Search

The effect of Bacillus subtilis in combination with salicylic (SA) and jasmonic (JA) acids on the activity of amylases, cellulases, proteases, and their inhibitors in potato leaves in connection with the development of resistance to Phytophthora infestans (Mont.) de Bary in conditions of moisture deficiency have been investigated. Plants grown from microtubers were treated with Bacillus subtilis suspension (108 cells/mL) and with a mixture of bacteria with SA (10−6 M), JA (10−7 M), and SA + JA and were then infected with P. infestans (107 spores/mL) and cultivated under drought. Treatment with B. subtilis bacteria, especially in combination with signaling molecules, contributed to a decrease in the degree of pathogen infestation on plants grown with a lack of moisture. Both salicylate and jasmonate signaling pathways play an important role in the regulation of hydrolase activity and the stimulation of plant resistance. The revealed differences in the degree of hydrolase inhibitors activation under the influence of B. subtilis bacteria and signal molecules suggest different paths to the formation of resistance to P. infestans in potato under drought conditions.

Potatoes (

OBJECTIVETo examine the relationship between intake of vegetables/potatoes and incident type 2 diabetes (T2D) and explore whether the relationship between vegetable intake and incident T2D is mediated by baseline BMI.RESEARCH DESIGN AND METHODSCross-sectional associations between exposure (baseline intake of total vegetables, vegetable subgroups, and potatoes) and baseline BMI were assessed by multivariable-adjusted linear regression models. Associations between exposure and incident T2D were examined by multivariable-adjusted Cox proportional hazards models. Mediation by BMI was quantified through exploration of natural direct and indirect effects.RESULTSAmong 54,793 participants in the Danish Diet, Cancer and Health cohort, 7,695 cases of T2D were recorded during a median follow-up of 16.3 years. Participants in the highest total vegetable intake quintile (median 319 g/day) had a 0.35 kg/m2 (95% CI −0.46, −0.24) lower BMI and a 21% (95% CI 16, 26%) lower risk of incident T2D after multivariable adjustment compared with those in the lowest quintile (median 67 g/day). Baseline BMI mediated ∼21% of the association between vegetable intake and incident T2D. Participants in the highest compared with the lowest (median 256 vs. 52 g/day) potato intake quintile had a 9% (95% CI 2, 16%) higher risk of T2D after multivariable adjustment, with no association found after accounting for underlying dietary pattern. Of the vegetable subclasses, higher intake of green leafy and cruciferous vegetables was associated with a statistically significantly lower risk of T2D.CONCLUSIONSThe findings provide evidence that a higher vegetable, but not potato, intake might help mitigate T2D risk, partly by reducing BMI. OBJECTIVE: To examine the relationship between intake of vegetables/potatoes and incident type 2 diabetes (T2D) and explore whether the relationship between vegetable intake and incident T2D is mediated by baseline BMI.RESEARCH DESIGN AND METHODS: Cross-sectional associations between exposure (baseline intake of total vegetables, vegetable subgroups, and potatoes) and baseline BMI were assessed by multivariable-adjusted linear regression models. Associations between exposure and incident T2D were examined by multivariable-adjusted Cox proportional hazards models. Mediation by BMI was quantified through exploration of natural direct and indirect effects.RESULTS: Among 54,793 participants in the Danish Diet, Cancer and Health cohort, 7,695 cases of T2D were recorded during a median follow-up of 16.3 years. Participants in the highest total vegetable intake quintile (median 319 g/day) had a 0.35 kg/m2 (95% CI -0.46, -0.24) lower BMI and a 21% (95% CI 16, 26%) lower risk of incident T2D after multivariable adjustment compared with those in the lowest quintile (median 67 g/day). Baseline BMI mediated ∼21% of the association between vegetable intake and incident T2D. Participants in the highest compared with the lowest (median 256 vs. 52 g/day) potato intake quintile had a 9% (95% CI 2, 16%) higher risk of T2D after multivariable adjustment, with no association found after accounting for underlying dietary pattern. Of the vegetable subclasses, higher intake of green leafy and cruciferous vegetables was associated with a statistically significantly lower risk of T2D.CONCLUSIONS: The findings provide evidence that a higher vegetable, but not potato, intake might help mitigate T2D risk, partly by reducing BMI.

In order to achieve preparation of cross-linked (CL) potato starch with the maximum degree of substitution, freezing pre-treatment (FS) in different modes as three days freezing (3D), two freezing-thawing cycles (3D + 3D) and 6 days freezing (6D) were conducted. Thereafter, native, frozen and cross-linked starches were characterized for morphological, structural and pasting properties as well as alkaline and intrinsic viscosity. Regarding obtained result, freezing pre-treatment as 3D + 3D was found to be an efficient method to achieve high level of cross-linking than native and other modes of freezing pre-treatments when exposed to POCl

Herein, a multistage induced electric field (IEF) combined with a continuous-flow reactor was utilized to assist the acid hydrolysis of corn, potato, and waxy corn starch for avoiding plate corrosion and heavy metal leakage. It was found that adding IEF stages was beneficial to improve the hydrolysis efficiency. Treating potato, corn, and waxy corn starch via continuous-flow IEF increased the reducing sugar contents up to 78.76 %, 57.86 %, and 66.18 %, respectively. The electrical conductivity of starch grew with the reaction stages, while starch yield demonstrated the opposite trend. Treated starch had higher solubility and gelatinization peak temperature than native starch, with the gelatinization enthalpy showing fluctuations. Meanwhile, the swelling power decreased as the number of IEF stages was increased. Observations of Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy indicated that the treated starch became more ordered, and crystalline regions were destroyed to various degrees with pores forming on particle surfaces. These variations could be attributed to acid hydrolysis and IEF.

Plant organelles are highly motile where their movement is significant for fast distribution of material around the cell, facilitation of the plant's ability to respond to abiotic and biotic signals, and for appropriate growth. Abiotic and biotic stresses are among the major factors limiting crop yields, and biological membranes are the first target of these stresses. Plants utilize adaptive mechanisms namely myosin to repair injured membranes following exposure to abiotic and biotic stresses.Due to the economic importance and cultivation of potato grown under abiotic and biotic stress prone areas, identification and characterization of myosin family members in potato were performed in the present research.To identify the myosin genes in potato, we performed genome-wide analysis of myosin genes in the S. tuberosum genome using the phytozome. All putative sequences were approved with the interproscan. Bioinformatics analysis was conducted using phylogenetic tree, gene structure, cis-regulatory elements, protein-protein interaction, and gene expression.The majority of the cell machinery contain actin cytoskeleton and myosins, where motility of organelles are dependent on them. Homology-based analysis was applied to determine seven myosin genes in the potato genome. The members of myosin could be categorized into two groups (XI and VIII). Some of myosin proteins were sub-cellularly located in the nucleus containing 71.5% of myosin proteins and other myosin proteins were localized in the mitochondria, plasma-membrane, and cytoplasm. Determination of co-expressed network, promoter analysis, and gene structure were also performed and gene expression pattern of each gene was surveyed. Number of introns in the gene family members varied from 1 to 39. Gene expression analysis demonstrated that StMyoXI-B and StMyoVIII-2 had the highest transcripts, induced by biotic and abiotic stresses in all three tissues of stem, root, and leaves, respectively. Overall, different cis-elements including abiotic and biotic responsive, hormonal responsive, light responsive, defense responsive elements were found in the myosin promoter sequences. Among the cis-elements, the MYB, G-box, ABRE, JA, and SA contributed the most in the plant growth and development, and in response to abiotic and biotic stress conditions.Our results showed that myosin genes can be utilized in breeding programs and genetic engineering of plants with the aim of increasing tolerance to abiotic and biotic stresses, especially to viral stresses such as PVY, PVX, PVA, PVS, high light, drought, cold and heat.

Greening is an undesirable trait that develops in potatoes upon light exposure. This condition lowers market value, increases tuber waste in retail stores, and consequently influences the price of product in the long run. When potatoes are subjected to artificial light, the amyloplast converts into chloroplast. Although the development of total glycoalkaloids (TGA) is independent of light, the greening induced by exposure of potato to artificial light is an indication of probable TGA acceleration, which could be present in a low amount initially. Several research studies on optimum postharvest factors (temperature, lighting condition, relative humidity, pretreatment, storage air composition, and packaging) have been carried out to avoid greening and TGA development. This current review highlights major postharvest factors and summarizes past research regarding cause of greening and TGA development in potatoes in retail stores. Additionally, it also portrays the potential solutions that could help mitigate this problem, ultimately reducing wastage and achieving food security.

