Shipp S, Lakhssassi N, Knizia D, Krishnan HB, Meksem K, and Hewezi T
- Subjects
- Gene Expression Regulation, Plant genetics, Gene Expression Profiling, Transcription Factors genetics, Glycine max genetics, Gene Regulatory Networks
- Abstract
Gene co-expression network analysis is an efficient systems biology approach for the discovery of novel gene functions and trait-associated gene modules. To identify clusters of functionally related genes involved in soybean nodule formation and development, we performed a weighted gene co-expression network analysis. Two nodule-specific modules (NSM-1 and NSM-2, containing 304 and 203 genes, respectively) were identified. The NSM-1 gene promoters were significantly enriched in cis-binding elements for ERF, MYB, and C2H2-type zinc transcription factors, whereas NSM-2 gene promoters were enriched in cis-binding elements for TCP, bZIP, and bHLH transcription factors, suggesting a role of these regulatory factors in the transcriptional activation of nodule co-expressed genes. The co-expressed gene modules included genes with potential novel roles in nodulation, including those involved in xylem development, transmembrane transport, the ethylene signalling pathway, cytoskeleton organization, cytokinesis and regulation of the cell cycle, regulation of meristem initiation and growth, transcriptional regulation, DNA methylation, and histone modifications. Functional analysis of two co-expressed genes using TILLING mutants provided novel insight into the involvement of unsaturated fatty acid biosynthesis and folate metabolism in nodule formation and development. The identified gene co-expression modules provide valuable resources for further functional genomics studies to dissect the genetic basis of nodule formation and development in soybean., (© 2023 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)
- Published
- 2023
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14. Proteomic, Transcriptomic, Mutational, and Functional Assays Reveal the Involvement of Both THF and PLP Sites at the GmSHMT08 in Resistance to Soybean Cyst Nematode.
- Author
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Lakhssassi N, Knizia D, El Baze A, Lakhssassi A, Meksem J, and Meksem K
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- Animals, Carbon, Glycine metabolism, Glycine Hydroxymethyltransferase chemistry, Glyoxylates, Heme, Methionine genetics, Plant Diseases genetics, Proteomics, Purines, Pyridoxal Phosphate metabolism, Serine genetics, Glycine max metabolism, Tetrahydrofolates genetics, Tetrahydrofolates metabolism, Transcriptome, Cysts, Nematoda genetics
- Abstract
The serine hydroxymethyltransferase (SHMT; E.C. 2.1.2.1) is involved in the interconversion of serine/glycine and tetrahydrofolate (THF)/5,10-methylene THF, playing a key role in one-carbon metabolism, the de novo purine pathway, cellular methylation reactions, redox homeostasis maintenance, and methionine and thymidylate synthesis. GmSHMT08 is the soybean gene underlying soybean cyst nematode (SCN) resistance at the Rhg4 locus. GmSHMT08 protein contains four tetrahydrofolate (THF) cofactor binding sites (L129, L135, F284, N374) and six pyridoxal phosphate (PLP) cofactor binding/catalysis sites (Y59, G106, G107, H134, S190A, H218). In the current study, proteomic analysis of a data set of protein complex immunoprecipitated using GmSHMT08 antibodies under SCN infected soybean roots reveals the presence of enriched pathways that mainly use glycine/serine as a substrate (glyoxylate cycle, redox homeostasis, glycolysis, and heme biosynthesis). Root and leaf transcriptomic analysis of differentially expressed genes under SCN infection supported the proteomic data, pointing directly to the involvement of the interconversion reaction carried out by the serine hydroxymethyltransferase enzyme. Direct site mutagenesis revealed that all mutated THF and PLP sites at the GmSHMT08 resulted in increased SCN resistance. We have shown the involvement of PLP sites in SCN resistance. Specially, the effect of the two Y59 and S190 PLP sites was more drastic than the tested THF sites. This unprecedented finding will help us to identify the biological outcomes of THF and PLP residues at the GmSHMT08 and to understand SCN resistance mechanisms.
- Published
- 2022
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15. QTL and Candidate Genes for Seed Tocopherol Content in 'Forrest' by 'Williams 82' Recombinant Inbred Line (RIL) Population of Soybean.
- Author
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Knizia D, Yuan J, Lakhssassi N, El Baze A, Cullen M, Vuong T, Mazouz H, T Nguyen H, Kassem MA, and Meksem K
- Abstract
Soybean seeds are rich in secondary metabolites which are beneficial for human health, including tocopherols. Tocopherols play an important role in human and animal nutrition thanks to their antioxidant activity. In this study, the 'Forrest' by 'Williams 82' (F×W82) recombinant inbred line (RIL) population ( n = 306) was used to map quantitative trait loci (QTL) for seed α-tocopherol, β-tocopherol, δ -tocopherol, γ-tocopherol, and total tocopherol contents in Carbondale, IL over two years. Also, the identification of the candidate genes involved in soybean tocopherols biosynthetic pathway was performed. A total of 32 QTL controlling various seed tocopherol contents have been identified and mapped on Chrs. 1, 2, 5, 6, 7, 8, 9, 10, 12, 13, 16, 17, and 20. One major and novel QTL was identified on Chr. 6 with an R
2 of 27.8, 9.9, and 6.9 for δ-tocopherol, α-tocopherol, and total tocopherol content, respectively. Reverse BLAST analysis of the genes that were identified in Arabidopsis allowed the identification of 37 genes involved in soybean tocopherol pathway, among which 11 were located close to the identified QTLs. The tocopherol cyclase gene ( TC ) Glyma.06G084100 is located close to the QTLs controlling δ-tocopherol (R2 = 27.8), α-tocopherol (R2 = 9.96), and total-tocopherol (R2 = 6.95). The geranylgeranyl diphosphate reductase ( GGDR ) Glyma.05G026200 gene is located close to a QTL controlling total tocopherol content in soybean (R2 = 4.42). The two methylphytylbenzoquinol methyltransferase ( MPBQ-MT ) candidate genes Glyma.02G002000 and Glyma.02G143700 are located close to a QTL controlling δ-tocopherol content (R2 = 3.57). The two γ-tocopherol methyltransferase ( γ-TMT ) genes, Glyma.12G014200 and Glyma.12G014300 , are located close to QTLs controlling (γ+ß) tocopherol content (R2 = 8.86) and total tocopherol (R2 = 5.94). The identified tocopherol seed QTLs and candidate genes will be beneficial in breeding programs to develop soybean cultivars with high tocopherol contents.- Published
- 2022
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16. Genome-wide identification and analysis of soybean acyl-ACP thioesterase gene family reveals the role of GmFAT to improve fatty acid composition in soybean seed.
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Zhou Z, Lakhssassi N, Knizia D, Cullen MA, El Baz A, Embaby MG, Liu S, Badad O, Vuong TD, AbuGhazaleh A, Nguyen HT, and Meksem K
- Subjects
- Multigene Family, Oleic Acid, Palmitic Acid, Phylogeny, Plant Breeding, Seeds chemistry, Glycine max enzymology, Fatty Acids chemistry, Plant Proteins genetics, Soybean Oil chemistry, Glycine max genetics, Thiolester Hydrolases genetics
- Abstract
Key Message: Soybean acyl-ACP thioesterase gene family have been characterized; GmFATA1A mutants were discovered to confer high oleic acid, while GmFATB mutants presented low palmitic and high oleic acid seed content. Soybean oil stability and quality are primarily determined by the relative proportions of saturated versus unsaturated fatty acids. Commodity soybean typically contains 11% palmitic acid, as the primary saturated fatty acids. Reducing palmitic acid content is the principal approach to minimize the levels of saturated fatty acids in soybean. Though high palmitic acid enhances oxidative stability of soybean oil, it is negatively correlated with oil and oleic acid content and can cause coronary heart diseases for humans. For plants, acyl-acyl carrier protein (ACP) thioesterases (TEs) are a group of enzymes to hydrolyze acyl group and release free fatty acid from plastid. Among them, GmFATB1A has become the main target to genetically reduce the palmitic acid content in soybean. However, the role of members in soybean acyl-ACP thioesterase gene family is largely unknown. In this study, we characterized two classes of TEs, GmFATA, and GmFATB in soybean. We also denominated two GmFATA members and discovered six additional members that belong to GmFATB gene family through phylogenetic, syntenic, and in silico analysis. Using TILLING-by-Sequencing
+ , we identified an allelic series of mutations in five soybean acyl-ACP thioesterase genes, including GmFATA1A, GmFATB1A, GmFATB1B, GmFATB2A, and GmFATB2B. Additionally, we discovered mutations at GmFATA1A to confer high oleic acid (up to 34.5%) content, while mutations at GmFATB presented low palmitic acid (as low as 5.6%) and high oleic acid (up to 36.5%) phenotypes. The obtained soybean mutants with altered fatty acid content can be used in soybean breeding program for improving soybean oil composition traits., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2021
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17. The Soybean High Density 'Forrest' by 'Williams 82' SNP-Based Genetic Linkage Map Identifies QTL and Candidate Genes for Seed Isoflavone Content.
