Search

Fungal endophytes are valued for biosynthesizing chemically diverse metabolic cascade with interesting biological activities. In the current investigation, two compounds were isolated from Penicillium polonicum, an endophyte of Zingiber officinale. The active moieties, glaucanic acid (1) and dihydrocompactin acid (2) were isolated from the ethyl acetate extract of P. polonicum and characterized by NMR and mass spectroscopy. Further, bioactive potential of the isolated compounds was evaluated by antimicrobial, antioxidant and cytotoxicity assays. Compounds 1 and 2 displayed antifungal activity against phytopathogen Colletotrichum gloeosporioides with more than 50% reduction in its growth. Both the compounds exhibited antioxidant activity against free radicals (DPPH and ABTS) and cytotoxicity activity against cancer cell lines respectively. The compounds, glaucanic acid and dihydrocompactin acid are being reported for the first time from an endophytic fungus. This is the first report on the biological activities of Dihydrocompactin acid produced by endophytic fungal strain. [ABSTRACT FROM AUTHOR]

Genus Plantago of Plantaginaceae family is bestowed with a repertoire of structurally diverse secondary metabolites that have not only been used as therapeutics but also effect the plant physiology by conferring adaptive advantages under stress. Assuming that domestication process in plants has influenced their secondary metabolites, we performed a comparative transcriptome of wild and cultivated species of Plantago to analyze the variation in the expression of genes related to secondary metabolite pathways. GO and KEGG analysis of DEGs in wild species showed their enrichment in abiotic stresses, oxidation–reduction and secondary metabolite related pathways. Overall, we found upregulation of genes of carotenoid, flavonoid and phenylpropanoid, isoprenoid, terpenoid and alkaloid pathways in wild species of Plantago in particular, P. lanceolata while mucilage pathway-related genes showed higher expression in P. ovata. Moreover, transcriptome data presented putative transcription factors associated with terpenoids, carotenoid and phenylpropanoid biosynthetic pathways which were also identified using co-expression analysis of cluster 9 (secondary metabolite enriched gene cluster). Taken together, the genomic resource obtained from the present study form a valuable repository of genetic information for elucidating and exploring the secondary metabolic circuitry of Plantagos. Further, information on the regulatory aspects of genes related to secondary metabolites, shall aid in the enhanced production of valuable metabolites in these plants. [ABSTRACT FROM AUTHOR]

The family Asparagaceae (subfamily Scilloideae, APG III, Botanical Journal of the Linnean Society 161:105–121, 2009) constitutes approximately 1000 species in about 33 genera of deciduous bulbous geophytes with long history of medicinal utilities. However, satisfactory delimitation of genera as well as species boundaries within most genera still remain doubtful for the lack of reliable discriminating characters with morphological traits showing continuous variation. Detailed cytogenetic characterization and thorough comparative analysis is still scanty in this group and thus can provide supportive taxonomical data besides serving as basis for further genomic studies. This group showcases diverse cytogenetic characters studied across 4 tribes: Hyacintheae, Urgineeae, Ornithogaleae and Oziroëeae. Cytogenetic investigation has not yet been initiated in more than 50% of accepted species, studies mostly limited to chromosome counts or conventional karyotyping methods. Somatic chromosome counts have been reported in around 378 species varying from 2n = 4 in Ornithogaleae to 2n = 150 in Hyacintheae and the basic ancestral chromosome number of x = 10 is proposed for the subfamily and secondary base numbers presumed to arise by descending dysploidy followed by polyploidization leading to such variation. Meiotic analysis and genome size estimation is reported in very few species and requires further investigation. Karyotype in most taxa exhibits a general pattern characterized by asymmetry with predominance of acrocentric chromosomes. Fluorochrome banding by CMA/DAPI staining and FISH although reported in very few species revealed characteristic patterns in different taxa, with potential taxonomic utilities. Thus, comparison of compiled data depicted some patterns of chromosomal diversity within the subfamily Scilloideae but study of more taxa is required for prediction of trends. [ABSTRACT FROM AUTHOR]

Neurofibromatosis type 1 (NF1) is a multisystemic hereditary disorder associated with an increased risk of benign and malignant tumor formation predominantly on the skin, bone, and peripheral nervous system. It has been reported that out of all the NF1 cases, more than 95% cases develop the disease due to heterozygous loss-of-function variants in Neurofibromin (NF1) gene. However, identification of NF1 causative variants by presently recommended method of gene-targeted Sanger sequencing is challenging and cost-intensive due to the large size of the NF1gene with 60 exons spanning about 350 kb. Further, conducting the genetic studies is difficult in low resource regions and among families with the limited financial capabilities, restricting them from availing diagnostic as well as proper disease management measures. Here, we studied a three-generation family from Jammu and Kashmir state in India, with multiple affected family members showing clinical indications of NF1. We combinedly used two applications, Whole Exome Sequencing (WES) and Sanger sequencing, for this study and discovered a nonsense variant NM_000267.3:c.2041C>T (NP_000258.1:p.Arg681Ter*) in exon 18 of NF1 gene in a cost effective manner. In silico analyses further substantiated the pathogenicity of this novel variant. The study also emphasized on the role of Next Generation Sequencing (NGS) as a cost-effective method for the discovery of pathogenic variants in disorders with known phenotypes found in large sized candidate genes. The current study is the first study based on the genetic characterization of NF1 from Jammu and Kashmir–India, highlighting the importance of the described methodology adopted for the identification and understanding of the disease in low resource region. The early diagnosis of genetic disorders would open the door to appropriate genetic counseling, reducing the disease burden in the affected families and the general population at large. [ABSTRACT FROM AUTHOR]

Objectives: There are many multifactorial causes for Congenital Heart Defects (CHDs) in which both genetic and non-genetic factors play role. MTHFD1 and CBS are two of the key enzymes that plays pivotal role in the metabolic pathway of homocysteine. Most of the studies revealed that genes involved in folate/homocysteine pathways are involved in the occurrence of CHDs. The present study was planned to investigate the role of common polymorphisms in MTHFD1 and CBS gene in children with CHD in Jammu region of Jammu and Kashmir UT. Material and Methods: A total of 160 (80 CHD patients and 80 controls) children were enrolled for the present case-control study. After extraction of genomic DNA genotyping of SNP MTHFD1 G1958A(rs2236225) was done by PCR-RFLP and CBS 844ins68 polymorphism was done by PCR technique. Results: Our results show that there is no significant association between MTHFD1G1958A and CBS 844ins68 polymorphism with CHD. In case of SNP MTHFD1 G1958A allele A found to be higher in both patient and control group and inCBS 844ins68 polymorphism frequency of risk allele 'I' found higher in cases (0.06) as compared to controls (0.04). The homozygous genotype for 844ins68 (II) was found absent in both the patients and control group. Conclusion: We conclude that both MTHFD1 G1958A and CBS 844ins68 polymorphism were not found to be genetic risk factor in the development of CHD in population of Jammu region of Jammu and Kashmir UT. [ABSTRACT FROM AUTHOR]