The nutritional enhancement of potato plants (Solanum tuberosum L.,) is highly critical. As it is considered a worldwide basic vegetarian nutrition to maintain health. S. tuberosum is one of the foremost staples and the world's fourth-largest food crop. In advance, its need is increasing because of its high-industrial value and population blast. To improve both potato growth and behavior under harsh environmental conditions, we produced transgenic potato plants overexpressing either VvNHX (a sodium proton antiporter from Vitis vinifera), VvCLC (a chloride channel from Vitis vinifera), or both. Control and transgenic plants were grown in greenhouse and field under non-stressed conditions for 85 days in order to characterize their phenotype and evaluate their agronomical performance. To this aim, the evaluation of plant growth parameters, tuber yields and characteristics (calibers, eye number and color), the chemical composition of tubers, was conducted and compared between the different lines. The obtained results showed that transgenic plants displayed an improved growth (flowering precocity, gain of vigor and better vegetative growth) along with enhanced tuber yields and quality (increased protein and starch contents). Our findings provide then insight into the role played by the VvNHX antiport and the VvCLC channel and a greater understanding of the effect of their overexpression in potato plants.

Viroids are small, proteinless single-stranded circular RNAs. In plants, they can be transmitted via infected pollen and seeds. The effectiveness of viroid transmission through pollen depends on both the viroid and host species. It is, however, unclear whether viroid variant type or infection stage influences seed transmission through pollen. In the present study, we collected pollen from petunia infected with nine different variants of the potato spindle tuber viroid (PSTVd) at various stages after inoculation and used the material to pollinate healthy plants. Five and eight PSTVd variants were transmitted by pollen at 3 and 6 mpi respectively. All variants were pollen-transmissible at 9 mpi. The foregoing results indicated that seed transmission of PSTVd through pollen collected from infected donor plants may depend on the time elapsed since inoculation. For variant no. EU862231, however, the rate of seed transmission via pollen may depend on the pollen viroid titre. Nevertheless, there was no apparent correlation between the transmission rate and the pollen viroid titre in the U23058 or V01465 variant. Hence, the relationship between the viroid transmission rate and the pollen viroid titre may depend on the viroid variant type.

Isochoric impregnation was explored as a novel pressure-assisted infusion technique to fortify plant materials with bioactive compounds. Apple and potato cylinders were impregnated with a sucrose solution containing 4% ascorbic acid (AA) while freezing under isochoric conditions. Isochoric impregnation resulted in greater infusion of AA compared to infusion at atmospheric pressure, which demonstrated the feasibility of this impregnation technology. Processing temperatures (-3°C and -5°C) and processing times (1, 3, and 5 h) significantly affected the AA infusion. The AA content values ranged from 446 to 516 mg/100 g for apples and 322 to 831 mg/100 g for sweet potatoes under isochoric conditions. For both plant materials, isochoric impregnation at -3°C did not cause major changes in texture and microstructure of the biological tissues. These results indicated that isochoric impregnation of solid foods could be a feasible technology for infusion of bioactive compounds without significantly altering their matrix. PRACTICAL APPLICATION: The findings of this study showed that the use of isochoric impregnation as a fortification technique is a promising way to develop fresh-like and value-added products with improved nutrition during preservation at subfreezing temperatures.

To solve the problems of weak generalization of potato early and late blight recognition models in real complex scenarios, susceptibility to interference from crop varieties, colour characteristics, leaf spot shapes, disease cycles and environmental factors, and strong dependence on storage and computational resources, an improved YOLO v5 model (DA-ActNN-YOLOV5) is proposed to study potato diseases of different cycles in multiple regional scenarios. Thirteen data augmentation techniques were used to expand the data to improve model generalization and prevent overfitting; potato leaves were extracted by YOLO v5 image segmentation and labelled with LabelMe for building data samples; the component modules of the YOLO v5 network were replaced using model compression technology (ActNN) for potato disease detection when the device is low on memory. Based on this, the features extracted from all network layers are visualized, and the extraction of features from each network layer can be distinguished, from which an understanding of the feature learning behavior of the deep model can be obtained. The results show that in the scenario of multiple complex factors interacting, the identification accuracy of early and late potato blight in this study reached 99.81%. The introduced data augmentation technique improved the average accuracy by 9.22%. Compared with the uncompressed YOLO v5 model, the integrated ActNN runs more efficiently, the accuracy loss due to compressed parameters is less than 0.65%, and the time consumption does not exceed 30 min, which saves a lot of computational cost and time. In summary, this research method can accurately identify potato early and late blight in various scenarios.

Freezing stress is a major limiting factor in crop production. To increase frost-hardiness of crops via breeding, deciphering the genes conferring freezing-tolerance is vital. Potato cultivars (Solanum tuberosum) are generally freezing-sensitive, but some potato wild species are freezing-tolerant, including Solanum commersonii, Solanum malmeanum and Solanum acaule. However, the underlying molecular mechanisms conferring the freezing-tolerance to the wild species remain to be deciphered. In this study, five representative genotypes of the above-mentioned species with distinct freezing-tolerance were investigated. Comparative transcriptomics analysis showed that SaCBL1-like (calcineurin B-like protein) was upregulated substantially in all of the freezing-tolerant genotypes. Transgenic overexpression and known-down lines of SaCBL1-like were examined. SaCBL1-like was shown to confer freezing-tolerance without significantly impacting main agricultural traits. A functional mechanism analysis showed that SaCBL1-like increases the expression of the C-repeat binding factor-regulon as well as causes a prolonged higher expression of CBF1 after exposure to cold conditions. Furthermore, SaCBL1-like was found to only interact with SaCIPK3-1 (CBL-interacting protein kinase) among all apparent cold-responsive SaCIPKs. Our study identifies SaCBL1-like to play a vital role in conferring freezing tolerance in potato, which may provide a basis for a targeted potato breeding for frost-hardiness.

GF14 proteins are a family of conserved proteins involved in many cellular processes including transport, growth, metabolism, and stress response. However, only few reports are available regarding the 14-3-3 genes in potato. In this study, twelve 14-3-3 genes were detected in the potato genome. Based on their phylogenetic relationships, the StGF14 family members were categorized into two classes. Gene expression analysis demonstrated that StGF14h, StGF14a, and StGF14k had the highest gene expression, induced by abiotic and biotic stresses in all three tissues. The number of exons in 14-3-3 genes ranged from four to seven and most of these genes in the same subfamily had similar exon-intron patterns. The results of our study showed that the conserved motifs are similar in most of the proteins in each group. The intron-exon patterns and the composition of conserved motifs validated the 14-3-3 gene phylogenetic classification. According to the genome distribution results, 14-3-3 genes were located unevenly on the 12 Solanum tuberosum chromosomes. We find out 97 orthologous gene pairs between potato and Arabidopsis as well as 15 paralogous genes among potato genomes. Our results showed that GF-14 genes have an effective role in functional and molecular mechanisms in response to environmental stresses.

In this study, drying of grated potato in a hot air-assisted radio frequency system (HA-RF) and the associated effects on the final potato flour quality were studied. The drying behavior of the grated potatoes at different electrode distances (70-90 mm) and sample thickness (2-4 cm) was investigated. The safe drying (without burning tendency) of the maximum amount of sample (1000 g) in a reasonable drying time was carried out at 80 mm of electrode gap and 4 cm of sample thickness. HA-RF drying kinetics were studied and compared with hot air (HA) and radio frequency (RF) (without hot air) drying methods. HA-RF drying increased drying rate and shortened drying time by about 58% and 70% compared to HA and RF drying, respectively. The properties of the final potato flour obtained after HA-RF drying were also compared with those produced by RF, HA, and freeze drying. The flour obtained by HA-RF was superior to RF and HA dried samples with better retention of cellular microstructure and color. The drying method significantly affected the functional properties, thermal characteristics, pasting properties, and other characteristics of potato flours. PRACTICAL APPLICATION: HA-RF as an alternative drying technology was used for the first time to produce potato flour. The functional, thermal, and structural properties of the HA-RF dried product were compared with those dried by HA, RF, and freeze drying. The results of this study ensured very useful information for the use of potato flour obtained by different drying methods in the development of products with specific functional and rheological properties.