- Author
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Knizia D, Yuan J, Bellaloui N, Vuong T, Usovsky M, Song Q, Betts F, Register T, Williams E, Lakhssassi N, Mazouz H, Nguyen HT, Meksem K, Mengistu A, and Kassem MA
- Abstract
Isoflavones are secondary metabolites that are abundant in soybean and other legume seeds providing health and nutrition benefits for both humans and animals. The objectives of this study were to construct a single nucleotide polymorphism (SNP)-based genetic linkage map using the 'Forrest' by 'Williams 82' (F×W82) recombinant inbred line (RIL) population ( n = 306); map quantitative trait loci (QTL) for seed daidzein, genistein, glycitein, and total isoflavone contents in two environments over two years (NC-2018 and IL-2020); identify candidate genes for seed isoflavone. The FXW82 SNP-based map was composed of 2075 SNPs and covered 4029.9 cM. A total of 27 QTL that control various seed isoflavone traits have been identified and mapped on chromosomes (Chrs.) 2, 4, 5, 6, 10, 12, 15, 19, and 20 in both NC-2018 (13 QTL) and IL-2020 (14 QTL). The six QTL regions on Chrs. 2, 4, 5, 12, 15, and 19 are novel regions while the other 21 QTL have been identified by other studies using different biparental mapping populations or genome-wide association studies (GWAS). A total of 130 candidate genes involved in isoflavone biosynthetic pathways have been identified on all 20 Chrs. And among them 16 have been identified and located within or close to the QTL identified in this study. Moreover, transcripts from four genes ( Glyma.10G058200 , Glyma.06G143000 , Glyma.06G137100 , and Glyma.06G137300 ) were highly abundant in Forrest and Williams 82 seeds. The identified QTL and four candidate genes will be useful in breeding programs to develop soybean cultivars with high beneficial isoflavone contents.
- Published
- 2021
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18. Genome Wide MeDIP-Seq Profiling of Wild and Cultivated Olives Trees Suggests DNA Methylation Fingerprint on the Sensory Quality of Olive Oil.
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Badad O, Lakhssassi N, Zaid N, El Baze A, Zaid Y, Meksem J, Lightfoot DA, Tombuloglu H, Zaid EH, Unver T, and Meksem K
- Abstract
Secondary metabolites are particularly important to humans due to their pharmaceutical properties. Moreover, secondary metabolites are key compounds in climate change adaptation in long-living trees. Recently, it has been described that the domestication of Olea subspecies had no major selection signature on coding variants and was mainly related to changes in gene expression. In addition, the phenotypic plasticity in Olea subspecies was linked to the activation of transposable elements in the genes neighboring. Here, we investigated the imprint of DNA methylation in the unassigned fraction of the phenotypic plasticity of the Olea subspecies, using methylated DNA immuno-precipitation sequencing (MeDIP-seq) for a high-resolution genome-wide DNA methylation profiling of leaves and fruits during fruit development in wild and cultivated olives from Turkey. Notably, the methylation profiling showed a differential DNA methylation in secondary metabolism responsible for the sensory quality of olive oil. Here, we highlight for the first time the imprint of DNA methylation in modulating the activity of the Linoleate 9S lipoxygenase in the biosynthesis of volatile aromatic compounds. Unprecedently, the current study reveals the methylation status of the olive genome during fruit ripening.
- Published
- 2021
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19. Dissecting nematode resistance regions in soybean revealed pleiotropic effect of soybean cyst and reniform nematode resistance genes.
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Usovsky M, Lakhssassi N, Patil GB, Vuong TD, Piya S, Hewezi T, Robbins RT, Stupar RM, Meksem K, and Nguyen HT
- Subjects
- Animals, DNA Copy Number Variations, Disease Resistance genetics, Plant Diseases genetics, Glycine max genetics, Cysts, Tylenchoidea
- Abstract
Reniform nematode (RN, Rotylenchulus reniformis Linford & Oliveira) has emerged as one of the most important plant parasitic nematodes of soybean [Glycine max (L.) Merr.]. Planting resistant varieties is the most effective strategy for nematode management. The objective of this study was to identify quantitative trait loci (QTL) for RN resistance in an exotic soybean line, PI 438489B, using two linkage maps constructed from the Universal Soybean Linkage Panel (USLP 1.0) and next-generation whole-genome resequencing (WGRS) technology. Two QTL controlling RN resistance were identified-the soybean cyst nematode (SCN, Heterodera glycines) resistance gene GmSNAP18 at the rhg1 locus and its paralog GmSNAP11. Strong association between resistant phenotype and haplotypes of the GmSNAP11 and GmSNAP18 was observed. The results indicated that GmSNAP11 possibly could have epistatic effect on GmSNAP18, or vice versa, with the presence of a significant correlation in RN resistance of rhg1-a GmSNAP18 vs. rhg1-b GmSNAP18. Most importantly, our preliminary data suggested that GmSNAP18 and GmSNAP11 proteins physically interact in planta, suggesting that they belong to the same pathway for resistance. Unlike GmSNAP18, no indication of GmSNAP11 copy number variation was found. Moreover, gene-based single nucleotide polymorphism (SNP) markers were developed for rapid detection of RN or SCN resistance at these loci. Our analysis substantiates synergic interaction between GmSNAP11 and GmSNAP18 genes and confirms their roles in RN as well as SCN resistance. These results could contribute to a better understanding of evolution and subfunctionalization of genes conferring resistance to multiple nematode species and provide a framework for further investigations., (© 2021 The Authors. The Plant Genome published by Wiley Periodicals LLC on behalf of Crop Science Society of America.)
- Published
- 2021
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20. TILLING-by-Sequencing + Reveals the Role of Novel Fatty Acid Desaturases (GmFAD2-2s) in Increasing Soybean Seed Oleic Acid Content.
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Lakhssassi N, Lopes-Caitar VS, Knizia D, Cullen MA, Badad O, El Baze A, Zhou Z, Embaby MG, Meksem J, Lakhssassi A, Chen P, AbuGhazaleh A, Vuong TD, Nguyen HT, Hewezi T, and Meksem K
- Subjects
- Fatty Acid Desaturases genetics, Gene Expression Regulation, Plant, Genotype, High-Throughput Nucleotide Sequencing, Mutation, Phenotype, Phylogeny, Plant Proteins genetics, Plants, Genetically Modified genetics, Seeds genetics, Glycine max genetics, DNA Mutational Analysis, Fatty Acid Desaturases metabolism, Mutagenesis, Site-Directed, Oleic Acid metabolism, Plant Proteins metabolism, Plants, Genetically Modified enzymology, Seeds enzymology, Glycine max enzymology
- Abstract
Soybean is the second largest source of oil worldwide. Developing soybean varieties with high levels of oleic acid is a primary goal of the soybean breeders and industry. Edible oils containing high level of oleic acid and low level of linoleic acid are considered with higher oxidative stability and can be used as a natural antioxidant in food stability. All developed high oleic acid soybeans carry two alleles; GmFAD2-1A and GmFAD2-1B . However, when planted in cold soil, a possible reduction in seed germination was reported when high seed oleic acid derived from GmFAD2-1 alleles were used. Besides the soybean fatty acid desaturase ( GmFAD2-1 ) subfamily, the GmFAD2-2 subfamily is composed of five members, including GmFAD2-2A , GmFAD2-2B , GmFAD2-2C , GmFAD2-2D , and GmFAD2-2E . Segmental duplication of GmFAD2-1A / GmFAD2-1B , GmFAD2-2A/GmFAD2-2C , GmFAD2-2A/GmFAD2-2D , and GmFAD2-2D/GmFAD2-2C have occurred about 10.65, 27.04, 100.81, and 106.55 Mya, respectively. Using TILLING-by-Sequencing+ technology, we successfully identified 12, 8, 10, 9, and 19 EMS mutants at the GmFAD2-2A , GmFAD2-2B , GmFAD2-2C , GmFAD2-2D , and GmFAD2-2E genes, respectively. Functional analyses of newly identified mutants revealed unprecedented role of the five GmFAD2-2A , GmFAD2-2B , GmFAD2-2C , GmFAD2-2D , and GmFAD2-2E members in controlling the seed oleic acid content. Most importantly, unlike GmFAD2-1 members, subcellular localization revealed that members of the GmFAD2-2 subfamily showed a cytoplasmic localization, which may suggest the presence of an alternative fatty acid desaturase pathway in soybean for converting oleic acid content without substantially altering the traditional plastidial/ER fatty acid production.
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- 2021
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21. TILLING-by-Sequencing + to Decipher Oil Biosynthesis Pathway in Soybeans: A New and Effective Platform for High-Throughput Gene Functional Analysis.