Saffron (Crocus sativus L.) is triploid (2 n = 3x = 24, x = 8), which limits its improvement through crop breeding programs. This study was initiated to induce hexaploidy with the intent of restoring sexual stability in saffron. Corms were treated with colchicine concentrations of 0.0%, 0.025%, 0.05%, and 0.1% for 3-h, 6-h, and 9-h. A total of 16 in-vitro shoots showed signs of polyploidization. These colchiploid shoots showed slow but robust growth and produced large-sized cormlets (6.0 g) compared to the control (2.8 g). Leaf epidermal cell morphology, stomatal size and density showed evidence of polyploidization. Hexaploidy (2 n = 6x = 48) was confirmed by root-tip cytology. The hexaploid corms germinated but could not establish in the field. We were able to develop a protocol for in-vitro induction of hexaploidy in C. sativus, but the subsequent growth of hexaploid corms in the field remains a major challenge in restoring the sexual stability in saffron. [ABSTRACT FROM AUTHOR]

Plantagos are important economical and medicinal plants that possess several bioactive secondary metabolites, such as phenolics, iridoids, triterpenes, and alkaloids. Triterpenoids are the ubiquitous and dynamic secondary metabolites that are deployed by plants for chemical interactions and protection under biotic/abiotic stress. Plantago ovata, a cultivated species, is the source of psyllium, while Plantago major, a wild species, has significant therapeutic potential. Wild species are considered more tolerant to stressful conditions in comparison to their cultivated allies. In view of this, the present study aimed to decipher the terpenoid biosynthetic pathway operative in P. ovata and P. major using a comparative transcriptomics approach. Majority of terpenoid biosynthetic genes were observed as upregulated in P. major including rate limiting genes of MVA (HMGR) and MEP (DXR) pathways and genes (α-AS, BAS, SM, and CYP716) involved in ursolic acid biosynthesis, an important triterpenoid prevalent in Plantago species. The HPLC output further confirmed the higher concentration of ursolic acid in P. major as compared to P. ovata leaf samples, respectively. In addition to terpenoid biosynthesis, KEGG annotation revealed the involvement of differentially expressed unigenes in several metabolic pathways, aminoacyl-tRNA biosynthesis, biosynthesis of antibiotics, and biosynthesis of secondary metabolites. MYB was found as the most abundant transcription factor family in Plantago transcriptome. We have been able to generate valuable information which can help in improving terpenoid production in Plantago. Additionally, the present study has laid a strong foundation for deciphering other important metabolic pathways in Plantago. [ABSTRACT FROM AUTHOR]

Looking at the population's behavior by taking samples is quite uncertain due to its big and dynamic structure and unimaginable variability. All quantitative sampling approaches aim to draw a representative sample from the population so that the results of the studying samples can then be generalized back to the population. The probability of detecting a true effect of a study largely depends on the sample size and if taking small samples will give lowers statistical power, higher risk of missing a meaningful underlying difference. The probability of rejecting the null hypothesis i.e., finding significant difference using the sample largely depends upon the statistical power. There are a lot of online tools used for calculating the sample size, but none tell us about the availability of samples from single site in a fixed span. This study aims to provide an efficient calculation method for the availability of samples during a specific period of a research study which is an important question to be answered during the research study design. So, we have designed a spreadsheet-based sample availability calculator tool implemented in MS-Excel 2007. [ABSTRACT FROM AUTHOR]

Natural products and their semi synthesized molecules have been used as efficient antibiotics since a long time. The present global health scenario has raised the demand for novel antimicrobial agents and drug targets that are effective against drug resistant pathogens, emerging infections etc. The current study has promoted the antibacterial activity of the glucoside labdane 'neoandrographolide', isolated from the methanolic extract of the medicinal plant Andrographis paniculata. Further modification at its glucoside hydroxyl groups to generate ester and acetonide derivatives was done and the antibacterial potential of these compounds was screened against common bacterial pathogens. Among various derivatives, 4',6'-O-(4-methoxybenzylidene) neoandrographolide exhibited promising results. In addition, molecular modeling study of the active compound was also explored to identify its probable binding mode on the bacterial target. The present study reported antibacterial activity of neoandrographolide derivatives for first time and also the bioactive molecule, 4',6'-O-(4-methoxybenzylidene) neoandrographolide was examined as a potent antibacterial agent against different strains. [ABSTRACT FROM AUTHOR]

Squalene epoxidase (SQE) is a crucial regulatory enzyme for the biosynthesis of several important classes of compounds including sterols and triterpenoids. The present paper identified and characterised five SQE genes (GgSQE1 to GgSQE5) from Glycyrrhiza glabra through transcriptome data mining and homology-based cloning, for the first time. The phylogenetic analysis implied their functional divergence. The ORF corresponding to one of the five SQEs, namely, GgSQE1, was cloned and studied for its function in a heterologous system, following transient and stable expressions. The transient expression followed by GgSQE1 encoding protein purification suggested approximately 58.0-kDa protein following the predicted molecular mass of the deduced protein. The gene expression profiling based on qRT-PCR indicated its highest expression (6.4-folds) in the 10-month-old roots. Furthermore, ABA (12.4-folds) and GA3 (2.47) treatments upregulated the expression of GgSQE1 in the shoots after 10 and 12 hours, respectively, which was also reflected in glycyrrhizin accumulation. The inductive effects of ABA and GA3 over GgSQE1 expression were also confirmed through functional analysis of GgSQE1 promoters using GUS fusion construct. Stable constitutive expression of GgSQE1 in Nicotiana tabacum modulated the sterol contents. The study could pave the way for understanding the metabolic flux regulation concerning biosynthesis of related sterols and triterpenoids. [ABSTRACT FROM AUTHOR]