Potato, a cool-weather crop, emits volatile organic compounds (VOCs) which attract the specialist herbivore, Phthorimaea operculella, but also this herbivore's parasitic wasp, Trichogramma chilonis, an important biocontrol agent. What happens to this trophic system when heat stress challenges this agro-ecosystem? We studied how high temperature (HT) pre-treatments influence potato's VOC emissions and their subsequent effects on the preferences of insects, as evaluated in oviposition assays and Y-tube olfactometers. HT pre-stressed plants were less attractive to P. operculella adult moths, which were repelled by HT VOCs, but increased the recruitment of the parasitoid, T. chilonis, which were attracted. VOC emissions, including the most abundant constituent, ß-caryophyllene, were enhanced by HT treatments; some constituents elicited stronger behavioural responses than others. Transcripts of many genes in the biosynthetic pathways of these VOCs were significantly enhanced by HT treatment, suggesting increases in de novo biosynthesis. HT increased the plant's stomatal apertures, and exogenous applications of the hormone, ABA, known to suppress stomatal apertures, reduced leaf volatile emissions and affected the HT-altered plant attractions to both insects. From these results, we infer that HT stress affects this plant-insect interaction through its influence on VOC emissions, potentially decreasing herbivore ovipositions while increasing ovipositions of the parasitoid.

To develop an understanding mechanism to define responding of potatoes to R. solani, we analyzed the expression of ten novel candidate gene-markers using reverse-transcription-quantitative PCR (RT-qPCR) in resistant 'Savalan' and partially resistant 'Agria' in contrast to susceptible 'Sagita', and partially susceptible 'Pashandi'. In addition, oxidant-enzymatic-activity of catalase and superoxide-dismutase, as well as biomass-growth-parameters; shoot and root length, fresh and dry weight, and root volume were considered as complementary factors to the involving mechanism accordingly. Gene-markers up-regulated maximum up to 3.5-fold with the highest correlation, r = 0.939** following R. solani-inoculation, predominantly in resistant genotypes. Surprisingly, WRKY8-gene, basically resistant to late-blight-Phytophtora infestans was also up-regulated to 2.3-fold in resistant 'Savalan' followed by 'Agria'. Similar results with 3.1-fold were obtained on Osmotin-gene resistant to early-blight-Alternaria alternata. Enzymatic-activity of catalase with 1.6-fold and superoxide-dismutase, 6.8-fold also showed the highest level of activity in resistant genotypes, and had a high significant correlation, r = 773** and r = 0.881** with expression levels of related gene-markers respectively. Similarly, there were significant differences in biomass-growth-parameters, but with reductions in partially susceptible 'Sagita' and susceptible 'Pashandi'. Conclusively, S. tuberosum-R. solani interaction revealed that certain gene-markers can cover resistance to more than one disease simultaneously.

Potato (Solanum tuberosum L.) originated in the Andes and evolved its vegetative propagation strategy through short day-dependent tuber development. Herein, we present a high-quality, chromosome-scale reference genome sequence of a tetraploid potato cultivar. The total length of this genome assembly was 2.67 Gb, with scaffold N50 and contig N50 sizes of 46.24 and 2.19 Mb, respectively. In total, 1.69 Gb repetitive sequences were obtained through de novo annotation, and long terminal repeats were the main transposable elements. A total of 126 070 protein-coding genes were annotated, of which 125 077 (99.21%) were located on chromosomes. The 48 chromosomes were classified into four haplotypes. We annotated 31 506 homologous genes, including 5913 (18.77%) genes with four homologues, 11 103 (35.24%) with three homologues, 12 177 (38.65%) with two homologues and 2313 (7.34%) with one homologue. MLH3, MSH6/7 and RFC3, which are the genes involved in the mismatch repair pathway, were found to be significantly expanded in the tetraploid potato genome relative to the diploid potato genome. Genome-wide association analysis revealed that cytochrome P450, flavonoid synthesis, chalcone enzyme, glycosyl hydrolase and glycosyl transferase genes were significantly correlated with the flesh colours of potato tuber in 150 tetraploid potatoes. This study provides valuable insights into the highly heterozygous autotetraploid potato genome and may facilitate the development of tools for potato cultivar breeding and further studies on autotetraploid crops.

Calcium-dependent protein kinase (CDPK) is a Ca

Krompirjevo plesen povzroča oomiceta Phytophthora infestans, ki močno ogroža globalno pridelavo krompirja. Sorta Sárpo Mira velja za eno izmed bolj odpornih krompirjevih sort proti P. infestans, h kateri naj bi najbolj prispeval gen Rpi-Smira2/R8. Iz populacije F1 križancev, med petimi občutljivimi sortami in sorto Sárpo Mira, smo z genskimi markerji in efektorsko agroinfiltracijo izbrali deset genotipov R8, ki so vsebovali le gen Rpi-Smira2/R8, in jih izpostavili štirim različno agresivnim izolatom P. infestans, da pri preučili doprinos gena Rpi-Smira2/R8 k stopnji odpornosti proti krompirjevi plesni. Genotipe R8 smo, skupaj s pripadajočimi starševskimi sortami, inokulirali z izolati P. infestans na ravni tkivnih kultur in na ravni celih rastlin v rastlinjaku. Izmed testiranih genotipov R8 je genotip C571 izražal najvišjo stopnjo odpornosti, ki je bila po inokulaciji s tujimi izolati P. infestans primerljiva s starševsko sorto Sárpo Mira. V primeru genotipa C571 se je stopnja odpornosti ohranila tako pri inokulaciji tkivnih kultur kot tudi pri inokulaciji celih rastlin v rastlinjaku, medtem ko je bila sorta Sárpo Mira na ravni tkivnih kultur srednje odporna proti agresivnim tujim izolatom, na ravni celih rastlin v rastlinjaku pa je bila nanje popolnoma odporna. Z raziskavami v okviru doktorske disertacije smo tako pokazali, da gen Rpi-Smira2/R8 doprinese k stopnji odpornosti proti krompirjevi plesni, vendar je le-ta nižja v primerjavi s sorto Sárpo Mira in je pod vplivom genetskega ozadja. Late blight is caused by the oomycete Phytophthora infestans and is a major threat to the global potato production. Sárpo Mira cultivar is considered to be highly resistant to P. infestans, to which the Rpi-Smira2/R8 gene is said to contribute the most. From the population of F1 progeny, between five susceptible cultivars and Sárpo Mira cultivar, we selected ten R8 genotypes containing only the Rpi-Smira2/R8 gene using genetic markers and effector agroinfiltration, and exposed them to four P. infestans isolates differing in their aggressiveness, to evaluate the contribution of the Rpi-Smira2/R8 gene to the late blight resistance level. R8 genotypes, together with the corresponding parental varieties, were inoculated with P. infestans isolates as tissue cultures and as whole plants in the greenhouse. Among the tested R8 genotypes, the highest level of resistance was shown by genotype C571, which was comparable to the parental variety Sárpo Mira after inoculation with foreign isolates of P. infestans. In the case of genotype C571, the level of resistance was maintained both in tissue culture inoculation and in inoculation of whole plants in the greenhouse, while the Sárpo Mira cultivar was moderately resistant to aggressive foreign isolates at the level of tissue cultures and completely resistant as a whole plant in the greenhouse. With the research conducted in the scope of the doctoral dissertation, we have shown that the Rpi-Smira2/R8 gene contributes to late blight resistance, however the level of resistance is lower compared to the Sárpo Mira cultivar and under influence of the genetic background.

We applied a genomic in situ hybridization (GISH) to analyze the genomic constitution of and meiotic pairing in interspecific somatic hybrids, and in a wide subset of backcrossing derivatives (BC1–BC5), from three interspecific combinations involving the cultivated potato, Solanum tuberosum (AAAA genome), and three diploid (1 EBN) wild Mexican potato species (genome BB)—S. tarnii, S. pinnatisectum, and S. bulbocastanum. The theoretically expected genomic composition was detected in the somatic hybrids (AAAABB) and in the BC1 progeny (AAAAB), whereas in the subsequent BC2–BC4 generations, the partial loss of alien chromosomes was observed and almost all the BC5 genotypes showed a complete chromosome elimination of wild species. GISH revealed a homoeologous pairing between the chromosomes of the A- and the B-genomes in each of the hybrid progenies. Using GISH, we selected introgression lines with a single chromosome of the wild species in a potato genome background, as well as introgression lines with intergenomic recombinant chromosomes. Moreover, via molecular screening, BC hybrids with diagnostic markers for the R-genes conferring resistance to late blight disease and to the quarantine pest of the potato–Columbia root-knot nematode—were selected. The potential application of the results obtained for the planning of introgressive schemes directed to the breeding of advanced lines with multiple disease and pest resistance is discussed.