- Author
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Lakhssassi N, Zhou Z, Cullen MA, Badad O, El Baze A, Chetto O, Embaby MG, Knizia D, Liu S, Neves LG, and Meksem K
- Subjects
- Fatty Acid Desaturases genetics, Fatty Acid Desaturases metabolism, Mutation genetics, Plant Proteins genetics, Glycine max genetics, Plant Proteins metabolism, Soybean Oil metabolism, Glycine max metabolism
- Abstract
Reverse genetic approaches have been widely applied to study gene function in crop species; however, these techniques, including gel-based TILLING, present low efficiency to characterize genes in soybeans due to genome complexity, gene duplication, and the presence of multiple gene family members that share high homology in their DNA sequence. Chemical mutagenesis emerges as a genetically modified-free strategy to produce large-scale soybean mutants for economically important traits improvement. The current study uses an optimized high-throughput TILLING by target capture sequencing technology, or TILLING-by-Sequencing
+ (TbyS+ ), coupled with universal bioinformatic tools to identify population-wide mutations in soybeans. Four ethyl methanesulfonate mutagenized populations (4032 mutant families) have been screened for the presence of induced mutations in targeted genes. The mutation types and effects have been characterized for a total of 138 soybean genes involved in soybean seed composition, disease resistance, and many other quality traits. To test the efficiency of TbyS+ in complex genomes, we used soybeans as a model with a focus on three desaturase gene families, GmSACPD , GmFAD2 , and GmFAD3 , that are involved in the soybean fatty acid biosynthesis pathway. We successfully isolated mutants from all the six gene family members. Unsurprisingly, most of the characterized mutants showed significant changes either in their stearic, oleic, or linolenic acids. By using TbyS+ , we discovered novel sources of soybean oil traits, including high saturated and monosaturated fatty acids in addition to low polyunsaturated fatty acid contents. This technology provides an unprecedented platform for highly effective screening of polyploid mutant populations and functional gene analysis. The obtained soybean mutants from this study can be used in subsequent soybean breeding programs for improved oil composition traits.- Published
- 2021
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22. Soybean TILLING-by-Sequencing+ reveals the role of novel GmSACPD members in unsaturated fatty acid biosynthesis while maintaining healthy nodules.
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Lakhssassi N, Zhou Z, Liu S, Piya S, Cullen MA, El Baze A, Knizia D, Patil GB, Badad O, Embaby MG, Meksem J, Lakhssassi A, AbuGhazaleh A, Hewezi T, and Meksem K
- Subjects
- Alleles, Fatty Acids, Unsaturated, Plant Proteins genetics, Seeds, Glycine max genetics
- Abstract
Developing soybean lines with high levels of stearic acid is a primary goal of the soybean industry. Most high-stearic-acid soybeans carry different GmSACPD-C mutated alleles. However, due to the dual role of GmSACPD-C in seeds and nodule development, all derived deleterious GmSACPD-C mutant alleles are of extremely poor agronomic value because of defective nodulation. The soybean stearoyl-acyl carrier protein desaturase (GmSACPD) gene family is composed of five members. Comparative genomics analysis indicated that SACPD genes were duplicated and derived from a common ancestor that is still present in chlorophytic algae. Synteny analysis showed the presence of segment duplications between GmSACPD-A/GmSACPD-B, and GmSACPD-C/GmSACPD-D. GmSACPD-E was not contained in any duplicated segment and may be the result of tandem duplication. We developed a TILLING by Target Capture Sequencing (Tilling-by-Sequencing+) technology, a versatile extension of the conventional TILLING by sequencing, and successfully identified 12, 14, and 18 ethyl methanesulfonate mutants at the GmSACPD-A, GmSACPD-B, and GmSACPD-D genes, respectively. Functional analysis of all identified mutants revealed an unprecedented role of GmSACPD-A, GmSACPD-B, and GmSACPD-D in unsaturated fatty acid biosynthesis without affecting nodule development and structure. This discovery will positively impact the development of high-stearic-acid lines to enhance soybean nutritional value without potential developmental tradeoffs., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2020
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23. Optimization of Ultrasonicated Kaempferol Extraction from Ocimum basilicum Using a Box-Behnken Design and Its Densitometric Validation.
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Altemimi AB, Mohammed MJ, Yi-Chen L, Watson DG, Lakhssassi N, Cacciola F, and Ibrahim SA
- Abstract
Kaempferol (KA) is a natural flavonol that can be found in plants and plant-derived foods with a plethora of different pharmacological properties. In the current study, we developed an efficient extraction method for the isolation of KA from ultrasonicated basil leaves ( Ocimum basilicum ). We successfully employed a Box-Behnken design (BBD) in order to investigate the effect of different extraction variables including methanol concentration (40-80%), extraction temperature (40-60 °C), and extraction time (5-15 min). The quantification of KA yield was carried out by employing a validated densitometric high performance thin layer chromatography in connection with ultraviolet detection (HPTLC-VIS). The obtained data showed that the quadratic polynomial model (R
2 = 0.98) was the most appropriate. The optimized ultrasonic extraction yielded 94.7 ng/spot of KA when using methanol (79.99%) at 60 °C for 5 min. When using toluene-ethyl acetate-formic acid (70:30:1 v / v / v ) as a solvent, KA was detected in basil leaves at an Retention factor (Rf) value of 0.26 at 330 nm. Notably, the analytical method was successfully validated with a linear regression of R2 = 0.99, which reflected a good linear relationship. The developed HPTLC-VIS method in this study was precise, accurate, and robust due to the lower obtained results from both the percent relative standard deviation (%RSD) and SEM of the O. basilicum. The antioxidant activity of KA (half maximal inhibitory concentration (IC50 ) = 0.68 μg/mL) was higher than that of the reference ascorbic acid (IC50 = 0.79 μg/mL) and butylated hydroxytoluene (BHT) (IC50 = 0.88 μg/mL). The development of economical and efficient techniques is very important for the extraction and quantification of important pharmaceutical compounds such as KA.- Published
- 2020
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24. EMS-Induced Mutagenesis of Clostridium carboxidivorans for Increased Atmospheric CO 2 Reduction Efficiency and Solvent Production.
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Lakhssassi N, Baharlouei A, Meksem J, Hamilton-Brehm SD, Lightfoot DA, Meksem K, and Liang Y
- Abstract
Clostridium carboxidivorans (P7) is one of the most important solvent-producing bacteria capable of fermenting syngas (CO, CO
2 , and H2 ) to produce chemical commodities when grown as an autotroph. This study aimed to develop ethyl methanesulfonate (EMS)-induced P7 mutants that were capable of growing in the presence of CO2 as a unique source of carbon with increased solvent formation and atmospheric CO2 reduction to limit global warming. Phenotypic analysis including growth and end product characterization of the P7 wild type (WT) demonstrated that this strain grew better at 25 °C than 37 °C when CO2 served as the only source of carbon. In the current study, 55 mutagenized P7-EMS mutants were developed by using 100 mM and 120 mM EMS. Interestingly, using a forward genetic approach, three out of the 55 P7-EMS mutants showed a significant increase in ethanol, butyrate, and butanol production. The three P7-EMS mutants presented on average a 4.68-fold increase in concentrations of ethanol when compared to the P7-WT. Butyric acid production from 3 P7-EMS mutants contained an average of a 3.85 fold increase over the levels observed in the P7-WT cultures under the same conditions (CO2 only). In addition, one P7-EMS mutant presented butanol production (0.23 ± 0.02 g/L), which was absent from the P7-WT under CO2 conditions. Most of the P7-EMS mutants showed stability of the obtained end product traits after three transfers. Most importantly, the amount of reduced atmospheric CO2 increased up to 8.72 times (0.21 g/Abs) for ethanol production and up to 8.73 times higher (0.16 g/Abs) for butyrate than the levels contained in the P7-WT. Additionally, to produce butanol, the P7-EMSIII-J mutant presented 0.082 g/Abs of CO2 reduction. This study demonstrated the feasibility and effectiveness of employing EMS mutagenesis in generating solvent-producing anaerobic bacteria mutants with improved and novel product formation and increased atmospheric CO2 reduction efficiency.- Published
- 2020
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25. A pathogenesis-related protein GmPR08-Bet VI promotes a molecular interaction between the GmSHMT08 and GmSNAP18 in resistance to Heterodera glycines.