The cruciferous vegetables are richest sources of isothiocyanates and among them, allyl isothiocyanate (AITC) is one of the major constituents. It has been known to possess various activities of therapeutic interest. Keeping this in view, the present study was planned to investigate antioxidant capacity of AITC using Cupric Reducing Antioxidant Capacity (CUPRAC) Assay, 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay, β-Carotene bleaching (BCB) assay and superoxide anion scavenging assay. The antimutagenic potency of AITC was determined by modifying Vibrio harveyi bioluminescence assay against direct acting mutagen 4-nitro-o-phenylenediamine (NPD) and indirect acting mutagens 2-acetylaminofluorene (2-AAF), 7,12-Dimethylbenz[a]anthracene (DMBA) in presence and absence of S9. Furthermore, the antihemolytic activity was evaluated using hemolysis assay. Among the different activities carried out, it was observed that AITC exhibited efficient antimutagenic potential against direct acting mutagen NPD and indirect acting mutagens 2-AAF and DMBA in the presence as well as absence of S9 fraction in Vibrio harveyi bioluminescence assay. Overall, our results established the efficiency of AITC to act as strong antimutagenic agent, efficient anti-hemolytic agent and mild antioxidant agent thus, making AITC an interesting candidate to be further explored for drug discovery. [ABSTRACT FROM AUTHOR]

Dynamic consortium of microbial communities (bacteria, fungi, protists, viruses, and nematodes) colonizing multiple tissue types and coevolving conclusively with the host plant is designated as a plant microbiome. The interplay between plant and its microbial mutualists supports several agronomic functions, establishing its crucial role in plant beneficial activities. Deeper functional and mechanistic understanding of plant-microbial ecosystems will render many "ecosystem services" by emulating symbiotic interactions between plants, soil, and microbes for enhanced productivity and sustainability. Therefore, microbiome engineering represents an emerging biotechnological tool to directly add, remove, or modify properties of microbial communities for higher specificity and efficacy. The main goal of microbiome engineering is enhancement of plant functions such as biotic/abiotic stresses, plant fitness and productivities, etc. Various ecological-, biochemical-, and molecular-based approaches have come up as a new paradigm for disentangling many microbiome-based agromanagement hurdles. Furthermore, multidisciplinary approaches provide a predictive framework in achieving a reliable and sustainably engineered plant-microbiome for stress physiology, nutrient recycling, and high-yielding disease-resistant genotypes. [ABSTRACT FROM AUTHOR]

The availability of diverse germplasm of any crop is an important genetic resource to mine the genes that may assist in attaining food as well as the nutritional quality of the crop. In the present study, a total of 10 RAPD markers were used for the first time in the Kashmir apple germplasm to elucidate diversity among 19 apple cultivars collected from various parts of the Valley. The discriminatory power of each random primer was observed using various parameters like: polymorphic information content, resolving power and marker index. A total of 70 polymorphic bands were observed with a percentage polymorphism of 83.33. Cultivars differentiated through mutations like Oregon Spur, Reeka Red, and Silver Spur were also included in this study and have shown identical banding patterns among each other. The dendrogram generated by using NTSYS grouped cultivars into two major clusters with various degrees of sub-clustering within the cluster. These findings will be helpful for further research programs on apple and have implications in apple breeding as well as in conservation programs. [ABSTRACT FROM AUTHOR]

Tomato is an excellent model for studying fruit development, ripening, and other secondary metabolic pathways such as carotenoid biosynthetic pathway, flavonoid pathway, and many more. Tomato fruit development and ripening occurs under tight genetic control and involves the expression of thousands of genes affecting fruit quality and accumulation of pigments and metabolites. Here, we have described the development of a microarray platform that has allowed establishment of a framework for quantification of the expression of large number of genes and transcription factors possibly regulating various secondary metabolic pathways in tomato. To unravel the molecular mechanisms of fruit development and ripening, a tomato 60-mer oligonucleotide 44 K microarray along with the custom array for many genes and transcription factors was designed and validated in the fruit and leaf tissues. Comparative profiling of gene expression studies has allowed us to identify a large number of differentially expressed genes and transcription factors. Gene ontology revealed the involvement of these genes in various biological, cellular, and molecular processes like isoprenoid, terpenoid, pigment, ethylene biosynthesis, phytohormone signaling, and fruit ripening. Further, correlation, as well as differential expression studies, has revealed that several transcription factors like RIN, AGAMOUS, TAGL1, MYB, MADS-box etc. could be the possible regulators of various secondary metabolic pathways. The present study has identified various metabolites, their biosynthetic pathways and genes which may possibly be controlled by different transcription factors. The present findings have laid a base for understanding the transcriptional and metabolic shifts which occur in parallel during programmed fruit ripening and developmental processes in tomato. [ABSTRACT FROM AUTHOR]

The study reports 147 full-length WRKY genes based on the transcriptome analysis of Glycyrrhiza genus (G. glabra and G. uralensis). Additional motifs in G. glabra included DivIVA (GgWRKY20) and SerS Superfamily (GgWRKY21) at the C-terminal, and Coat family motifs (GgWRKY55) at the N-terminal of the proteins, while Exo70 exo cyst complex subunit of 338 amino acid (GuWRKY9) was present at the N-terminal of G. uralensis only. Plant Zn cluster super-family domain (17 WRKYs) and bZIP domain (2 WRKYs) were common between the two species. Based on the number of WRKY domains, sequence alignment and phylogenesis, the study identified GuWRKY27 comprising of 3 WRKY domains in G. uralensis and a new subgroup-IIf (10 members), having novel zinc finger pattern (C-X4-C-X22-HXH) in G. glabra. Multiple WRKY binding domains (1–11) were identified in the promoter regions of the GgWRKY genes indicating strong interacting network between the WRKY proteins. Tissue-specific expression of 25 GgWRKYs, under normal and treated conditions, revealed 11 of the 18 induction factor triggered response corroborating to response observed in AtWRKYs. The study identified auxin-responsive GgWRKY 55 & GgWRKY38; GA3 responsive GgWRKYs15&59 in roots and GgWRKYs8, 20, 38, 57 &58 in the shoots of the treated plant. GgWRKYs induced under various stresses included GgWRKY33 (cold), GgWRKY4 (senescence), GgWRKYs2, 28 & 33 (salinity) and GgWRKY40 (wounding). Overall, 23 GgWRKYs responded to abiotic stress, and 17 WRKYs were induced by hormonal signals. Of them 13 WRKYs responded to both suggesting inter-connection between hormone signalling and stress response. The present study will help in understanding the transcriptional reprogramming, protein-protein interaction and cross-regulation during stress and other physiological processes in the plant. [ABSTRACT FROM AUTHOR]