Izpostavljenost krompirja (Solanum tuberosum L.) biotskemu stresu povzroči spremenjeno izražanje na stres odzivnih genov, preko omogočanja ali zavrtja vezave prepisovalnih dejavnikov na cis-regulatorne elemente. V magistrskem delu smo analizirali promotor gena CPI8, da bi ugotovili, kateri cis-regulatorni element ali kombinacija več teh je ključna za odziv na jasmonsko kislino (JA), ki se tvori ob mehanski poškodbi tkiva in napadu koloradskega hrošča (Leptinotarsa decemlineata). Zaporedje različice tega promotorja iz rastline krompirja genotipa Désirée, pCPI8.De7, smo z verižno reakcijo s polimerazo (PCR) skrajšali na 3’- in 5’-koncu tako, da smo iz njega postopno izločali bioinformatsko predvidene cis-regulatorne elemente, odzivne na JA. Odseke pCPI8.De7 smo vstavili pred kodirajoče zaporedje gena za reporterski protein luciferazo. Nato smo prehodno transformirali rastline krompirja in tobaka (Nicotiana benthamiana Domin) in po tretiranju z JA in dodatku luciferina merili luminiscenco. Ugotovili smo, da krompir ni primeren za primerjavo aktivnosti odsekov pCPI8.De7. Z luciferaznimi testi na rastlinah tobaka smo odkrili ključen odsek pCPI8.De7 za odziv na JA, ki smo ga nato z mutagenim PCR dodatno skrajšali in vanj vnesli točkovne mutacije. Ugotovili smo, da je za odziv na JA najverjetneje ključna kombinacija vezavnih mest za prepisovalna dejavnika VIP1 in NAC078 ter še nepoznanega cis-regulatornega elementa. Te elemente bi lahko uporabili za razvoj gensko zapisanega biosenzorja za JA, kar bi omogočilo boljše razumevanje mehanizmov obrambe na stres pri krompirju. Exposure of potato (Solanum tuberosum L.) to biotic stress results in altered expression of genes that respond to stress by activating or deactivating binding of transcription factors to cis-regulatory elements. In this master's thesis, we analysed the CPI8 gene promoter to determine a cis-regulatory element, or a combination of several elements, crucial for the response to jasmonic acid (JA), which is synthesized during stresses such as mechanical tissue damage and Colorado potato beetle infestation (Leptinotarsa decemlineata). First, we truncated the sequence of the promoter variant from potato genotype Désirée, pCPI8.De7, on its 3’ and 5’ end using polymerase chain reaction (PCR) to gradually exclude predicted JA responsive cis-regulatory elements. We fused the truncated versions of pCPI8.De7 to the coding sequence of the reporter protein luciferase. We then performed transient transformation of potato and tobacco (Nicotiana benthamiana Domin) plants and measured luminescence after addition of luciferin and JA. Results showed that potato is not suitable for such an assay. On the other hand, using luciferase assays on tobacco, we identified a section in the CPI8.De7 promoter that is crucial for the response to JA. Using mutagenic PCR, we further truncated this section and introduced several point mutations and discovered that most likely, the combination of binding sites for the transcription factors VIP1 and NAC078 and a yet unknown cis-regulatory element is indispensable for the response of pCPI8.De7 to JA. These elements could be used to develop a genetically encoded biosensor for JA that would enable a better understanding of stress defense mechanisms in potato.

ilustraciones, fotografías En esta investigación inicialmente se realizó un estudio de bioprospección para seleccionar hongos rizosféricos de cultivos de papa, hongos promisorios para la síntesis de AgNp´s con acción antibacterial frente a Pectobacterium carotovorum, agente fitopatógeno de papa de difícil manejo por técnicas convencionales. Se aislaron cinco hongos de las especies Penicillium simplicissimum, Aspergillus niger y Fusarium oxysporum que produjeron AgNp´s esféricas de tamaños entre 15 y 45 nm, las cuales presentaron acción antibacterial frente al fitopatógeno. Empleándose a Fusarium oxysporum se encontró que al usar una solución de AgNO3 3mM, pH de 10, y 27 °C/24 h se obtiene el mayor rendimiento en la síntesis de AgNp´s. Posteriormente, estas nanopartículas fueron caracterizadas por TEM, FTIR, XRD, DLS. PI y potencial Z, tras lo cual su poder antibacterial frente al fitopatógeno Pectobacterium carotovorum fue estudiado, encontrándose zonas de inhibición de crecimiento de hasta 11,3 mm de diámetro cuando se emplea una dosis de 100 ppm y una MIC de 25 y 50 ppm, determinada por micro y macrodilución respectivamente. También se realizaron estudios a nivel del sustrato vegetal, evidenciándose un efecto protector sobre el tubérculo cuando se aplica una dosis de 100 ppm de AgNp´s sobre el tejido a manera de tratamiento preventivo. Posteriormente y para limitar la absorción de las nanopartículas en el tubérculo se realizaron pruebas de inmovilización de las AgNp´s sobre fibras de algodón quirúrgico por dos metodologías (cationización y reducción bioquímica in situ), obteniéndose dos tipos de fibras denominadas A-AgNp´s-C y A-AgNp´s-RBi. Fibras que mostraron zonas de inhibición de crecimiento del Pectobacterium carotovorum, con una disminución en los recuentos bacterianos a las 24 horas e inhibición de crecimiento a las 48 horas. Donde las pruebas de reuso de estas fibras con nanopartículas mostraron que los dos tipos fibras pueden tener hasta tres usos sucesivos sin perder su efectividad, independientemente del método de modificación empleado. Adicionalmente, es importante resaltar que las pruebas de retención de las AgNp´s indicaron que estas permanecen adheridas a las fibras A-AgNp´s-C y a las fibras A-AgNp´s-RBi después de dos y tres lavados sucesivos, respectivamente. Finalmente, las AgNp´s biosintetizadas se adhirieron a fibras de fique por cationización con el objetivo de obtener sacos antibacteriales de 10 x 12 cm, los cuales en pruebas in vivo presentaron tan solo un 7,8 % de afectación, mientras que tubérculos almacenados en un saco tradicional tuvieron una afectación del 25%. Por lo tanto, el empleo de hongos rizosféricos para la síntesis de AgNp´s con acción nanopesticida frente al fitopatógeno P. carotovorum y su inmovilización en fibras naturales, permitirá el desarrollo de una aplicación nanobiotecnológica en el campo de embalajes para el almacenamiento de papa, con posibilidades de escalamiento, lo que aunará en la implementación de prácticas de agricultura de precisión. (Texto tomado de la fuente) In this research, a bioprospecting study was initially carried out to select rhizospheric fungi from potato crops, promising fungi for the synthesis of AgNPs with an antibacterial action against Pectobacterium carotovorum, a potato phytopathogenic agent that is difficult to manage by conventional techniques. Five fungi of Penicillium simplicissimum, Aspergillus niger, and Fusarium oxysporum that produce spherical AgNPs between 15 and 45 nm in size were isolated and showed antibacterial action against the phytopathogen. Using Fusarium oxysporum, it was found that using a solution of AgNO3 3mM, pH 10, and 27 °C/24 h obtained the highest yield in AgNPs synthesis. Subsequently, these nanoparticles were characterized by TEM, FTIR, XRD, DLS, PI and Z-potential, after which their antibacterial power against the phytopathogen Pectobacterium carotovorum was studied, finding growth inhibition zones up to 11.3 mm in diameter when using a dose of 100 ppm and a MIC of 25 and 50 ppm, determined by micro and macrodilution, respectively. Studies were also carried out at the plant substrate level, showing a protective effect on the tuber when a dose of 100 ppm of AgNPs was applied to the tissue as a preventive treatment. Subsequently, and to limit the absorption of the nanoparticles in the tubercle, immobilization tests of AgNPs on surgical cotton fibers were carried out by two methodologies (cationization and in situ biochemical reduction), obtaining two types of fibers called A-AgNPs-C and A-AgNPs-RBi. These fibers showed growth inhibition zones of Pectobacterium carotovorum, with a decrease in bacterial counts at 24 hours and growth inhibition at 48 hours. The reuse tests of these fibers with nanoparticles showed that the two types of fibers could have up to three successive uses without losing their effectiveness, regardless of the modification method used. Additionally, it is important to highlight that the retention tests of the AgNPs indicated that they remain attached to the A-AgNPs-C and A-AgNPs-RBi fibers after two and three successive washes, respectively. Finally, the biosynthesized AgNPs were adhered to fique fibers by cationization to obtain antibacterial 10 x 12 cm sacks, which in in vivo tests showed only 7.8% of affectation, while tubers stored in a traditional sack had an affectation of 25%. The use of rhizospheric fungi for the synthesis of AgNPs with nanopesticidal action against the phytopathogen P. carotovorum and their immobilization in natural fibers will allow the development of a nanobiotechnological application in the field of potato storage packaging, with the possibility of scaling up, which will contribute to the implementation of precision agriculture practices. Gobernación de Boyacá mediante la convocatoria 733 de 2015. Formación de capital humano de alto nivel. Doctorado Nacional. Doctorado Doctor en Biotecnología Bioprocesos