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Lakhssassi N, Piya S, Bekal S, Liu S, Zhou Z, Bergounioux C, Miao L, Meksem J, Lakhssassi A, Jones K, Kassem MA, Benhamed M, Bendahmane A, Lambert K, Boualem A, Hewezi T, and Meksem K
- Subjects
- Animals, Plant Diseases genetics, Salicylic Acid, Glycine max genetics, Disease Resistance genetics, Tylenchoidea
- Abstract
Soybean cyst nematode (SCN, Heterodera glycines) is the most devastating pest affecting soybean production worldwide. SCN resistance requires both the GmSHMT08 and the GmSNAP18 in 'Peking'-type resistance. Here, we describe the molecular interaction between GmSHMT08 and GmSNAP18, which is potentiated by a pathogenesis-related protein GmPR08-Bet VI. Like GmSNAP18 and GmSHMT08, GmPR08-Bet VI expression was induced in response to SCN and its overexpression decreased SCN cysts by 65% in infected transgenic soybean roots. Overexpression of GmPR08-Bet VI did not have an effect on SCN resistance when the two cytokinin-binding sites in GmPR08-Bet VI were mutated, indicating a new role of GmPR08-Bet VI in SCN resistance. GmPR08-Bet VI was mapped to a QTL for resistance to SCN using different mapping populations. GmSHMT08, GmSNAP18 and GmPR08-Bet VI localize to the cytosol and plasma membrane. GmSNAP18 expression and localization hyper-accumulated at the plasma membrane and was specific to the root cells surrounding the nematode in SCN-resistant soybeans. Genes encoding key components of the salicylic acid signalling pathway were induced under SCN infection. GmSNAP18 and GmPR08-Bet VI were also induced under salicylic acid and cytokinin exogenous treatments, while GmSHMT08 was induced only when the resistant GmSNAP18 was present, pointing to the presence of a molecular crosstalk between SCN-resistant genes and defence genes. Expression analysis of GmSHMT08 and GmSNAP18 identified the need of a minimum expression requirement to trigger the SCN resistance reaction. These results provide insight into a new response mechanism towards plant nematode resistance involving haplotype compatibility, gene dosage and hormone signalling., (© 2020 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)
- Published
- 2020
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26. Mutations at the Serine Hydroxymethyltransferase Impact its Interaction with a Soluble NSF Attachment Protein and a Pathogenesis-Related Protein in Soybean.
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Lakhssassi N, Piya S, Knizia D, El Baze A, Cullen MA, Meksem J, Lakhssassi A, Hewezi T, and Meksem K
- Abstract
Resistance to soybean cyst nematodes (SCN) in "Peking-type" resistance is bigenic, requiring Rhg4-a and rhg1-a . Rhg4-a encodes a serine hydroxymethyltransferase (GmSHMT08) and rhg1-a encodes a soluble NSF attachment protein (GmSNAP18). Recently, it has been shown that a pathogenesis-related protein, GmPR08-Bet VI, potentiates the interaction between GmSHMT08 and GmSNAP18. Mutational analysis using spontaneously occurring and ethyl methanesulfonate (EMS)-induced mutations was carried out to increase our knowledge of the interacting GmSHMT08/GmSNAP18/GmPR08-Bet VI multi-protein complex. Mutations affecting the GmSHMT08 protein structure (dimerization and tetramerization) and interaction sites with GmSNAP18 and GmPR08-Bet VI proteins were found to impact the multi-protein complex. Interestingly, mutations affecting the PLP/THF substrate binding and catalysis did not affect the multi-protein complex, although they resulted in increased susceptibility to SCN. Most importantly, GmSHMT08 and GmSNAP18 from PI88788 were shown to interact within the cell, being potentiated in the presence of GmPR08-Bet VI. In addition, we have shown the presence of incompatibility between the GmSNAP18 ( rhg1-b ) of PI88788 and GmSHMT08 ( Rhg4-a ) from Peking. Components of the reactive oxygen species (ROS) pathway were shown to be induced in the SCN incompatible reaction and were mapped to QTLs for resistance to SCN using different mapping populations.
- Published
- 2020
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27. Ultrasound applications in poultry meat processing: A systematic review.
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Al-Hilphy AR, Al-Temimi AB, Al Rubaiy HHM, Anand U, Delgado-Pando G, and Lakhssassi N
- Subjects
- Animals, Food Handling instrumentation, Freezing, Poultry, Salmonella genetics, Salmonella isolation & purification, Ultrasonics instrumentation, Vacuum, Food Handling methods, Meat analysis, Ultrasonics methods
- Abstract
Ultrasound (US) is classified as a nonthermal treatment and it is used in food processing at a frequency range between 20 kHz and 1 MHz. Cavitation bubbles occur when the US strength is high enough to generate rarefaction that exceeds the intermolecular attraction forces in the medium. Currently, US is widely used in meat industries to enhance procedures, such as meat tenderization, emulsification mass transfer, marination, freezing, homogenization, crystallization, drying, and microorganism inactivation. In addition, combining ultrasonic energy with a sanitizing agent has a synergistic effect on microbial reduction. When poultry meat is treated using US, the expected quality is often better than the traditional methods, such as sanitization and freezing. US can be considered as a novel green technology for tenderizing and decontamination of poultry meat since both Escherichia coli and Salmonella are sensible to US. US improves the physical and chemical properties of meat proteins and can lead to a decrease in the α-helix in intramuscular protease complex in addition to a reduction in the viscosity coefficients. Therefore, ultrasonic treatment can be applied to enhance the textural properties of chicken meat. US can also be used to improve the drying rate when used under vacuum, compared with other traditional techniques. This review focuses on the potential of US applications in the management of poultry industries as the demand for good quality meat proteins is increasing worldwide., (© 2020 Institute of Food Technologists®.)
- Published
- 2020
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28. Purification of Bioactive Peptide with Antimicrobial Properties Produced by Saccharomyces cerevisiae .
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Al-Sahlany STG, Altemimi AB, Al-Manhel AJA, Niamah AK, Lakhssassi N, and Ibrahim SA
- Abstract
A variety of organisms produce bioactive peptides that express inhibition activity against other organisms. Saccharomyces cerevisiae is considered the best example of a unicellular organism that is useful for studying peptide production. In this study, an antibacterial peptide was produced and isolated from Saccharomyces cerevisiae (Baker's yeast) by an ultrafiltration process (two membranes with cut-offs of 2 and 10 kDa) and purified using the ÄKTA Pure 25 system. Antibacterial peptide activity was characterized and examined against four bacterial strains including Gram-positive and Gram-negative bacteria. The optimum condition for yeast growth and antibacterial peptide production against both Escherichia. coli and Klebsiella aerogenes was 25-30 °C within a 48 h period. The isolated peptide had a molecular weight of 9770 Da, was thermostable at 50-90 °C for 30 min, and tolerated a pH range of 5-7 at 4 °C and 25 °C during the first 24 h, making this isolated antibacterial peptides suitable for use in sterilization and thermal processes, which are very important aspect in food production. The isolated antibacterial peptide caused a rapid and steady decline in the number of viable cells from 2 to 2.3 log units of gram-negative strains and from 1.5 to 1.8 log units of gram-positive strains during 24 h of incubation. The isolated antibacterial peptide from Saccharomyces cerevisiae may present a potential biopreservative compound in the food industry exhibiting inhibition activity against gram-negative and gram-positive bacteria.
- Published
- 2020
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29. Development of a Millet Starch Edible Film Containing Clove Essential Oil.
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Al-Hashimi AG, Ammar AB, G L, Cacciola F, and Lakhssassi N
- Abstract
Medicinal plants contain various secondary metabolites. The present study analyzed the essential oil of buds from clove (Syzygium aromaticum L.; Family: Myrtaceae) using gas chromatography-mass spectrometry (GC-MS). GC-MS analysis showed the presence of six major phytoconstituents, such as eugenol (66.01%), caryophyllene (19.88%), caryophyllene oxide (5.80%), phenol, 2-methoxy-4-(2-propenyl)-acetate (4.55%), and humulene (3.75%). The effect of clove essential oils (CEO) at 0%, 1%, 2%, and 3% ( w / w ) on the mechanical and barrier properties of starch films was evaluated. The tensile strength (TS) and elongation (E) of films with clove essential oil were 6.25 ± 0.03 MPa and 5.67% ± 0.08%, respectively. The antioxidant activity of the films significantly increased the millet starch film and presented the lowest antioxidant activity (0.3%) at a 30 minute incubation for the control sample, while increasing CEO fraction in the starch film lead to an increase in antioxidant activity, and the 3% CEO combined film presented the highest antioxidant activity (15.96%) at 90 min incubation. This finding could be explained by the incorporation of clove oil containing antioxidant properties that significantly increased with the incorporation of CEO ( p < 0.05). A zone of inhibition ranging from 16 to 27 mm in diameter was obtained when using a concentration of CEO ranging from 1% to 3%. We also observed the presence of an antimicrobial activity on several tested microorganism including Escherichia coli , Pseudomonas aeruginosa , Enterobacter sp, Bacillus cereus , Staphylococcus aureus , and Trichoderma fungi . Thus, the current study reveals the possibility of using a millet starch edible film as a preservation method., Competing Interests: There is no conflict of interest.
- Published
- 2020
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30. Assessment of Phenotypic Variations and Correlation among Seed Composition Traits in Mutagenized Soybean Populations.