In this paper, we present a new online comprehensive database developed for genome-related information of Indian plants (dGRIP). In strict sense, dGRIP database displays for each species and genus, its chromosome number(s) with comprehensive cytogenetic data, genome size, ploidy, systematics and molecular genetics related to Indian angiosperms, gymnosperms, pteridophytes and bryophytes. The data are described in the form of datasheets encompassing 29 parameters available for users to consolidate the knowledge with respect to comprehensive cytogenetical details. The chromosome database is developed based on object-relational database management system (Sequence Query Language) and includes references from which the information was sourced. The online database is currently available at http://sbtju.in/Dgrip/index.html consists of a main page, project information, collaborators and search tools for each group, namely angiosperms, gymnosperms pteridophytes and bryophytes. Currently, the information is available for about 1500 species (Release 1.0); however, the dGRIP continues to expand with goal to include data of more than 17,000 plant species from India. [ABSTRACT FROM AUTHOR]

Withania somnifera (Ashwagandha) synthesizes a wide spectrum of triterpenoids that are produced via an intricate isoprenoid pathway whose biosynthetic and regulatory mechanism remains elusive. Their pharmacological examination position them as potent bioactive molecules, hence demanding their copious production. Previous investigations have revealed that P450 monooxygenases are pivotal enzymes involved in the biosynthetic machinery of various metabolites and assist in decorating their core skeletal structures. The present study entails the isolation and functional characterization of castasterone synthase (CYP85A69) from W. somnifera. The full length WsCYP85A69 , having an open reading frame of 1413 bp, encodes 470 amino acid residues. Further, in vitro conversion of 6-deoxocastasterone into castasterone validated its oxidative functionality. Product formation was confirmed using LC-PDA-MS with a m/z value of 506 [M+ACN]+. In planta transient over-expression of WsCYP85A69 significantly enhanced castasterone, stigmasterol and withanolides (WS-I, WS-II, WS-III). Artificial micro-RNA mediated silencing of WsCYP85A69 resulted in the reduced accumulation of castasterone, stigmasterol and withanolides (WS-I, WS-II, WS-III). Altogether, these non-complementary approaches plausibly suggest a key role of WsCYP85A69 in the biosynthesis of castasterone and the accumulation of withanolides and stigmasterol. Furthermore, a promoter analysis of WsCYP85A69 resulted in the identification of several potential cis -regulatory elements. Elicitations, given on the basis of identified cis -regulatory elements, demonstrated methyl jasmonate as an effective inducer of WsCYP85A69. Overall, these empirical findings suggest that functional characterization of WsCYP85A69 may conceivably be helpful to unravel the mechanism of brassinosteroids biosynthesis and could also pave the way for targeted metabolic engineering. [ABSTRACT FROM AUTHOR]

Key message: Functional characterization of WsMYC2 via artificial microRNA mediated silencing and transient over-expression displayed significant regulatory role vis-à-vis withanolides and stigmasterol biosyntheses in Withania somnifera. Further, metabolic intensification corroborated well with higher expression levels of putative pathway genes. Additionally, copious expression of WsMYC2 in response to exogenous elicitors resulted in enhanced withanolides production. Withania somnifera, a high value multipurpose medicinal plant, is a rich reservoir of structurally diverse and biologically active triterpenoids known as withanolides. W. somnifera has been extensively pursued vis-à-vis pharmacological and chemical studies. Nonetheless, there exists fragmentary knowledge regarding the metabolic pathway and the regulatory aspects of withanolides biosynthesis. Against this backdrop, a jasmonate-responsive MYC2 transcription factor was identified and functionally characterized from W. somnifera. In planta transient over-expression of WsMYC2 showed significant enhancement of mRNA transcript levels which corroborated well with the enhanced content of withanolides and stigmasterol. Further, a comparative analysis of expression levels of some of the genes of triterpenoid pathway viz. WsCAS, WsCYP85A, WsCYP90B and WsCYP710A in corroboration with the over-expression and silencing of WsMYC2 suggested its positive influence on their regulation. These corroboratory approaches suggest that WsMYC2 has cascading effect on over-expression of multiple pathway genes leading to the increased triterpenoid biosynthesis in infiltered plants. Further, the functional validation of WsMYC2 was carried out by artificial micro-RNA mediated silencing. It resulted in significant reduction of withanolides and stigmasterol levels, indicative of crucial role of WsMYC2 in the regulation of their biosyntheses. Taken together, these non-complementary approaches provided unambiguous understanding of the regulatory role of WsMYC2 in context to withanolides and stigmasterol biosyntheses. Furthermore, the upstream promoter of WsMYC2 presented several cis-regulatory elements primarily related to phytohormone responsiveness. WsMYC2 displayed inducible nature in response to MeJA. It had substantial influence on the higher expression of WsMYC2 which was in consonance with enhanced accumulation of withanolides. [ABSTRACT FROM AUTHOR]

microRNAs represent small endogenous RNAs which are known to play a crucial role in various plant metabolic processes. Carrot being an important vegetable crop, represents one of the richest sources of carotenoids and anthocyanins. Most of the studies on microRNAs have been conducted in the aerial parts of the plants. However, carrot has the rare distinction of storing these compounds in roots. Therefore, carrot represents a good model system to unveil the regulatory roles of miRNAs in the underground edible part of the plant. For the first time, we report the genome wide identification and expression profiling of miRNAs in two contrasting color variants of carrot namely Orange Red and Purple Black using RNA-seq. Illumina sequencing resulted in the generation of 25.5M and 18.9M reads in Orange Red and Purple Black libraries, respectively. In total, 144 and 98 (read count >10), conserved microRNAs and 36 and 66 novel microRNAs were identified in Orange Red and Purple Black, respectively. Functional categorization and differential gene expression revealed the presence of several miRNA genes targeting various secondary metabolic pathways including carotenoid and anthocyanin biosynthetic pathways in the two libraries. 11 known and 2 novel microRNAs were further validated using Stem-Loop PCR and qRT-PCR. Also, target validation was performed for selected miRNA genes using RLM-RACE approach. The present work has laid a foundation towards understanding of various metabolic processes, particularly the color development in carrot. This information can be further employed in targeted gene expression for increasing the carotenoid and anthocyanin content in crop plants. [ABSTRACT FROM AUTHOR]