The genetic basis of the resistance of potatoes to Phytophthora infestans is well-studied. Plant resistance to P. infestans is genetically controlled, and secondary metabolites play a role, but the metabolites themselves (e.g., phenylpropanoids) are poorly understood. This study aimed to characterize the effects of two P. infestans isolates and host resistance on secondary metabolite expression in potato plants. To do this, the phenylpropanoid pathway, chlorogenic acid, flavonoids, salicylic acid and jasmonic acid elicitors were characterized. The late blight-susceptible potato cultivar (Jutlandia) responded to both isolates with changes in the levels of compounds in the early phenylpropanoid pathway, whereas the response of the resistant cultivar (Toluca) occurred later in the pathway and was more marked in the case of the A2 mating-type isolate. The results reveal important differences in the role of secondary metabolism in resistance to P. infestans and suggest that different phenylpropanoids are affected depending on the isolate and the host's susceptibility to P. infestans.

The recovery of valuable bioactive compounds from the main underutilised by-products of the food industry is one of the greatest challenges to be addressed in circular economy. Potato peels are the largest waste generated during potato processing. However, they could be a potential source of valuable bioactive compounds, such as polyphenols, that can be reused as natural antioxidants. Currently, environmentally benign enabling technologies and new types of non-toxic organic solvents for the extraction of bioactive compounds may dramatically improve the sustainability of these processes. This paper focuses on the potential inherent in the valorisation of violet potato peels (VPPs) by recovering antioxidants using natural deep eutectic solvents (NaDES) under ultrasound (US)- and microwave (MW)-assisted extraction. Both the enabling technologies provided performances that were superior to those of conventional extractions in terms of antioxidant activity determined by the DPPH· (2,2-diphenyl-1-picrylhydrazyl) assay. In particular, the most promising approach using NaDES is proven to be the acoustic cavitation with a Trolox eq. of 1874.0 mmolTE/gExtr (40 °C, 500 W, 30 min), vs. the 510.1 mmolTE/gExtr of hydroalcoholic extraction (80 °C, 4 h). The shelf-life of both hydroalcoholic and NaDES-VPPs extracts have been assessed over a period of 24 months, and found that NaDES granted a 5.6-fold shelf-life extension. Finally, the antiproliferative activity of both hydroalcoholic and NaDES-VPPs extracts was evaluated in vitro using the MTS assay on human tumour Caco-2 cells and normal human keratinocyte cells (HaCaT). In particular, NaDES-VPPs extracts exhibited a significantly more pronounced antiproliferative activity compared to the ethanolic extracts without a noteworthy difference between effects on the two cell lines.

Potato tuber skin is a protective corky tissue consisting of suberized phellem cells. Smooth-skinned varieties are characterized by a clean, shiny appearance compared to the darker hue of russeted potatoes. The rough skin of russeted cultivars is a desired, genetically inherited characteristic; however, unwanted russeting of smooth-skinned cultivars often occurs under suboptimal growth conditions. The involvement of epigenetic modifiers in regulating the smooth skin russeting disorder was tested. We used smooth-skin commercial cultivars with and without the russeting disorder and three lines from a breeding population segregating for russeting. Anatomically, the russet skin showed similar characteristics, whether the cause was environmentally triggered or genetically determined. The old outer layers of the corky phellem remain attached to the newly formed phellem layers instead of being sloughed off. Global DNA methylation analysis indicated a significant reduction in the percentage of 5-methylcytosine in mature vs. immature skin and russet vs. smooth skin. This was true for both the smooth-skin commercial cultivars and the russeted lines. The expression level of selected DNA methyltransferases was reduced in accordance. DNA demethylase expression did not change between the skin types and age. Hence, the reduced DNA methylation in mature and russet skin is more likely to be achieved through passive DNA demethylation and loss of methyltransferase activity.

The main reserve polysaccharide of plants—starch—is undoubtedly important for humans. One of the main sources of starch is the potato tuber, which is able to preserve starch for a long time during the so-called dormancy period. However, accumulated data show that this dormancy is only relative, which raises the question of the possibility of some kind of starch restructuring during dormancy periods. Here, the effect of long-term periods of tuber rest (at 2–4 °C) on main parameters of starches of potato tubers grown in vivo or in vitro were studied. Along with non-transgenic potatoes, Arabidopsis phytochrome B (AtPHYB) transformants were investigated. Distinct changes in starch micro and macro structures—an increase in proportion of amorphous lamellae and of large-sized and irregular-shaped granules, as well as shifts in thickness of the crystalline lamellae—were detected. The degree of such alterations, more pronounced in AtPHYB-transgenic tubers, increased with the longevity of tuber dormancy. By contrast, the polymorphic crystalline structure (B-type) of starch remained unchanged regardless of dormancy duration. Collectively, our data support the hypothesis that potato starch remains metabolically and structurally labile during the entire tuber life including the dormancy period. The revealed starch remodeling may be considered a process of tuber preadaptation to the upcoming sprouting stage.

Global climate change will result in increasingly arid weather that will have a significant impact on agriculture. The occurrence dynamics of plants, phytophagous insects and their natural enemies under drought conditions have attracted much attention. The consequences could be useful for controlling insect herbivores. Leptinotarsa decemlineata (Say) is one of the most important pests of potato, and causes serious damage to potato production. Arma chinensis (Fallou) is a parasitoid of L. decemlineata. However, how drought will affect tritrophic interactions between potato and these insects remains unknown.In this experiment, L. decemlineata and A. chinensis were released onto potato plants under water stress. Thereafter, plant height, stem diameter and yield of potato, growth and reproduction of L. decemlineata, and the longevity of A. chinensis adults were periodically recorded. The results showed that drought had crucial effects on height, stem diameter and yield of potato (p 0.05); it also had a significant impact on pre-oviposition period, oviposition days, fecundity and life table parameters in L. decemlineata (p 0.05). Moreover, drought significantly reduced the longevity (p 0.05) and survival rate of A. chinensis adults. The longevity of adult A. chinensis was only 29.00 ± 3.00 days and the harvest rate of L. decemlineata adults was only 1.42% ± 0.07% under drought treatment.In this experiment, we evaluate the bottom-up effects of drought on tritrophic interactions involving potato, L. decemlineata and A. chinensis, and discuss the implications of the findings for integrated pest management programs involving the pest. Promising future research directions are proposed. © 2022 Society of Chemical Industry.