- Author
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Zhou Z, Lakhssassi N, Cullen MA, El Baz A, Vuong TD, Nguyen HT, and Meksem K
- Subjects
- Carbohydrates analysis, Fatty Acids analysis, Phenotype, Plant Breeding, Plant Oils analysis, Seeds chemistry, Seeds drug effects, Seeds genetics, Soybean Proteins analysis, Soybean Proteins drug effects, Glycine max chemistry, Glycine max genetics, Ethyl Methanesulfonate adverse effects, Mutation, Glycine max drug effects
- Abstract
Soybean [ Glycine max (L.) Merr.] seed is a valuable source of protein and oil worldwide. Traditionally, the natural variations were heavily used in conventional soybean breeding programs to select desired traits. However, traditional plant breeding is encumbered with low frequencies of spontaneous mutations. In mutation breeding, genetic variations from induced mutations provide abundant sources of alterations in important soybean traits; this facilitated the development of soybean germplasm with modified seed composition traits to meet the different needs of end users. In this study, a total of 2366 'Forrest'-derived M2 families were developed for both forward and reverse genetic studies. A subset of 881 M3 families was forward genetically screened to measure the contents of protein, oil, carbohydrates, and fatty acids. A total of 14 mutants were identified to have stable seed composition phenotypes observed in both M3 and M4 generations. Correlation analyses have been conducted among ten seed composition traits and compared to a collection of 103 soybean germplasms. Mainly, ethyl methanesulfonate (EMS) mutagenesis had a strong impact on the seed-composition correlation that was observed among the 103 soybean germplasms, which offers multiple benefits for the soybean farmers and industry to breed for desired multiple seed phenotypes.
- Published
- 2019
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31. A Comprehensive Review on Medicinal Plants as Antimicrobial Therapeutics: Potential Avenues of Biocompatible Drug Discovery.
- Author
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Anand U, Jacobo-Herrera N, Altemimi A, and Lakhssassi N
- Abstract
The war on multidrug resistance (MDR) has resulted in the greatest loss to the world's economy. Antibiotics, the bedrock, and wonder drug of the 20th century have played a central role in treating infectious diseases. However, the inappropriate, irregular, and irrational uses of antibiotics have resulted in the emergence of antimicrobial resistance. This has resulted in an increased interest in medicinal plants since 30-50% of current pharmaceuticals and nutraceuticals are plant-derived. The question we address in this review is whether plants, which produce a rich diversity of secondary metabolites, may provide novel antibiotics to tackle MDR microbes and novel chemosensitizers to reclaim currently used antibiotics that have been rendered ineffective by the MDR microbes. Plants synthesize secondary metabolites and phytochemicals and have great potential to act as therapeutics. The main focus of this mini-review is to highlight the potential benefits of plant derived multiple compounds and the importance of phytochemicals for the development of biocompatible therapeutics. In addition, this review focuses on the diverse effects and efficacy of herbal compounds in controlling the development of MDR in microbes and hopes to inspire research into unexplored plants with a view to identify novel antibiotics for global health benefits.
- Published
- 2019
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32. Whole-genome re-sequencing reveals the impact of the interaction of copy number variants of the rhg1 and Rhg4 genes on broad-based resistance to soybean cyst nematode.
- Author
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Patil GB, Lakhssassi N, Wan J, Song L, Zhou Z, Klepadlo M, Vuong TD, Stec AO, Kahil SS, Colantonio V, Valliyodan B, Rice JH, Piya S, Hewezi T, Stupar RM, Meksem K, and Nguyen HT
- Subjects
- Animals, Base Sequence, Female, Genetic Loci, Genome, Plant, Haplotypes, Plant Diseases parasitology, Promoter Regions, Genetic, Protein Structure, Tertiary, Glycine max parasitology, DNA Copy Number Variations, Disease Resistance genetics, Plant Diseases genetics, Glycine max genetics, Tylenchoidea pathogenicity
- Abstract
Soybean cyst nematode (SCN) is the most devastating plant-parasitic nematode. Most commercial soybean varieties with SCN resistance are derived from PI88788. Resistance derived from PI88788 is breaking down due to narrow genetic background and SCN population shift. PI88788 requires mainly the rhg1-b locus, while 'Peking' requires rhg1-a and Rhg4 for SCN resistance. In the present study, whole genome re-sequencing of 106 soybean lines was used to define the Rhg haplotypes and investigate their responses to the SCN HG-Types. The analysis showed a comprehensive profile of SNPs and copy number variations (CNV) at these loci. CNV of rhg1 (GmSNAP18) only contributed towards resistance in lines derived from PI88788 and 'Cloud'. At least 5.6 copies of the PI88788-type rhg1 were required to confer SCN resistance, regardless of the Rhg4 (GmSHMT08) haplotype. However, when the GmSNAP18 copies dropped below 5.6, a 'Peking'-type GmSHMT08 haplotype was required to ensure SCN resistance. This points to a novel mechanism of epistasis between GmSNAP18 and GmSHMT08 involving minimum requirements for copy number. The presence of more Rhg4 copies confers resistance to multiple SCN races. Moreover, transcript abundance of the GmSHMT08 in root tissue correlates with more copies of the Rhg4 locus, reinforcing SCN resistance. Finally, haplotype analysis of the GmSHMT08 and GmSNAP18 promoters inferred additional levels of the resistance mechanism. This is the first report revealing the genetic basis of broad-based resistance to SCN and providing new insight into epistasis, haplotype-compatibility, CNV, promoter variation and its impact on broad-based disease resistance in plants., (© 2019 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)
- Published
- 2019
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33. TTL Proteins Scaffold Brassinosteroid Signaling Components at the Plasma Membrane to Optimize Signal Transduction in Arabidopsis.
- Author
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Amorim-Silva V, García-Moreno Á, Castillo AG, Lakhssassi N, Esteban Del Valle A, Pérez-Sancho J, Li Y, Posé D, Pérez-Rodriguez J, Lin J, Valpuesta V, Borsani O, Zipfel C, Macho AP, and Botella MA
- Subjects
- Arabidopsis genetics, Cell Membrane metabolism, Gene Expression Regulation, Plant genetics, Gene Expression Regulation, Plant physiology, Membrane Proteins metabolism, Signal Transduction genetics, Signal Transduction physiology, Arabidopsis metabolism, Arabidopsis Proteins metabolism, Brassinosteroids metabolism
- Abstract
Brassinosteroids (BRs) form a group of steroidal hormones essential for plant growth, development, and stress responses. BRs are perceived extracellularly by plasma membrane receptor-like kinases that activate an interconnected signal transduction cascade, leading to the transcriptional regulation of BR-responsive genes. TETRATRICOPEPTIDE THIOREDOXIN-LIKE ( TTL ) genes are specific for land plants, and their encoded proteins are defined by the presence of protein-protein interaction motives, that is, an intrinsic disordered region at the N terminus, six tetratricopeptide repeat domains, and a C terminus with homology to thioredoxins. TTL proteins thus likely mediate the assembly of multiprotein complexes. Phenotypic, molecular, and genetic analyses show that TTL proteins are positive regulators of BR signaling in Arabidopsis ( Arabidopsis thaliana ). TTL3 directly interacts with a constitutively active BRASSINOSTEROID INSENSITIVE1 (BRI1) receptor kinase, BRI1-SUPPRESSOR1 phosphatase, and the BRASSINAZOLE RESISTANT1 transcription factor and associates with BR-SIGNALING KINASE1, BRASSINOSTEROID INSENSITIVE2 kinases, but not with BRI1-ASSOCIATED KINASE1. A functional TTL3-green fluorescent protein (GFP) shows dual cytoplasmic plasma membrane localization. Depleting the endogenous BR content reduces plasma membrane localization of TTL3-GFP, while increasing BR content causes its plasma membrane relocalization, where it strengthens the association of BR signaling components. Our results reveal that TTL proteins promote BR responses and suggest that TTL proteins may function as scaffold proteins by bringing together cytoplasmic and plasma membrane BR signaling components., (© 2019 American Society of Plant Biologists. All rights reserved.)
- Published
- 2019
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34. Genome reorganization of the GmSHMT gene family in soybean showed a lack of functional redundancy in resistance to soybean cyst nematode.