Bioactive natural compounds, isolated from fungal endophytes, play a promising role in the search for novel drugs. They are an inspiring source for researchers due to their enormous structural diversity and complexity. During the present study fungal endophytes were isolated from a well-known medicinal shrub, Berberis aristata DC. and were explored for their antagonistic and antioxidant potential. B. aristata, an important medicinal shrub with remarkable pharmacological properties, is native to Northern Himalayan region. A total of 131 endophytic fungal isolates belonging to eighteen species and nine genera were obtained from three hundred and thirty surface sterilized segments of different tissues of B. aristata. The isolated fungi were classified on the basis of morphological and molecular analysis. Diversity and species richness was found to be higher in leaf tissues as compared to root and stem. Antibacterial activity demonstrated that the crude ethyl acetate extract of 80% isolates exhibited significant results against one or more bacterial pathogens. Ethyl acetate extract of Alternaria macrospora was found to have potential antibacterial activity. Significant antioxidant activity was also found in crude ethyl acetate extracts of Alternaria alternata and Aspergillus flavus. Similarly, antagonistic activity of the fungal endophytes revealed that all antagonists possessed inhibition potential against more than one fungal pathogen. This study is an important step towards tapping endophytic fungal diversity for bioactive metabolites which could be a step forward towards development of novel therapeutic agents. [ABSTRACT FROM AUTHOR]

Microtubule actin cross-linking factor 1 (MACF1) gene variant rs2296172 has recently been associated with type 2 diabetes (T2D). However, this variant has never been evaluated as such in Indian populations. In the present replication study, we genotyped variant rs2296172 by Taqman allele discrimination assay in 432 individuals belonging to the Bania caste group from Punjab, India. The single-nucleotide polymorphism (SNP) was evaluated for association with T2D, in a population based candidate gene case-control association study design, by estimating odds ratio with 95% confidence interval. The SNP rs2296172 of MACF1 was found to be significantly associated with T2D (p = 0.02) and odds ratio (OR) = 1.59 (1.06-2.38) at 95% CI. We further emphasize that the Indian population as such is a conglomeration of various endogamous population groups. It is critical that such replication studies be carried out in various populations to find association of variants to T2D susceptibility and understand genetic heterogeneity. However, it is important to avoid pooling of samples to address the concern of population stratification. [ABSTRACT FROM AUTHOR]

Saffron (Crocus sativus L) is a triploid (2n = 3x = 24), sterile geophyte which can only be propagated by means of underground vegetative corms. Since corm multiplication does not induce genome variations, therefore, the entire saffron population is expected to have a similar genetic makeup. Keeping in view the economic importance of the plant and the factors responsible for its low yield, the present investigation has been undertaken to establish an in vitro ethyl methanesulfonate (EMS) mutagenesis protocol followed by characterization of the induced variability in the advanced generations. The present report is limited to standardization of in vitro mutagenesis protocol only. Among the mutagenic treatments tested, concentrations ranging from 0.1 to 0.5% EMS showed a varied survival of explants. Based on various growth parameters, the LD50 was calculated to be 0.3% EMS for 3 h. Among the two types of explants analyzed, the corm explant gave better results for in vitro survival and the growth parameters than callus explant. An average of 57.33 and 92.00 daughter cormlets in all EMS treatments as compared to 47.67 and 57.67 daughter cormlets in control, obtained from callus and corm explants respectively, were transferred to the field. The maximum, average daughter cormlet weight was obtained in control (3.01 g, corm explant) followed by 0.1% EMS (2.8 g, corm explant). In general, the growth parameters showed decreasing trend with an increase in EMS concentration in both the explants. The present study has been a significant achievement in the sense that the first mutagenesis protocol for C. sativus has been standardized. [ABSTRACT FROM AUTHOR]

Phytochemical survey of the methanol extract of the dried aerial parts of Andrographis paniculata led to the isolation of major labdane diterpenes, namely 14-deoxy-11,12-didehydroandrographolide, andrographolide and neoandrographolide. Andrographolide was found to be the major phytoconstituent of the plant which was biologically active. For better physiochemical characteristics and bioefficacy, andrographolide is subjected to semi-synthetic modifications. However, presence of several free hydroxyl groups associated with this molecule make it quite polar and poorly soluble in many organic solvents and hence unsuitable for synthetic modifications. One way of resolving its solubility issue is to protect 1,3-diol quantitatively under mild reaction condition without effecting other functional groups. Reaction conditions were optimised using different solvent systems and catalysts towards this direction. X-ray structure of 3,19-isopropylidene-14-deoxy-11,12-didehydroandrographolide is being reported here for the first time. Isolated compounds and derivatives were confirmed by spectral analysis or X-ray data analysis. [ABSTRACT FROM AUTHOR]

The dried stigmas of Crocus sativus constitute the saffron, which is considered to be the costliest spice of the world. Saffron is valuable for its constituents, which are mainly apocarotenoids. In order to enhance the production of apocarotenoids, it is imperative to understand the regulation of apocarotenoid biosynthetic pathway. In C. sativus, although the pathway has been elucidated, the information regarding the regulation of the pathwaygenes is scanty. During the present investigation, the characterization of promoters regulating the expression of two important genes i.e. CsPSY and CsUGT was performed. We successfully cloned the promoters of both the genes, which were functionally characterized in Crocus sativus and Nicotiana tabaccum. In silico analysis of the promoters demonstrated the presence of several important cis regulatory elements responding tolight, hormonesand interaction with transcription factors (TFs). Further analysis suggested the regulation of CsPSY promoter by Abscisic acid (ABA) and that of CsUGT by Gibberellic acid (GA). In addition, we also observed ABA and GA mediated modulation in the expression of significant TFs and CsPSY and CsUGT transcripts. Overall, the study addresses issues related to regulation of key genes of apocarotenoid pathway in C.sativus. [ABSTRACT FROM AUTHOR]

Saffron is considered to be the costliest spice of the world. It has been regarded as highly valued medicinal plant in Ayurveda to treat various ailments. Over the past few years, considerable interest has developed in saffron because of its anticancer, antimutagenic, antioxidant and immunomodulatory properties. Saffron's colour, bitter taste and aroma are its three main and peculiar characteristics, which are conferred by three chemicals namely: crocin, picrocrocin and safranal, respectively. The present review focuses on recent research/progress made in saffron in the area of functional genomics and highlights the potential of several genes and transcription factors involved in carotenoid/apocarotenoid pathway and responsible for flavour and aroma of saffron. [ABSTRACT FROM AUTHOR]