Terpene synthases (TPSs) have diverse biological functions in plants. Though the roles of TPSs in herbivore defense are well established in many plant species, their role in bacterial defense has been scarce and is emerging. Through functional genomics, here we report the in planta role of potato (Solanum tuberosum) terpene synthase (StTPS18) in bacterial defense. Expression of StTPS18 was highest in leaves and was induced in response to Pseudomonas syringae and methyl jasmonate treatments. The recombinant StTPS18 exhibited bona fide (E,E)-farnesol synthase activity forming a sesquiterpenoid, (E,E)-farnesol as the sole product, utilising (E,E)-farnesyl diphosphate (FPP). Subcellular localization of GFP fusion protein revealed that StTPS18 is localized to the cytosol. Silencing and overexpression of StTPS18 in potato resulted in reduced and enhanced tolerance, respectively, to bacterial pathogens P. syringae and Ralstonia solanacearum. Bacterial growth assay using medium containing (E,E)-farnesol significantly inhibited P. syringae growth. Moreover, StTPS18 overexpressing transgenic potato and Nicotiana tabacum leaves, and (E,E)-farnesol and P. syringae infiltrated potato leaves exhibited elevated expression of sterol pathway and members of pathogenesis-related genes with enhanced phytosterol accumulation. Interestingly, enhanced phytosterols in

Texture-modified foods and thickened fluids play a major role in clinical treatment for individuals who suffer from swallowing difficulties (known as dysphagia). International Dysphagia Diet Standardization Initiative (IDDSI) developed a standardized terminology and description for texture-modified foods and thickened fluids to allow dysphagia patients to receive the correct consistency of food/drink. While the IDDSI framework provides a consistent texture description (Levels 0-7) and is widely accepted as an international standard, testing and assessment of IDDSI texture level are qualitative in nature and subjective in manner. These methods were proposed primarily for use by frontline carers, but are not most ideal for industrial purposes of quality control of such products. Therefore, the main aim of this work was to develop a quantitative instrumental method that best describes IDDSI levels as an objective framework. A set of test samples, including commercially available instant mashed potato, baby rice cereal, and cooked potato cubes of varying texture, were prepared. Two IDDSI measuring techniques, fork pressure test and spoon tilt test, were used to evaluate texture grades of these samples. Puncture and compression tests based on texture analyzer were used to assess cohesiveness, adhesiveness, firmness, and hardness for each food category (Levels 4-7). Thresholds of cohesiveness and adhesiveness, as well as bands of acceptable firmness and hardness for each food category were clearly identified and are proposed as objective complements to the IDDSI framework.

Mitochondrial iron transporter (MIT) genes are essential for mitochondrial acquisition/import of iron and vital to proper functioning of mitochondria. Unlike other organisms, research on the MITs in plants is limited. The present study provides comparative bioinformatics assays for the potato MIT gene (StMIT) as well as gene expression analyses. The phylogenetic analyses revealed monocots-dicot divergence in MIT proteins and it was also found clade specific motif diversity. In addition, docking analyses indicated that Asp172 and Gly100 residues to be identified as the closest residues binding to ferrous iron. The percentage of structure overlap of the StMIT 3D protein model with Arabidopsis, maize and rice MIT proteins was found between 80.18% and 85.71%. The transcript analyses exhibited that the expression of StMIT was triggered under drought and salinity stresses. The findings of the present study would provide valuable leads for further studies targeting specifically the MIT gene and generally the plant iron metabolism.

Potato (Solanum tuberosum L.) is the world’s most important non-cereal food crop, and the vast majority of commercially grown cultivars are highly heterozygous tetraploids. Advances in diploid hybrid breeding based on true seeds have the potential to revolutionize future potato breeding and production1–4. So far, relatively few studies have examined the genome evolution and diversity of wild and cultivated landrace potatoes, which limits the application of their diversity in potato breeding. Here we assemble 44 high-quality diploid potato genomes from 24 wild and 20 cultivated accessions that are representative of Solanum section Petota, the tuber-bearing clade, as well as 2 genomes from the neighbouring section, Etuberosum. Extensive discordance of phylogenomic relationships suggests the complexity of potato evolution. We find that the potato genome substantially expanded its repertoire of disease-resistance genes when compared with closely related seed-propagated solanaceous crops, indicative of the effect of tuber-based propagation strategies on the evolution of the potato genome. We discover a transcription factor that determines tuber identity and interacts with the mobile tuberization inductive signal SP6A. We also identify 561,433 high-confidence structural variants and construct a map of large inversions, which provides insights for improving inbred lines and precluding potential linkage drag, as exemplified by a 5.8-Mb inversion that is associated with carotenoid content in tubers. This study will accelerate hybrid potato breeding and enrich our understanding of the evolution and biology of potato as a global staple food crop.

Lately, there has been an increasing interest in using plant-derived proteins for wine phenolic fining. Proteins extracted from cereals, potatoes, and legumes have been proposed as effective fining agents, but only those from pea, wheat, and potatoes have been approved for their use in wine. This work aimed at determining the fining ability of quinoa (Chenopodium quinoa Willd.) protein extracts (QP), compared to commercial fining agents, on red wines.The trials compared the performance of QP (30 and 50 g/hL), two potato protein extracts and gelatin, at two different contact times (48 and 96 h), using Petit Verdot, Malbec, and Cabernet Sauvignon wines. Turbidity, total phenolics, precipitable tannins, catechins, and color characteristics were determined. QP reduced the turbidity of all wines in a similar way to commercial fining agents. Both doses of QP significantly reduced tannins and other phenolic measures, including color intensity reductions, in a similar way to commercial fining agents.QP behaved as an effective fining agent that deserves further studies in order to improve its performance and advance its characterization. © 2022 Society of Chemical Industry.

Zebra chip disease (ZC), associated with the plant pathogenic bacterium 'Candidatus Liberibacter solanacearum' (psyllaurous) (CLso), is a major threat to global potato production. In addition to yield loss, CLso infection causes discoloration in the tubers, rendering them unmarketable. CLso is transmitted by the potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae). ZC is managed by prophylactic insecticide applications to control the vector, which is costly and carries environmental and human health risks. Given the expense, difficulty, and unsustainability of managing vector-borne diseases with insecticides, identifying sources of resistance to CLso and developing varieties that are resistant or tolerant to CLso and/or potato psyllids has become a major goal of breeding efforts. These efforts include field and laboratory evaluations of noncultivated germplasm and cultivars, studies of tubers in cold storage, detailed quantifications of biochemical responses to infection with CLso, possible mechanisms underlying insect resistance, and traditional examination of potato quality following infections. This review provides a brief history of ZC and potato psyllid, a summary of currently available tools to manage ZC, and a comprehensive review of breeding efforts for ZC and potato psyllid management within the greater context of Integrated Pest Management (IPM) strategies. © 2022 Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Isotope-labeled four polycyclic aromatic hydrocarbons (PAH4-d12) were applied to study the migration and distribution of PAH4 in oil to French fries during frying. The results showed that the mobilities of PAH4-d12 showed a downtrend within 0-6 h and then an uptrend, and PAH4-d12 were mainly distributed in the crust of the French fries, especially five-ring PAHs-d12. The correlation analysis showed that PAH4-d12 migration was mainly caused by oil absorption of French fries. The low fluidity of the oil slowed down the PAH4-d12 migration, which was accelerated as the total polar component increased (higher than 15-20%). Additionally, higher frying temperature enhanced the crust ratio and porous structure of French fries, which explained the abundant five-ring PAHs-d12 distributed in the crust. This study provided references for optimizing the frying parameters: the exposure of PAH4 in French fries to humans can be reduced by controlling the oil quality and weakening the crust of the French fries.

The addition of potato to wheat flour extends the nutritional values of bread. However, the adverse effects mediated by high dietary fiber in potato flour could affect the formation of gluten matrix. The water dynamics and distribution determined by the Low field nuclear magnetic resonance (LF-NMR) demonstrated a competitive water binding of dietary fiber, resulting in the partial dehydration and conformational changes of gluten protein complexes. Besides, the microstructure of the dough characterized by Scanning electron microscope (SEM) suggested that the insoluble cellulose could block the continuity of gluten from the spatial position, thereby negative affecting the mechanical properties of the dough. In our study, addition of cellulase and/or pectinase apparently mitigated the gluten aggregation and dehydration, contributing to the formation and the continuity of the three-dimensional gluten network. As a consequence, the specific volume of the bread was increased by 40.2%, and the hardness was reduced by 64.48%.