- Author
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Lakhssassi N, Patil G, Piya S, Zhou Z, Baharlouei A, Kassem MA, Lightfoot DA, Hewezi T, Barakat A, Nguyen HT, and Meksem K
- Subjects
- Alleles, Animals, Gene Duplication, Haplotypes, Host-Parasite Interactions genetics, Host-Parasite Interactions immunology, Mutagenesis, Phylogeny, Plant Diseases genetics, Plant Diseases immunology, Plant Diseases parasitology, Polymorphism, Single Nucleotide, Glycine max parasitology, Disease Resistance genetics, Gene Expression Regulation, Plant, Genome, Plant, Mutation, Plant Proteins genetics, Glycine max genetics, Tylenchoidea physiology
- Abstract
In soybeans, eighteen members constitute the serine hydroxymethyltransferase (GmSHMT) gene family, of which the cytosolic-targeted GmSHMT08c member has been reported to mediate resistance to soybean cyst nematode (SCN). This work presents a comprehensive study of the SHMT gene family members, including synteny, phylogeny, subcellular localizations, haplotypes, protein homology modeling, mutational, and expression analyses. Phylogenetic analysis showed that SHMT genes are divided into four classes reflecting their subcellular distribution (cytosol, nucleus, mitochondrion, and chloroplast). Subcellular localization of selected GmSHMT members supports their in-silico predictions and phylogenetic distribution. Expression and functional analyses showed that GmSHMT genes display many overlapping, but some divergent responses during SCN infection. Furthermore, mutational analysis reveals that all isolated EMS mutants that lose their resistance to SCN carry missense and nonsense mutations at the GmSHMT08c, but none of the Gmshmt08c mutants carried mutations in the other GmSHMT genes. Haplotype clustering analysis using the whole genome resequencing data from a collection of 106 diverse soybean germplams (15X) was performed to identify allelic variants and haplotypes within the GmSHMT gene family. Interestingly, only the cytosolic-localized GmSHMT08c presented SNP clusters that were associated with SCN resistance, supporting our mutational analysis. Although eight GmSHMT members respond to the nematode infestation, functional and mutational analysis has shown the absence of functional redundancy in resistance to SCN. Structural analysis and protein homology modeling showed the presence of spontaneous mutations at important residues within the GmSHMT proteins, suggesting the presence of altered enzyme activities based on substrate affinities. Due to the accumulation of mutations during the evolution of the soybean genome, the other GmSHMT members have undergone neofunctionalization and subfunctionalization events.
- Published
- 2019
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35. Evaluation of the antimicrobial activities of ultrasonicated spinach leaf extracts using RAPD markers and electron microscopy.
- Author
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Altemimi A, Lakhssassi N, Abu-Ghazaleh A, and Lightfoot DA
- Subjects
- Humans, Microbial Sensitivity Tests, Microscopy, Electron, Random Amplified Polymorphic DNA Technique, Anti-Bacterial Agents pharmacology, Escherichia coli O157 drug effects, Plant Extracts pharmacology, Plant Leaves metabolism, Spinacia oleracea metabolism, Staphylococcus aureus drug effects
- Abstract
Spinach (Spinacia oleracea L.) leaves represent an important dietary source of nutrients, antioxidants and antimicrobials. As such, spinach leaves play an important role in health and have been used in the treatment of human diseases since ancient times. Here, the aims were to optimize the extraction methods for recovering antimicrobial substances of spinach leaves, determine the minimum inhibitory concentrations (MICs) of the antimicrobial substances against Escherichia coli and Staphylococcus aureus and, finally, evaluate the effects of spinach leaves' antimicrobials on bacterial DNA using central composite face-centered methods. The effect of the extracts on both Gram-positive and Gram-negative bacterial models was examined by scanning electron microscopy (SEM) and random amplification of polymorphic (bacterial) DNA (RAPD). The optimal extraction conditions were at 45 °C, ultrasound power of 44% and an extraction time of 23 min. The spinach extracts exhibited antimicrobial activities against both bacteria with MICs in the 60-100 mg/ml range. Interestingly, SEM showed that the treated bacterial cells appear damaged with a reduction in cell number. RAPD analysis of genomic DNA showed that the number and sizes of amplicons were decreased by treatments. Based on these results, it was inferred that spinach leaf extracts exert bactericidal activities by both inducing mutations in DNA and causing cell wall disruptions.
- Published
- 2017
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36. Systematic Mutagenesis of Serine Hydroxymethyltransferase Reveals an Essential Role in Nematode Resistance.
- Author
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Kandoth PK, Liu S, Prenger E, Ludwig A, Lakhssassi N, Heinz R, Zhou Z, Howland A, Gunther J, Eidson S, Dhroso A, LaFayette P, Tucker D, Johnson S, Anderson J, Alaswad A, Cianzio SR, Parrott WA, Korkin D, Meksem K, and Mitchum MG
- Subjects
- Animals, Genetic Complementation Test, Genetic Testing, Glycine Hydroxymethyltransferase chemistry, Models, Molecular, Mutation genetics, Plants, Genetically Modified, Glycine max immunology, Tylenchoidea pathogenicity, Virulence, Disease Resistance, Glycine Hydroxymethyltransferase genetics, Mutagenesis genetics, Plant Diseases immunology, Plant Diseases parasitology, Glycine max enzymology, Glycine max parasitology, Tylenchoidea physiology
- Abstract
Rhg4 is a major genetic locus that contributes to soybean cyst nematode (SCN) resistance in the Peking-type resistance of soybean ( Glycine max ), which also requires the rhg1 gene. By map-based cloning and functional genomic approaches, we previously showed that the Rhg4 gene encodes a predicted cytosolic serine hydroxymethyltransferase (GmSHMT08); however, the novel gain of function of GmSHMT08 in SCN resistance remains to be characterized. Using a forward genetic screen, we identified an allelic series of GmSHMT08 mutants that shed new light on the mechanistic aspects of GmSHMT08 -mediated resistance. The new mutants provide compelling genetic evidence that Peking-type rhg1 resistance in cv Forrest is fully dependent on the GmSHMT08 gene and demonstrates that this resistance is mechanistically different from the PI 88788-type of resistance that only requires rhg1 We also demonstrated that rhg1-a from cv Forrest, although required, does not exert selection pressure on the nematode to shift from HG type 7, which further validates the bigenic nature of this resistance. Mapping of the identified mutations onto the SHMT structural model uncovered key residues for structural stability, ligand binding, enzyme activity, and protein interactions, suggesting that GmSHMT08 has additional functions aside from its main enzymatic role in SCN resistance. Lastly, we demonstrate the functionality of the GmSHMT08 SCN resistance gene in a transgenic soybean plant., (© 2017 American Society of Plant Biologists. All Rights Reserved.)
- Published
- 2017
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37. Phytochemicals: Extraction, Isolation, and Identification of Bioactive Compounds from Plant Extracts.
- Author
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Altemimi A, Lakhssassi N, Baharlouei A, Watson DG, and Lightfoot DA
- Abstract
There are concerns about using synthetic phenolic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) as food additives because of the reported negative effects on human health. Thus, a replacement of these synthetics by antioxidant extractions from various foods has been proposed. More than 8000 different phenolic compounds have been characterized; fruits and vegetables are the prime sources of natural antioxidants. In order to extract, measure, and identify bioactive compounds from a wide variety of fruits and vegetables, researchers use multiple techniques and methods. This review includes a brief description of a wide range of different assays. The antioxidant, antimicrobial, and anticancer properties of phenolic natural products from fruits and vegetables are also discussed., Competing Interests: The authors declare no conflicts of interest.
- Published
- 2017
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38. Stearoyl-Acyl Carrier Protein Desaturase Mutations Uncover an Impact of Stearic Acid in Leaf and Nodule Structure.
- Author
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Lakhssassi N, Colantonio V, Flowers ND, Zhou Z, Henry J, Liu S, and Meksem K
- Subjects
- Alleles, Amino Acid Sequence, Base Sequence, Conserved Sequence, DNA Mutational Analysis, Gene Expression Regulation, Plant, Genetic Testing, Leghemoglobin metabolism, Mixed Function Oxygenases chemistry, Mixed Function Oxygenases genetics, Models, Molecular, Plant Leaves anatomy & histology, Plant Proteins chemistry, Plant Proteins genetics, Seeds metabolism, Glycine max genetics, Structural Homology, Protein, Mixed Function Oxygenases metabolism, Mutation genetics, Plant Leaves metabolism, Plant Proteins metabolism, Root Nodules, Plant metabolism, Glycine max enzymology, Stearic Acids metabolism
- Abstract
Stearoyl-acyl carrier protein desaturase (SACPD-C) has been reported to control the accumulation of seed stearic acid; however, no study has previously reported its involvement in leaf stearic acid content and impact on leaf structure and morphology. A subset of an ethyl methanesulfonate mutagenized population of soybean ( Glycine max ) 'Forrest' was screened to identify mutants within the GmSACPD-C gene. Using a forward genetics approach, one nonsense and four missense Gmsacpd-c mutants were identified to have high levels of seed, nodule, and leaf stearic acid content. Homology modeling and in silico analysis of the GmSACPD-C enzyme revealed that most of these mutations were localized near or at conserved residues essential for diiron ion coordination. Soybeans carrying Gmsacpd-c mutations at conserved residues showed the highest stearic acid content, and these mutations were found to have deleterious effects on nodule development and function. Interestingly, mutations at nonconserved residues show an increase in stearic acid content yet retain healthy nodules. Thus, random mutagenesis and mutational analysis allows for the achievement of high seed stearic acid content with no associated negative agronomic characteristics. Additionally, expression analysis demonstrates that nodule leghemoglobin transcripts were significantly more abundant in soybeans with deleterious mutations at conserved residues of GmSACPD-C. Finally, we report that Gmsacpd-c mutations cause an increase in leaf stearic acid content and an alteration of leaf structure and morphology in addition to differences in nitrogen-fixing nodule structure., (© 2017 American Society of Plant Biologists. All Rights Reserved.)