Synthetic food colours pose a greater threat to humans and are responsible for causing various types of cancers and cardiovascular diseases. Purple black (PB) carrot anthocyanins extract showed different colours at different pH and hence can be used as alternatives to synthetic food colours. PB carrot anthocyanins show red colour in acids and greenish colour in basic solutions. The "colorimetric change" noted with the PB carrot extract is due to gain or loss of a proton (H+), by the pigments present in the extract mainly anthocyanins. This seemingly minor change is sufficient to alter the wavelengths at which the indicator absorbs and reflects light. This change in colour property of PB carrot anthocyanins can be exploited to detect real time food spoilage caused by various pathogens. We concluded that PB carrot is a rich source of dietary anthocyanins which can be used as food colorants and also as real time food spoilage indicators. [ABSTRACT FROM AUTHOR]

Three out of the eight Millennium Development Goals (MGDs); Eradication of poverty and hunger, reduction in child mortality and improving maternal health can be well addressed through food fortification initiatives. Half of the world population, particularly India relies on rice as the main food source being its main source of dietary energy. Since rice does not contain essentials vitamins like β-carotene, therefore Indian population that is totally dependent on rice are at high risk of developing vitamin A deficiency. In India the burden of Vitamin A deficiency (VAD) amounts to an annual loss of 2.3 million disability-adjusted life years (DALYs). Jammu and Kashmir stands fifth after Mizoram, Goa, Assam, Manipur and West Bengal in having the highest VAD cases in the age group of 10-14 years. The prevalence of biochemical VAD among under-five years children in India is 62%, which is among the highest in the world and accounts for 330000 deaths in India alone (WHO, 2009). Combating VAD among an estimated 12 million preschool children, it is claimed that government programs to provide vitamin A supplements to the affected children are expensive and complicated. And it is asserted that conventional, non-GM methods of introducing or enhancing β-carotene in other staple crops have been unsuccessful. Failure of Golden rice 1 and 2 in circumventing VAD is due to less amount of available pro-vitamin A. Assuming a β-carotene to vitamin A conversion rate of 1:1, 200 grams of "Golden Rice" per day will provide enough vitamin A. Contrarily some researchers work with a conversion rate of 2:1, which implies a daily intake of 500 grams of rice to attain the FAO/ WHO figure of 400μg for children between the ages of 1 and 3, thus no agreement on the amount of vitamin A that "Golden Rice 2" can in principle provide. So there is a need for the development of third generation Golden rice which produces even higher amount of β-carotene through Gene Amplification Technology (GAT). [ABSTRACT FROM AUTHOR]

Endophytes, which mostly include bacteria, fungi and actinomycetes, are the endosymbionts that reside asymptomatically in plants for at least a part of their life cycle. They have emerged as a valuable source of novel metabolites, industrially important enzymes and as stress relievers of host plant, but still many aspects of endophytic biology are unknown. Functions of individual endophytes are the result of their continuous and complex interactions with the host plant as well as other members of the host microbiome. Understanding plant microbiomes as a system allows analysis and integration of these complex interactions. Modern genomic studies involving metaomics and comparative studies can prove to be helpful in unraveling the gray areas of endophytism. A deeper knowledge of the mechanism of host infestation and role of endophytes could be exploited to improve the agricultural management in terms of plant growth promotion, biocontrol and bioremediation. Genome sequencing, comparative genomics, microarray, next gen sequencing, metagenomics, metatranscriptomics are some of the techniques that are being used or can be used to unravel plant-endophyte relationship. The modern techniques and approaches need to be explored to study endophytes and their putative role in host plant ecology. This review highlights "omics" tools that can be explored for understanding the role of endophytes in the plant microbiome. [ABSTRACT FROM AUTHOR]

B chromosomes are supernumerary dispensable parts of the karyotype which appear in some individuals of some populations in some species. Using advanced sequencing technology, we in silico characterized the high-copy DNA composition of Plantago lagopus with and without B chromosomes. The nuclear genome (2.46 pg/2C) was found to be relatively rich in repetitive sequences, with highly and moderately repeated elements making up 68% of the genome. Besides a centromere-specific marker, we identified a B-specific satellite and a repeat enriched in polymorphic A chromosome segments. The B-specific tandem repeat PLsatB originated from sequence amplification including 5S rDNA fragments. [ABSTRACT FROM AUTHOR]

Plantago ovata is an economically and medicinally important plant of the family Plantaginaceae. It is used extensively for the production of seed husk for its application in pharmaceutical, food and cosmetic industries. In the present study, the transcriptome of P. ovata ovary was sequenced using Illumina Genome Analyzer platform to characterize the mucilage biosynthesis pathway in the plant. De novo assembly was carried out using Oases followed by velvet. A total of 46,955 non-redundant transcripts (≥100 bp) using ~29 million high-quality paired end reads were generated. Functional categorization of these transcripts revealed the presence of several genes involved in various biological processes like metabolic pathways, mucilage biosynthesis, biosynthesis of secondary metabolites and antioxidants. In addition, simple sequence-repeat motifs, non-coding RNAs and transcription factors were also identified. Expression profiling of some genes involved in mucilage biosynthetic pathway was performed in different tissues of P. ovata using Real time PCR analysis. The study has resulted in a valuable resource for further studies on gene expression, genomics and functional genomics in P. ovata. [ABSTRACT FROM AUTHOR]

This review highlights the major differences between the regulation of two important pathways namely anthocyanin and carotenoid pathways, responsible for fruit color generation in Solanaceae mediated by transcription factors (TFs). The anthocyanin pathway is regulated by a common set of TFs (MYB, MYC and WD40) belonging to specific families of DNA-binding proteins.Their regulation is aimed at controlling the type and amount of pigments produced and the physiological conditions (like pH) at which they are finally stored. In the carotenoid pathway, the color diversity depends on the quantity of pigment produced and the point where the pathway is arrested. TFs in the latter case are accordingly found to influence the sequestration and degradation of these pigments, which determines their final concentration in the tissue. TFs (phytochrome interacting factors, MADS-BOX, HB-ZIP and B-ZIP) also regulate important rate-determining steps, which decide the direction in which the pathway proceeds and the point at which it is terminated. In the absence of a clear pattern of TF-mediated regulation, it is suggested that the carotenoid pathway ismore significantly influenced by other regulatorymethods which need to be explored. It is expected that common factors affecting these pathways are the ones acting much before the initiation of the biosynthesis of respective pigments. [ABSTRACT FROM AUTHOR]