El reconocimiento genético del cultivo de las papas (Solanum tuberosum L.) en las comunidades andinas merideñas, donde su producción constituye uno de los principales rubros agrícolas, es fundamental para asegurar la preservación de las variedades locales, constituidas por especies silvestres, nativas y sin nombres. En el estudio presentamos los resultados del análisis morfológico, polínico y molecular de 29 muestras de germoplasma de papa de diferentes localidades de los Andes merideños que se encuentran resguardados en el Campo Experimental del INIA- Mucuchíes, Venezuela The genetic recognition of the cultivation of potatoes (Solanum tuberosum L.) in the Andean communities of Merida, where their production constitutes one of the main agricultural items, is essential to ensure the preservation of local varieties, composed of wild, native and unnamed species. In the study we present the results of the morphological, pollen, and molecular analysis of 29 potato germplasm samples from different localities in the Meridian Andes that are sheltered in the INIA-Mucuchíes Experimental Field, Venezuela. 129-169 gordonesgladys@gmail.com gonzalezplourdes23@gmail.com marthaosorio2013@gmail.com lmeneses@ula.ve Semestral https://saber.ula.ve/boletin_antropologico/

Ralstonia solanacearum is the causative agent of bacterial wilt of potato and other vegetable crops. Contaminated irrigation water contributes to the dissemination of this pathogen but the exact concentration or biological threshold to cause an infection is unknown. In two greenhouse experiments, potted potato plants (Solanum tuberosum) were exposed to a single irrigation with 50 mL water (non-invasive soil-soak inoculation) containing no or 102 - 108 CFU/mL R. solanacearum. The disease response of two cultivars, Kondor and HB, were compared. Disease development was monitored over a three-month period after which stems, roots and tubers of asymptomatic plants were analyzed for latent infections. First wilting symptoms were observed 15 days post inoculation in a plant inoculated with 5x109 CFU and a mean disease index was used to monitor disease development over time. An inoculum of 5x105 CFU per pot (1.3x102 CFU/g soil) was the minimum dose required to cause wilting symptoms, while one latent infection was detected at the lowest dose of 5x102 CFU per pot (0.13 CFU/g). In a second set of experiments, stem-inoculated potato plants grown in vitro were used to investigate the dose-response relationship under optimal conditions for pathogen growth and disease development. Plants were inoculated with doses between 0.5 and 5x105 CFU/plant which resulted in visible symptoms at all doses. The results led to a dose-response model describing the relationship between R. solanacearum exposure and probability of infection or illness of potato plants. Cultivar Kondor was more susceptible to brown-rot infections than HB in greenhouse experiments while there was no significant difference between the dose-response models of both cultivars in in vitro experiments. The ED50 for infection of cv Kondor was 1.1x107 CFU. Results can be used in management strategies aimed to reduce or eliminate the risk of bacterial wilt infection when using treated water in irrigation.

Ralstonia solanacearum is the causative agent of bacterial wilt of potato and other vegetable crops. Contaminated irrigation water contributes to the dissemination of this pathogen but the exact concentration or biological threshold to cause an infection is unknown. In two greenhouse experiments, potted potato plants (Solanum tuberosum) were exposed to a single irrigation with 50 mL water (non-invasive soil-soak inoculation) containing no or 102 - 108 CFU/mL R. solanacearum. The disease response of two cultivars, Kondor and HB, were compared. Disease development was monitored over a three-month period after which stems, roots and tubers of asymptomatic plants were analyzed for latent infections. First wilting symptoms were observed 15 days post inoculation in a plant inoculated with 5x109 CFU and a mean disease index was used to monitor disease development over time. An inoculum of 5x105 CFU per pot (1.3x102 CFU/g soil) was the minimum dose required to cause wilting symptoms, while one latent infection was detected at the lowest dose of 5x102 CFU per pot (0.13 CFU/g). In a second set of experiments, stem-inoculated potato plants grown in vitro were used to investigate the dose-response relationship under optimal conditions for pathogen growth and disease development. Plants were inoculated with doses between 0.5 and 5x105 CFU/plant which resulted in visible symptoms at all doses. The results led to a dose-response model describing the relationship between R. solanacearum exposure and probability of infection or illness of potato plants. Cultivar Kondor was more susceptible to brown-rot infections than HB in greenhouse experiments while there was no significant difference between the dose-response models of both cultivars in in vitro experiments. The ED50 for infection of cv Kondor was 1.1x107 CFU. Results can be used in management strategies aimed to reduce or eliminate the risk of bacterial wilt infection when using treated water in irrigation.

Stem canker and black scurf of potato (Solanum tuberosum L.) caused by Rhizoctonia solani Kühn are important and epidemic diseases in potato-growing regions worldwide, including Iran. In this study, 120 isolates were retrieved from infected stem canker from six potato- growing regions in Iran (Isfahan, Ardebil, Fars, Hamedan, Kurdestan and Kerman). Out of these, 30 isolates were selected as representatives for genetic and virulence analysis. The isolates were analyzed by one sequence analyzes of the ITS-rDNA region, random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR), as well as virulence studies. Based on sequence analysis of the ITS-rDNA region, all 30 isolates were assigned to the anastomosis group (AG) and all were assigned to AG-3 PT. Cluster analysis using the unweighted pair group method with the arithmetic averages (UPGMA) method for both RAPD and ISSR markers revealed that they were divided into three main groups, with no correlation to geographical regions of the isolates. Pathogenicity tests showed that all isolates were pathogenic on potato cv. Agria; however, virulence variability was observed among the isolates. The grouping based on RAPD analysis and virulence variability was not correlated.

A study was undertaken to investigate the relationship between the factors (initial height, tuber mass, tuber temperature and impact material) and the impact characteristic variables (impact velocity and bruise volume) as determined by pendulum impact test-rig. It was verified that bruise volume and maximum velocity significantly increased with increasing initial height, while its minimum velocity and time of reaching the maximum velocity decreased during the same impact process. With increment of tuber mass, its impact velocities and time of reaching the maximum velocity presented linear change, but the bruise volume nonlinearly changed. The relationships among tuber temperature and impact characteristic parameters were in accordance with linear relationships. The 65 Mn-rubber rod can notably reduce potato impact damage because of its cushioning effect. Potato bruise volume can be predicted based on the maximum and minimum velocity. RESUMO Um estudo foi realizado para investigar a relação entre os fatores (altura inicial, massa de tubérculo, temperatura de tubérculo e impacto material) e as variáveis características do impacto (velocidade e volume da lesão), determinado através do equipamento de teste de impacto de pêndulo. Verificou-se que o volume de contusão e a velocidade máxima aumentaram significativamente com o aumento da altura inicial, enquanto a velocidade mínima e o tempo de atingir a velocidade máxima diminuíram durante o mesmo processo de impacto. Com o incremento da massa do tubérculo, suas velocidades de impacto e tempo de atingir a velocidade máxima apresentaram alteração linear, mas o volume de contusão mudou não linearmente. Enquanto isso, as relações entre temperatura do tubérculo e parâmetros característicos de impacto foram de acordo com relações lineares. A haste de borracha de 65 Mn pode reduzir notavelmente os danos causados pelo impacto da batata devido ao seu efeito amortecedor. O volume de contusões de batata pode ser previsto com base na velocidade máxima e mínima.

A comprehensive study on both the eco-physiological and productive response of potatoes to dynamic deficit irrigation is lacking. Therefore, the aim was to study, over two growing seasons and on two potato cultivars—Arinda and Timate, the effects of five irrigation regimes (I0–dry control, I1—irrigated control, I2—supply 100% of the maximum evapotranspiration—ETm from tuber initiation up to 50% of tuber growth and 0% ETm from 50% to the end of tuber growth, I3—supply 100% of ETm from tuber initiation up to 50% of tuber growth and 50% ETm from 50% to the end of tuber growth, I4—supply 100% of ETm from tuber initiation up to 50% of tuber growth and 75% ETm from 50% to the end of tuber growth) simultaneously on the crop physiology (via chlorophyll fluorescence and leaf gas exchange traits), above-ground biomass yield, tuber yield and its components, irrigation water use efficiency (IWUE), source/sink ratio and tubers’ dry matter content. Regardless of cultivars and seasons, in I3 and I4 for eco-physiological and productive traits, values comparable with I1 were found. Compared to I1, I2 reduced tuber yield by about 18% but increased the IWUE by about 110%, saving a high amount of irrigation water (about 1500 m3 ha−1 per season). Arinda appeared more susceptible than Timate to water deficit in the second part of tuber growth, namely I2, from an eco-physiological point of view, but no differences between cultivars were found from a productive point of view. It was possible to effectively apply dynamic deficit irrigation to save irrigation water without compromising yields strongly.