- Published
- 2017
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39. [Complete removable denture retained by symphyseal implant].
- Author
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Abdelkoui A, Lakhssassi N, Merzouk N, and Berrada S
- Subjects
- Aged, 80 and over, Dental Prosthesis Design, Denture Design, Denture Retention, Humans, Male, Mandible surgery, Maxilla surgery, Dental Prosthesis, Implant-Supported, Denture, Overlay, Jaw, Edentulous surgery, Mouth, Edentulous surgery
- Abstract
Introduction: Edentulous patients often hope for stable and retentive prostheses. In very unfavorable anatomophysiological circumstances, the implant-retained removable full denture is a simple and reliable option that considerably optimizes the prosthetic balance. We present the case of one of those patients taken in charge in our department., Observation: A full edentulous 82 years old male patient was referred for a prosthetic rehabilitation. He presented with a negative mandibular crest and a very tonic peri-prosthetic musculature in the anterior region. He refused a bone augmentation surgery; we performed a piezographic mandibular prosthesis retained by a single symphyseal implant in a lingual position. The denture was stable and retentive. Comfort and masticatory efficiency were satisfactory and the psychological integration of the prosthesis was improved., Discussion: Several studies focusing on octogenarian patients concluded that a complete removable denture retained by a single symphyseal implant is a simple, efficient and cost-effective option. Studies including more patients are needed., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)
- Published
- 2017
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40. The soybean GmSNAP18 gene underlies two types of resistance to soybean cyst nematode.
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Liu S, Kandoth PK, Lakhssassi N, Kang J, Colantonio V, Heinz R, Yeckel G, Zhou Z, Bekal S, Dapprich J, Rotter B, Cianzio S, Mitchum MG, and Meksem K
- Subjects
- Alleles, Animals, Cloning, Molecular, DNA, Plant genetics, Genetic Complementation Test, Haplotypes, High-Throughput Nucleotide Sequencing, Host-Parasite Interactions, INDEL Mutation, Models, Genetic, Polymorphism, Single Nucleotide, Disease Resistance genetics, Genes, Plant, Nematoda physiology, Soybean Proteins genetics, Glycine max genetics, Glycine max parasitology
- Abstract
Two types of resistant soybean (Glycine max (L.) Merr.) sources are widely used against soybean cyst nematode (SCN, Heterodera glycines Ichinohe). These include Peking-type soybean, whose resistance requires both the rhg1-a and Rhg4 alleles, and PI 88788-type soybean, whose resistance requires only the rhg1-b allele. Multiple copy number of PI 88788-type GmSNAP18, GmAAT, and GmWI12 in one genomic segment simultaneously contribute to rhg1-b resistance. Using an integrated set of genetic and genomic approaches, we demonstrate that the rhg1-a Peking-type GmSNAP18 is sufficient for resistance to SCN in combination with Rhg4. The two SNAPs (soluble NSF attachment proteins) differ by only five amino acids. Our findings suggest that Peking-type GmSNAP18 is performing a different role in SCN resistance than PI 88788-type GmSNAP18. As such, this is an example of a pathogen resistance gene that has evolved to underlie two types of resistance, yet ensure the same function within a single plant species.
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- 2017
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41. Characterization of the Soluble NSF Attachment Protein gene family identifies two members involved in additive resistance to a plant pathogen.
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Lakhssassi N, Liu S, Bekal S, Zhou Z, Colantonio V, Lambert K, Barakat A, and Meksem K
- Subjects
- Animals, Nematoda pathogenicity, Plant Proteins chemistry, Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins chemistry, Glycine max genetics, Glycine max immunology, Glycine max parasitology, Tetratricopeptide Repeat, Plant Immunity genetics, Plant Proteins genetics, Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins genetics
- Abstract
Proteins with Tetratricopeptide-repeat (TPR) domains are encoded by large gene families and distributed in all plant lineages. In this study, the Soluble NSF-Attachment Protein (SNAP) subfamily of TPR containing proteins is characterized. In soybean, five members constitute the SNAP gene family: GmSNAP18, GmSNAP11, GmSNAP14, GmSNAP02, and GmSNAP09. Recently, GmSNAP18 has been reported to mediate resistance to soybean cyst nematode (SCN). Using a population of recombinant inbred lines from resistant and susceptible parents, the divergence of the SNAP gene family is analysed over time. Phylogenetic analysis of SNAP genes from 22 diverse plant species showed that SNAPs were distributed in six monophyletic clades corresponding to the major plant lineages. Conservation of the four TPR motifs in all species, including ancestral lineages, supports the hypothesis that SNAPs were duplicated and derived from a common ancestor and unique gene still present in chlorophytic algae. Syntenic analysis of regions harbouring GmSNAP genes in soybean reveals that this family expanded from segmental and tandem duplications following a tetraploidization event. qRT-PCR analysis of GmSNAPs indicates a co-regulation following SCN infection. Finally, genetic analysis demonstrates that GmSNAP11 contributes to an additive resistance to SCN. Thus, GmSNAP11 is identified as a novel minor gene conferring resistance to SCN.
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- 2017
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42. Characterization of the FAD2 Gene Family in Soybean Reveals the Limitations of Gel-Based TILLING in Genes with High Copy Number.
- Author
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Lakhssassi N, Zhou Z, Liu S, Colantonio V, AbuGhazaleh A, and Meksem K
- Abstract
Soybean seed oil typically contains 18-20% oleic acid. Increasing the content of oleic acid is beneficial for health and biodiesel production. Mutations in FAD2-1 genes have been reported to increase seed oleic acid content. A subset of 1,037 mutant families from a mutagenized soybean cultivar (cv.) Forrest population was screened using reverse genetics (TILLING) to identify mutations within FAD2 genes. Although no fad2 mutants were identified using gel-based TILLING, four fad2-1A and one fad2-1B mutants were identified to have high seed oleic acid content using forward genetic screening and subsequent target sequencing. TILLING has been successfully used as a non-transgenic reverse genetic approach to identify mutations in genes controlling important agronomic traits. However, this technique presents limitations in traits such as oil composition due to gene copy number and similarities within the soybean genome. In soybean, FAD2 are present as two copies, FAD2-1 and FAD2-2. Two FAD2-1 members: FAD2-1A and FAD2-1B; and three FAD2-2 members: FAD2-2A, FAD2-2B , and FAD2-2C have been reported. Syntenic, phylogenetic, and in silico analysis revealed two additional members constituting the FAD2 gene family: GmFAD2-2D and GmFAD2-2E , located on chromosomes 09 and 15, respectively. They are presumed to have diverged from other FAD2-2 members localized on chromosomes 19 ( GmFAD2-2A and GmFAD2-2B ) and 03 ( GmFAD2-2C ). This work discusses alternative solutions to the limitations of gel-based TILLING in functional genomics due to high copy number and multiple paralogs of the FAD2 gene family in soybean.
- Published
- 2017
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43. [Atraumatic bone expansion: Interest of piezo-surgery, conicals expanders and immediate implantation combination].
- Author
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Iraqui O, Lakhssassi N, Berrada S, and Merzouk N
- Subjects
- Alveolar Process, Alveolar Ridge Augmentation instrumentation, Alveolar Ridge Augmentation methods, Bone Transplantation instrumentation, Bone Transplantation methods, Dental Implants, Female, Humans, Middle Aged, Tissue Expansion methods, Bone Lengthening instrumentation, Bone Lengthening methods, Dental Implantation, Endosseous instrumentation, Dental Implantation, Endosseous methods, Piezosurgery instrumentation, Piezosurgery methods, Tissue Expansion Devices
- Abstract
The durability of dental implants depends on the presence of a 1mm coating bone sheath all around the fixture. Therefore, bone resorption represents a challenge for the practitioner. Bone expansion is a surgical technique that allows the management of horizontal bone atrophy. Cortical bone splitting allows for an enlargement of the residual crest by displacement of the vestibular bone flap. The immediate placement of implants secures the widening and allows for a 97% survival rate. However, bone expansion is hard to undertake in sites with high bone density. Furthermore, the use of traditional instruments increases patient's stress and the risk for an interruptive fracture during bone displacement. Non-traumatic bone expansion is one solution to this problem. The combination of piezo-surgery and conical expanders allows for a secured displacement of the selected bone flap as well as an immediate implant placement, avoiding the risk of slipping, overheating, or fracture, all within an undeniable operative comfort. Non-traumatic bone expansion is a reliable, reproducible, conservative, and economical in time and cost procedure. We describe our atraumatic bone expension and immediate implant placement technique in high bone density sites and illustrate it by a clinical case., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)
- Published
- 2016
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44. A SNARE-Like Protein and Biotin Are Implicated in Soybean Cyst Nematode Virulence.