The present study involves evaluation of antioxidant potential of Crocus sativus and its main constituents, safranal (SFN) and crocin (CRO), in bronchial epithelial cells, followed antiinflammatory potential of the active constituent safranal, in a murine model of asthma. To investigate the antioxidizing potential of Crocus sativus and its main constituents in bronchial epithelial cells, the stress was induced in these cells by a combination of different cytokines that resulted in an increase in nitric oxide production (NO), induced nitric oxide synthase (iNOS) levels, peroxynitrite ion generation, and cytochrome c release. Treatment with saffron and its constituents safranal and crocin resulted in a decrease of NO, iNOS levels, peroxynitrite ion generation, and prevented cytochrome c release. However, safranal significantly reduced oxidative stress in bronchial epithelial cells via iNOS reduction besides preventing apoptosis in these cells. In the murine model of asthma study, antiinflammatory role of safranal was characterized by increased airway hyper-responsiveness, airway cellular infiltration, and epithelial cell injury. Safranal pretreatment to these allergically inflamed mice lead to a significant decrease in airway hyper-responsiveness and airway cellular infiltration to the lungs. It also reduced iNOS production, bronchial epithelial cell apoptosis, and Th2 type cytokine production in the lungs. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We sought to identify risk factors for type 2 diabetes (T2D) in Jammu and Kashmir populations, India. A total of 424 diabetic and 226 non-diabetic subjects from Jammu, and 161 diabetic and 100 non-diabetic subjects from Kashmir were screened for various parameters including fasting blood glucose level, 2 hour glucose level, urea, creatinine, triglycerides, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein (VLDL-C), uric acid, systolic and diastolic blood pressure level. We found that subjects aged 40-49 years had the highest rate of diabetes, with family income playing not much of a role. Kashmiri migrants or populations with rapid cultural, environmental, social or lifestyle change along with reduced physical activity, obesity and unhealthy lifestyle (smoking and alcohol consumption) were found to have higher rates of diabetes. High blood glucose, triglycerides and low HDL-C levels were found to be contributing to disease outcome. High blood pressure also contributed to a higher risk of developing T2D. Our study supports earlier reports confirming the contribution of comfortable life style, Western dietary habits and rapid life style change along with many other factors to the prevalence of diabetes. This may contribute to the epidemic proportion of diabetes in Jammu and Kashmir. Early diagnosis and routine screening for undiagnosed diabetes in obese subjects and subjects with parental diabetes history is expected to decrease the burden of chronic diabetic complications worldwide. [ABSTRACT FROM AUTHOR]

Type 2 diabetes (T2D) is a syndrome of multiple metabolic disorders and is genetically heterogeneous. India comprises one of the largest global populations with highest number of reported type 2 diabetes cases. However, limited information about T2D associated loci is available for Indian populations. It is, therefore, pertinent to evaluate the previously associated candidates as well as identify novel genetic variations in Indian populations to understand the extent of genetic heterogeneity. We chose to do a cost effective high-throughput mass-array genotyping and studied the candidate gene variations associated with T2D in literature. In this case-control candidate genes association study, 91 SNPs from 55 candidate genes have been analyzed in three geographically independent population groups from India. We report the genetic variants in five candidate genes: TCF7L2, HHEX, ENPP1, IDE and FTO, are significantly associated (after Bonferroni correction, p<5.5E−04) with T2D susceptibility in combined population. Interestingly, SNP rs7903146 of the TCF7L2 gene passed the genome wide significance threshold (combined P value = 2.05E−08) in the studied populations. We also observed the association of rs7903146 with blood glucose (fasting and postprandial) levels, supporting the role of TCF7L2 gene in blood glucose homeostasis. Further, we noted that the moderate risk provided by the independently associated loci in combined population with Odds Ratio (OR)<1.38 increased to OR = 2.44, (95%CI = 1.67–3.59) when the risk providing genotypes of TCF7L2, HHEX, ENPP1 and FTO genes were combined, suggesting the importance of gene-gene interactions evaluation in complex disorders like T2D. [ABSTRACT FROM AUTHOR]

Plant Biotechnology involves manipulation of genetic material to develop better crops. Keeping in view the challenges being faced by humanity in terms of shortage of food and other resources, we need to continuously upgrade the genomic technologies and fine tune the existing methods. For efficient genetic transformation, Agrobacterium-mediated as well as direct delivery methods have been used successfully. However, these methods suffer from many disadvantages especially in terms of transfer of large genes, gene complexes and gene silencing. To overcome these problems, recently, some efforts have been made to develop genetic transformation systems based on engineered plant chromosomes called minichromosomes or plant artificial chromosomes. Two approaches namely, 'top-down' or 'bottom-up' have been used for minichromosomes. The former involves engineering of the existing chromosomes within a cell and the latter de novo assembling of chromosomes from the basic constituents. While some success has been achieved using these chromosomes as vectors for genetic transformation in maize, however, more studies are needed to extend this technology to crop plants. The present review attempts to trace the genesis of minichromosomes and discusses their potential of development into plant artificial chromosome vectors. The use of these vectors in genetic transformation will greatly ameliorate the food problem and help to achieve the UN Millennium development goals. [ABSTRACT FROM AUTHOR]

• Background and Aims The organization of rRNA genes in cultivated Plantago ovata Forsk. and several of its wild allies was analysed to gain insight into the phylogenetic relationships of these species in the genus which includes some 200 species.• Methods Specific primers were designed to amplify the internal transcribed spacer (ITS1 and ITS2) regions from seven Plantago species and the resulting fragments were cloned and sequenced. Similarly, using specific primers, the 5S rRNA genes from these species were amplified and subsequently cloned. Fluorescence in-situ hybridization (FISH) was used for physical mapping of 5S and 45S ribosomal RNA genes.• Results The ITS1 region is 19–29 bp longer than the ITS2 in different Plantago species. The 5S rRNA gene-repeating unit varies in length from 289 to 581 bp. Coding regions are highly conserved across species, but the non-transcribed spacers (NTS) do not match any database sequences. The clone from the cultivated species P. ovata was used for physical mapping of these genes by FISH. Four species have one FISH site while three have two FISH sites. In P. lanceolata and P. rhodosperma, the 5S and 45S (18S-5·8S-25S) sites are coupled.• Conclusions Characterization of 5S and 45S rRNA genes has indicated a possible origin of P. ovata, the only cultivated species of the genus and also the only species with x = 4, from a species belonging to subgenus Psyllium. Based on the studies reported here, P. ovata is closest to P. arenaria, although on the basis of other data the two species have been placed in different subgenera. FISH mapping can be used as an efficient tool to help determine phylogenetic relationships in the genus Plantago and show the interrelationship between P. lanceolata and P. lagopus. [ABSTRACT FROM AUTHOR]