Main conclusion Nitrogen deficient and drought-tolerant or sensitive potatoes differ in proteomic responses under combined (NWD) and individual stresses. The sensitive genotype ‘Kiebitz’ exhibits a higher abundance of proteases under NWD. Abstract Abiotic stresses such as N deficiency and drought affect the yield of Solanum tuberosum L. tremendously. Therefore, it is of importance to improve potato genotypes in terms of stress tolerance. In this study, we identified differentially abundant proteins (DAPs) in four starch potato genotypes under N deficiency (ND), drought stress (WD), or combined stress (NWD) in two rain-out shelter experiments. The gel-free LC–MS analysis generated a set of 1177 identified and quantified proteins. The incidence of common DAPs in tolerant and sensitive genotypes under NWD indicates general responses to this stress combination. Most of these proteins were part of the amino acid metabolism (13.9%). Three isoforms of S-adenosyl methionine synthase (SAMS) were found to be lower abundant in all genotypes. As SAMS were found upon application of single stresses as well, these proteins appear to be part of the general stress response in potato. Interestingly, the sensitive genotype ‘Kiebitz’ showed a higher abundance of three proteases (subtilase, carboxypeptidase, subtilase family protein) and a lower abundance of a protease inhibitor (stigma expressed protein) under NWD stress compared to control plants. The comparably tolerant genotype ‘Tomba’, however, displayed lower abundances of proteases. This indicates a better coping strategy for the tolerant genotype and a quicker reaction to WD when previously stressed with ND.

A review article on late blightresistance genes.&nbsp

Potato (Solanum tuberosum L.) is often considered a water-sensitive crop and its production can be threatened by drought events, making water stress tolerance a trait of increasing interest. In this study, a panel of 144 tetraploid potato genotypes was evaluated for two consecutive years (2019 and 2020) to observe the variation of several physiological traits such as chlorophyll content and fluorescence, stomatal conductance, NDVI, and leaf area and circumference. In addition, agronomic parameters such as yield, tuber fresh weight, tuber number, starch content, dry matter and reducing sugars were determined. GGP V3 Potato array was used to genotype the population, obtaining a total of 18,259 high-quality SNP markers. Marker-trait association was performed using GWASpoly package in R software and Q + K linear mixed models were considered. This approach allowed us to identify eighteen SNP markers significantly associated with the studied traits in both treatments and years, which were related to genes with known functions. Markers related to chlorophyll content and number of tubers under control and stress conditions, and related to stomatal conductance, NDVI, yield and reducing sugar content under water stress, were identified. Although these markers were distributed throughout the genome, the SNPs associated with the traits under control conditions were found mainly on chromosome 11, while under stress conditions they were detected on chromosome 4. These results contribute to the knowledge of the mechanisms of potato tolerance to water stress and are useful for future marker-assisted selection programs.

During September 2019, public health authorities in El Paso County, Colorado, were notified of four patients who had presented to nearby hospitals with clinical features consistent with botulism, a paralytic illness caused by botulinum neurotoxin. One patient died soon after presentation; the other three patients required intensive care but recovered after receiving botulism antitoxin. Botulinum toxin type A was detected in serum from all patients. On further investigation, all four patients had shared a meal that included commercially prepared roasted potatoes from an individual package without refrigeration instructions that had been left unrefrigerated for 15 d. Storage of the product at ambient temperature likely allowed botulism spores to produce botulinum toxin, resulting in severe illness and death. The manufacturer improved labeling in response to this outbreak. Public health officials should consider unrefrigerated potato products as a potential source of botulism; clinicians should consider botulism as a possible cause of paralytic illness.

Theaflavin (TF), a chemical component important in measuring the quality of fermented tea, has a strong natural antioxidant effect and many pharmacological functions. Enzymatic oxidation has become a widely used method for preparing TFs at the current research stage. Using plant exogenous polyphenol oxidase (PPO) to enzymatically synthesize TFs can significantly increase yield and purity. In this study, tea polyphenols were used as the reaction substrate to discuss the optimal synthesis conditions of potato PPO enzymatic synthesis of theaflavins and the main products of enzymatic synthesis of TFs. The optimal enzymatic synthesis conditions were as follows: pH of the reaction system was 5.5, reaction time was 150 min, substrate concentration was 6.0 mg/mL, reaction temperature was 20 °C, and the maximum amount of TFs produced was 651.75 μg/mL. At the same time, high-performance liquid chromatography was used to determine the content of theaflavins and catechins in the sample to be tested, and the dynamic changes and correlations of the main catechins and theaflavins in the optimal enzymatic system were analyzed. The results showed that epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG) are all the main substrates synthesis of TFs. The main substrate of TFs and its strongest enzymatic catalytic effect on EGCG make theaflavin-3,3'-digallate (TFDG) the most important synthetic monomer. In this study, theaflavins were synthesized by polyphenol oxidase catalysis, which laid a foundation for industrialization of theaflavins.

Aim The newly defined species Pectobacterium parmentieri has emerged as an aggressive pathogen that causes soft rot and blackleg diseases on potato and has been widely disseminated across the globe, jeopardizing the productivity and potato food safety. The implementation of a fast and accurate detection tool is imperative to control, monitor and prevent further spread of these pathogens. The objective of this work was to develop a specific and sensitive multiplex TaqMan qPCR to detect P. parmentieri and distinguish it from all known Pectobacterium species. A universal internal control was included to enhance the reliability of the assay. Methods and Results A comparative genomics approach was used to identify O-acetyltransferase and the XRE family transcriptional regulator as specific targets for primers/probe design for the detection of the Pectobacterium genus and P. parmentieri, respectively. Specificity was assessed with 35 and 25 strains included in the inclusivity and exclusivity panels, respectively, isolated from different geographical locations and sources. The assay specifically detected all 35 strains of Pectobacterium sp. and all 15 P. parmentieri strains. No cross-reactivity was detected during assay validation. Our assay detected up to 10 fg genomic DNA and 1 CFU ml−1 bacterial culture. No change in the detection threshold (1 CFU ml−1) was observed in spiked assays after adding host tissue to the reactions. The assay was validated with naturally and artificially infected host tissues and soil rhizosphere samples. All infected plant samples containing the target pathogens were accurately amplified. Conclusion The presented multiplex TaqMan qPCR diagnostic assay is highly specific, sensitive, reliable for the detection of Pectobacterium species and P. parmentieri with no false positives or false negatives. Significance and Impact of the Study The developed assay can be adopted for multiple purposes such as seed certification programmes, surveillance, biosecurity, microbial forensics, quarantine, border protection, inspections and epidemiology.

Globodera rostochiensis and G. pallida are some of the most successful and highly specialized plant parasitic nematodes and among the most regulated quarantine pests globally. In Switzerland, they have been monitored by annual surveys since their first detection in Swiss soil in 1958. The dataset created was reviewed to produce an overview of the development and actual status of potato cyst nematodes (PCNs) in Switzerland. Positive fields represent 0.2% of all the samples analyzed, and their distribution is limited to central-west and western Switzerland, suggesting that new introduction of PCNs and the spread of the initial introduced PCN populations did not occur. In this way, the integrated management used in Switzerland appears to be effective. However, the increasing availability of potato varieties with resistance to G. rostochiensis and the limited availability of varieties with resistance to G. pallida, together with other biotic and abiotic factors, have promoted changes in the dominance of either species. Consequently, an extended monitoring program is of interest to Swiss farmers, to avoid favoring virulent traits that could be present in Swiss Globodera populations.

A large amount of evidence shows that excessive fat intake can increase the risk of obesity, type 2 diabetes, non-alcoholic fatty liver disease, and cardiovascular disease. The main purpose of this study was to use radio frequency (RF) technology to prepare low-fat French fries.RF treatment for 10 min significantly decreased the force required to cut potatoes and inhibited the enzymatic browning of fresh-cut potatoes. Moreover, RF treatment increased the hardness, gumminess, and chewiness of French fries from 388.55 g, 85.67, and 33.27 to 776.93 g, 159.36, and 70.11, respectively. Furthermore, RF treatment for 10 min reduced the oil content of French fries by 28.0% compared to that of the control group. This result was related to the pre-gelatinized potato starch content after RF treatment. Pre-gelatinized starch forms a 'protective film', that prevents oil from entering the fries during frying.Moderate RF treatment (10 min) reduced the oil content of French fries without making their texture significantly different from that of commercial French fries. These findings may provide a new perspective for the application of RF technology in the development of low-fat fried foods. © 2022 Society of Chemical Industry.