- Author
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Bekal S, Domier LL, Gonfa B, Lakhssassi N, Meksem K, and Lambert KN
- Subjects
- Alleles, Amino Acid Sequence, Animals, Biotin genetics, Genetic Linkage, Genomics, Helminth Proteins genetics, Molecular Sequence Data, Polymorphism, Single Nucleotide, Protein Transport, RNA, Messenger genetics, RNA, Messenger metabolism, SNARE Proteins chemistry, SNARE Proteins genetics, Tylenchoidea genetics, Tylenchoidea metabolism, Biotin metabolism, Helminth Proteins metabolism, SNARE Proteins metabolism, Glycine max parasitology, Tylenchoidea pathogenicity
- Abstract
Phytoparasitic nematodes that are able to infect and reproduce on plants that are considered resistant are referred to as virulent. The mechanism(s) that virulent nematodes employ to evade or suppress host plant defenses are not well understood. Here we report the use of a genetic strategy (allelic imbalance analysis) to associate single nucleotide polymorphisms (SNPs) with nematode virulence genes in Heterodera glycines, the soybean cyst nematode (SCN). To accomplish this analysis, a custom SCN SNP array was developed and used to genotype SCN F3-derived populations grown on resistant and susceptible soybean plants. Three SNPs reproducibly showed allele imbalances between nematodes grown on resistant and susceptible plants. Two candidate SCN virulence genes that were tightly linked to the SNPs were identified. One SCN gene encoded biotin synthase (HgBioB), and the other encoded a bacterial-like protein containing a putative SNARE domain (HgSLP-1). The two genes mapped to two different linkage groups. HgBioB contained sequence polymorphisms between avirulent and virulent nematodes. However, the gene encoding HgSLP-1 had reduced copy number in virulent nematode populations and appears to produce multiple forms of the protein via intron retention and alternative splicing. We show that HgSLP-1 is an esophageal-gland protein that is secreted by the nematode during plant parasitism. Furthermore, in bacterial co-expression experiments, HgSLP-1 co-purified with the SCN resistance protein Rhg1 α-SNAP, suggesting that these two proteins physically interact. Collectively our data suggest that multiple SCN genes are involved in SCN virulence, and that HgSLP-1 may function as an avirulence protein and when absent it helps SCN evade host defenses.
- Published
- 2015
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- View/download PDF
45. The Arabidopsis tetratricopeptide thioredoxin-like gene family is required for osmotic stress tolerance and male sporogenesis.
- Author
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Lakhssassi N, Doblas VG, Rosado A, del Valle AE, Posé D, Jimenez AJ, Castillo AG, Valpuesta V, Borsani O, and Botella MA
- Subjects
- Arabidopsis drug effects, Arabidopsis metabolism, Arabidopsis physiology, Arabidopsis Proteins classification, Arabidopsis Proteins genetics, Computational Biology, Data Mining, Gene Expression Profiling, Gene Expression Regulation, Plant, Genes, Plant, Genes, Reporter, Glucuronidase genetics, Glucuronidase metabolism, Multigene Family, Mutation, Phylogeny, Plant Roots genetics, Plant Roots metabolism, Plant Roots physiology, Plants, Genetically Modified drug effects, Plants, Genetically Modified genetics, Plants, Genetically Modified metabolism, Plants, Genetically Modified physiology, Pollen genetics, Pollen metabolism, Pollen physiology, Promoter Regions, Genetic, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Sodium Chloride pharmacology, Adaptation, Physiological, Arabidopsis genetics, Arabidopsis Proteins metabolism, Stress, Physiological
- Abstract
TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) proteins are characterized by the presence of six tetratricopeptide repeats in conserved positions and a carboxyl-terminal region known as the thioredoxin-like domain with homology to thioredoxins. In Arabidopsis (Arabidopsis thaliana), the TTL gene family is composed by four members, and the founder member, TTL1, is required for osmotic stress tolerance. Analysis of sequenced genomes indicates that TTL genes are specific to land plants. In this study, we report the expression profiles of Arabidopsis TTL genes using data mining and promoter-reporter β-glucuronidase fusions. Our results show that TTL1, TTL3, and TTL4 display ubiquitous expression in normal growing conditions but differential expression patterns in response to osmotic and NaCl stresses. TTL2 shows a very different expression pattern, being specific to pollen grains. Consistent with the expression data, ttl1, ttl3, and ttl4 mutants show reduced root growth under osmotic stress, and the analysis of double and triple mutants indicates that TTL1, TTL3, and TTL4 have partially overlapping yet specific functions in abiotic stress tolerance while TTL2 is involved in male gametophytic transmission.
- Published
- 2012
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46. [Bacterial DNA alteration by plasma generated atomic nitrogen. Real-time PCR detection contribution].
- Author
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Lakhssassi N, Cousty S, Villeger S, Diouf A, Ricard A, and Sixou M
- Subjects
- Base Sequence, DNA Primers, DNA, Bacterial chemistry, DNA, Bacterial isolation & purification, Methicillin Resistance, Nitrogen, Nucleic Acid Conformation, Nucleic Acid Denaturation, DNA, Bacterial genetics, Geobacillus stearothermophilus genetics, Helicobacter pylori genetics, Polymerase Chain Reaction methods, Staphylococcus aureus genetics
- Abstract
Aims: Bacterial sterilization by the technology of plasma in post-discharge shows a growing interest. The main appeal of this new process resides in its action at dry and low temperature (60 degrees C). This technology would be therefore useful for the complex medical equipment, sensitive to the oxidization, humidity and/or requiring a temperature lower than 60 degrees C. The objective of this survey is to demonstrate the activity of an atomic flux emanating a plasma of pure molecular nitrogen on the bacterial DNA: does the plasma of nitrogen damage the genetic material?, Materials and Methods: The bacteria tested (Bacillus stearothermophilus, Staphylococcus aureus MRSA and Helicobacter pylori) are cultivated on suitable agar, and the bacterial DNA is extracted from every CFU by the technique of the columns (High Pure PCR Template, Roche). Every quantity of DNA extracted is diluted in 1 ml pure water. Then, 50 microl of each of these solutions of DNA are laid down in sterile Nunclon's plates holes, which undergo an advanced emptiness cycle during 60 minutes. The DNA residues will be then introduced during 40 minutes in a plasma sterilization surrounding wall (Plasmalyse), Satelec) where the debit of nitrogen, the pressure and the temperature are adjusted respectively to 1 L x min(-1), 5 Torrs and 60 degrees C. The DNA so ''plasmalysé'', is recovered then by aspiration in 500 mul pure water and processed to undergo an amplification/detection by Real-Time PCR (LightCycler2.0, Roche). The DNA ''plasmalysé'' will be compared to the intact DNA control(1), to the DNA control control(2) having undergone the cycle of emptiness solely, as well as to the DNA control(3) solely heated to 60 degrees C during 40 min., Results: The amplification curves demonstrated that the only advanced emptiness and the only heat don't have any activity on the bacterial DNA. On the other hand, the DNA ''plasmalysé'' shows a deterioration of the amplified sequences., Conclusion: The genomic bacterial DNA, once extracted, is damaged by the gaseous flux of nitrogen plasma. A new sterilization process of the medical material will presumably impose itself in medium-term.
- Published
- 2006
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47. [Efficacy variation of erythromycin and spiramycin on periopathogens in aggressive periodontitis. An in vitro comparative study].
- Author
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Lakhssassi N and Sixou M
- Subjects
- Adult, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Erythromycin pharmacology, Humans, Microbial Sensitivity Tests, Reproducibility of Results, Spiramycin pharmacology, Erythromycin therapeutic use, Periodontitis drug therapy, Spiramycin therapeutic use
- Abstract
Aims: Erythromycin (ERY) and spiramycin (SPI) are the most frequently prescribed macrolides by dentists. However, the emergence of resistant anaerobic subgingival bacteria imposes an increased vigilance. This study aims to compare these macrolides efficacy on principal periopathogens., Materials and Methods: Twenty adult patients with aggressive periodontitis were selected and a total of 60 samples were taken from subgingival flora. Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, Peptostreptococcus micros and Actinobacillus actinomycetemcomitans were isolated according to J. Slots's rapid identification method. The susceptibilities to ERY and SPI were studied using disk diffusion susceptibility test and minimum inhibitory concentration test (MIC test)., Results: The efficiency variability of ERY and SPI on the 50 isolated anaerobic periopathogens was present either interindividually (between different patients) and intra-individually (within the same patient). While 68% of the tested anaerobic bacteria were sensitive to SPI (22% resistant), only 54% were sensitive to ERY (34% resistant). Although moderate, the efficacy of SPI seemed more regular in general than ERY: it's variation coefficient (40%) is lower than the ERY one (53%). The 7 A. actinomycetemcomitans tested showed all a high resistance., Conclusion: In a general way, the spectre of activity of SPI is stacked in that of ERY. However, this study shows a better and regular activity of SPI on the main tested periopathogens. These results are in favour of the use of SPI in periodontology when penicillins and doxycycline are not useful because specific problems are identified (allergy, pregnancy...).
- Published
- 2005
- Full Text
- View/download PDF
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