The present study documents the de novo origin of an apparent B chromosome in Plantago lagopus. The origin was associated with mutation (aneuploidy), chromosome fragmentation, specific DNA sequence amplification, addition of telomeric repeats, and centromeric misdivision. It originated in the progeny of trisome 2, from the excision of 5S rDNA and 18S, 5.8S, 25S rDNA sequences located on chromosome 2, and within a few generations acquired many characteristics of an apparent B chromosome. The B chromosome has preferential transmission through the male (41%, P<0.025) and female gametes (42%, P<0.01) but does not affect plant phenotype. The B chromosome is completely heterochromatic, has a functional centromere and does not pair at meiosis with any A chromosomes of the standard complement. Fluorescence in situ hybridization analysis showed that it arose from massive amplification of 5S rDNA sequences, has 18S, 5.8S, 25S rDNA sequences at the ends of both arms and telomeric repeats at both termini. Ag-NOR-banding and determination of the maximum number of nucleoli in interphase cells indicate that the nucleolar organizer regions at the ends of both arms of the B chromosome are active in organizing nucleoli. RNA blot analysis showed that the 5S rDNA sequences are not transcribed. To our knowledge, this is the first report that fully documents one of the mechanisms by which B chromosomes may arise in nature. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

Carotenoids, the widespread and structurally diverse class of pigments, accumulate in the fruits of tomato plants in a tissue specific manner. The carotenoid biosynthetic pathway genes have been cloned and characterized in tomato and other plants, however, its regulation is still obscure. We collected and analyzed forty different accessions of tomato for the present study. HPLC analysis revealed differential accumulation of major carotenoids (lycopene and ß-carotene) in the ripe fruit tissue. In order to understand the underlying regulatory mechanisms in carotenoid biosynthesis and accumulation, we sequenced the cis-acting elements i.e. promoter, 5′ and 3′ untranslated regions of the carotenoid pathway genes, in all accessions, followed by their in silico validation. Major differences observed in the CAAT Box, Opaque-2 Box and L-box in the promoters of carotenoid isomerase and lycopene-beta cyclase genes, respectively, along with the variations in musashi binding element of 5′ untranslated regions of the carotenoid isomerase gene, suggest their differential role in regulating the carotenogenesis process in tomato. The binding sites for various transcription factors namely RIN, AGAMOUS, CRY, RAP2.2 and PIF1 on the promoters of important carotenoid pathway genes were predicted in silico. We propose that expression of carotenoid genes and also the formation of protein product in ripe tomato fruits, is regulated efficiently by the binding of these transcription factors at selected sites in the promoter region. Finally, the differential expression of the above-mentioned genes in different developmental tissues supports the possible involvement of promoters and untranslated regions in carotenoid biosynthesis and accumulation process. The present study has generated significant information concerning regulatory players involved in the carotenoid biosynthesis in tomato. [ABSTRACT FROM AUTHOR]

B chromosomes have been reported in many eukaryotic organisms. These chromosomes occur in addition to the standard complement of a species. Bs do not pair with any of the A chromosomes and they have generally been considered to be non-essential and genetically inert. However, due to tremendous advancements in the technologies, the molecular composition of B chromosomes has been determined. The sequencing data has revealed that B chromosomes have originated from A chromosomes and they are rich in repetitive elements. In our laboratory, a novel B chromosome was discovered in Plantago lagopus. Using molecular cytogenetic techniques, the B chromosome was found to be composed of ribosomal DNA sequences. However, further characterization of the chromosome using next generation sequencing (NGS) etc. revealed that the B chromosome is a mosaic of sequences derived from A chromosomes, 5S ribosomal DNA (rDNA), 45S rDNA, and various types of repetitive elements. The transmission of B chromosome through the female sex track did not follow the Mendelian principles. The chromosome was found to have drive due to which it was perpetuating in populations. The present paper attempts to summarize the information on nature, transmission, and origin of B chromosomes, particularly the current status of our knowledge in P. lagopus. [ABSTRACT FROM AUTHOR]

Plantago ovata is an important source of Psyllium (Isabgol), which swells upon contact with water forming mucilaginous mass, largely composed of arabinoxylans. In this study, we analyzed the expression pattern of arabinoxylan biosynthetic pathway genes at different stages of seed development in P. ovata. Besides, arabinoxylans were quantified at different stages of seed development in water extractable and water unextractable fractions. The expression analysis revealed 5-8 fold increase in the levels of expression of some genes involved in arabinoxylan biosynthetic pathway such as UDP-arabinopyranose mutase, UDP-xylosyltransferase 2 and xylan glucuronosyltransferase at 15 days after pollination stage in seed. The xylose and arabinose units were analyzed at different stages of seed development and also in water-soluble (cold water and hot water), alkali and ethanolic fractions. The concentration of xylose and arabinose units increased steadily after pollination. Overall, alkali extract had high concentration of xylose (0.70 ± 0.022 mg/g) and arabinose units (0.10 ± 0.01 mg/g) at 15 days after pollination stage. [ABSTRACT FROM AUTHOR]

Apple (Malus × domestica) is the third important fruit in terms of production and consumption worldwide. Apple scab caused by Venturia inaequalis is the most devastating disease of apple. In the apple-growing regions, many fungicides are sprayed to control the disease leading to increase in the production cost. Development of scab-resistant cultivars is the long-lasting solution to control the disease. In apples, more than 20 major scab resistance genes have been identified in various cultivars and few wild relatives. Of all these genes, Rvi6 derived from Malus floribunda has been most extensively used in different breeding programs. Gene for gene interactions of these resistance genes with the avirulence genes from V. inaequalis have been understood in many cases. QTL-based polygenic resistance has also been characterized in apple. Nucleotide Binding Site Leucine-Rich Repeats (NBS-LRR) have been identified from the apple genome and many of them have been characterized from the scab resistance region. Molecular markers associated with most of the major scab resistance genes have been identified and their position has been mapped on different linkage groups. Marker-assisted selection (MAS) can be helpful in speeding up and accurately identifying the scab-resistant parents and progeny. Pyramiding of several major resistance genes can be undertaken for more durable resistance against apple scab. The present paper reviews the Malus-Venturia pathosystem, current status of knowledge about scab resistance genes, and their application in breeding against apple scab. [ABSTRACT FROM AUTHOR]