Genome-Wide Association Study (GWAS) and genome prediction of seedling salt tolerance in bread wheat (Triticum aestivum L.).

BACKGROUND: Salinity tolerance in wheat is imperative for improving crop genetic capacity in response to the expanding phenomenon of soil salinization. However, little is known about the genetic foundation underlying salinity tolerance at the seedling growth stage of wheat. Herein, a GWAS analysis was carried out by the random-SNP-effect mixed linear model (mrMLM) multi-locus model to uncover candidate genes responsible for salt tolerance at the seedling stage in 298 Iranian bread wheat accessions, including 208 landraces and 90 cultivars. RESULTS: A total of 29 functional marker-trait associations (MTAs) were detected under salinity, 100 mM NaCl (sodium chloride). Of these, seven single nucleotide polymorphisms (SNPs) including rs54146, rs257, rs37983, rs18682, rs55629, rs15183, and rs63185 with R2 ≥ 10% were found to be linked with relative water content, root fresh weight, root dry weight, root volume, shoot high, proline, and shoot potassium (K+), respectively. Further, a total of 27 candidate genes were functionally annotated to be involved in response to the saline environment. Most of these genes have key roles in photosynthesis, response to abscisic acid, cell redox homeostasis, sucrose and carbohydrate metabolism, ubiquitination, transmembrane transport, chromatin silencing, and some genes harbored unknown functions that all together may respond to salinity as a complex network. For genomic prediction (GP), the genomic best linear unbiased prediction (GBLUP) model reflected genetic effects better than both bayesian ridge regression (BRR) and ridge regression-best linear unbiased prediction (RRBLUP), suggesting GBLUP as a favorable tool for wheat genomic selection. CONCLUSION: The SNPs and candidate genes identified in the current work can be used potentially for developing salt-tolerant varieties at the seedling growth stage by marker-assisted selection.

Transformer's frequency response analysis results interpretation using a novel cross entropy based methodology.

Transformer defects can be identified by the FRA (frequency response analysis) that is a promising diagnostic technique. Despite the standardization in FRA measuring technique, its results interpretation is yet a research area. Because different faults types can be identified in various frequency bounds of the FRA signatures, it is necessary to identify the possible relationships between specific failures and frequency ranges in this contribution. For this purpose, a real transformer is used to conduct the essential tests, which include both healthy and faulted circumstances (axial displacement (AD), radial deformation (RD), and short-circuits (SC)). To identify efficient characteristics from the produced frequency response traces and improve interpretation accuracy of such traces, a new hyperbolic fuzzy cross entropy (FCE) measure is demonstrated and then utilized for the aim of discrimination and classification of transformer winding defects in pre-defined frequency ranges. After normalizing FRA results of the transformer under healthy and various fault circumstances the lower bounds from such responses have been extracted and then utilized to construct the desired form of the fuzzy sets of healthy and faulted circumstances. Then, a new hyperbolic FCE measure-based discrimination and classification of winding faults methodology is offered on the basis of highest and lowest FCE measure values. The highest FCE measure value between the fuzzy sets of healthy and faulted circumstances such as AD, RD and SC is designated to confirm the occurrence of winding faults in a suitable frequency range. The suggested methodology ensures smart interpretation of FRA signature and accurate classification of winding faults as it can effectively discriminate both healthy and faulted circumstances in the desired frequency ranges. The proposed approaches' performance is tested and compared by applying the experimental data after feature extraction.

Gender Differences in COVID-19 Deceased Cases in Jahrom City, South of Iran.

OBJECTIVE: To evaluate the clinical and epidemiological features of deceased patients and comparing the discrepancies between male and female patients based on high prevalence of coronavirus disease 2019 (COVID-19), its irreversible effects and the rising mortality rate in Jahrom city. METHODS: This is a descriptive-analytical retrospective study that was conducted from the beginning of March 2020 to the end of November 2020. The study population were included all patients with COVID-19 who admitted to Peymaniyeh Hospital in Jahrom and died of COVID-19. Clinical and demographic data were collected from medical records and analyzed by SPSS software. RESULTS: In this study, 61 patients (57.54%) were men and 45 patients (42.36%) were women. The mean age was 68.7±18.33 in men and 68.82±14.24 in women. The mean hospitalization length was 9.69±7.75 days in men and 9.69±7.75 days in women patients. There was no statistically significant difference between men and women patients (p>0.05). The results showed that 17 (27.87%) men and 28 (45.9%) of women patients had hypertension and the prevalence of this disease was significantly higher in women than men (p=0.01). In this study, 7 (11.48%) men and 13 (21.31%) women had hyperlipidemia. The frequency of hyperlipidemia in women cases was significantly higher than in men patients (p=0.024). Men cases' diastolic blood pressure (mean=77.53) was significantly higher than women's diastolic blood pressure at the same time with a mean of 71.42 (p<0.05). CONCLUSION: The findings of the study represented the mortality rate in men which is higher than women patients. The prevalence of underlying diseases such as hypertension and hyperlipidemia were higher in women than men. Despite higher mortality among women, symptoms such as fever and dyspnea were less common in women than men.

Tocopherol deficiency in transgenic tobacco (Nicotiana tabacum L.) plants leads to accelerated senescence.

alpha-Tocopherol constitutes the major lipophilic antioxidant in thylakoid membranes, which cooperates with the soluble antioxidant system to alleviate oxidative stress caused by reactive oxygen species (ROS) during oxygenic photosynthesis. Tocopherol accumulates during leaf senescence, indicating the necessity for increased redox buffer capacity in senescent leaves, and tocopherol deficiency has been shown to restrict sugar export from source leaves by inducing callose plugging in the vasculature. We have generated tocopherol-deficient tobacco plants that contain as few as 1% of wild-type (WT) tocopherol in leaves by silencing homogentisate phytyltransferase (HPT). Employing HPT : RNAi plants, we have assessed the importance of tocopherol during leaf senescence and for sugar export. Irrespective of whorl position, the content of free sugars and starch was lower in HPT : RNAi leaves than in WT during the vegetative phase, and no accumulation of callose or a reduction in sugar exudation compared to WT was evident. Based on our observations, we discuss lipid peroxidation as a potential modulator of tocopherol-mediated signalling. Furthermore, senescence was accelerated in lower leaves of HPT transgenics, as indicated by elevated GS1 and reduced rbcS transcript amounts. Oxidative stress was increased in virescent lower source leaves, suggesting that the lack of tocopherol triggers premature senescence.

Are there Specific In Vivo Roles for alpha- and gamma-Tocopherol in Plants?

Tocopherols belong to the Vitamin E family of amphiphilic antioxidants, together with the subfamily of tocotrienols. They are exclusively synthesized by photosynthetic organisms and consist of a polar chromanol head group and a lipophilic prenyl tail.The Vitamin E pool in dicots is commonly dominated by alpha-tocopherol in leaves and by gamma-tocopherol in seeds. This observation rises the question, whether alpha-tocopherol and gamma-tocopherol are functionally equivalent in protection against various kinds of oxidative stress in planta: superoxide and singlet oxygen evolution are high during oxygenic photosynthesis in leaves, while polyunsaturated fatty acid oxidation is the main target for tocopherols in seeds.We found that transgenic tobacco plants with a substitution of gamma- for alpha-tocopherol in leaves are more tolerant than the wild type towards sorbitol and methyl viologen mediated oxidative stress, which increase lipid peroxidation in the chloroplast stroma. This suggests that gamma-tocopherol is more potent than alpha-tocopherol in protecting against lipid peroxidation in both, seeds and leaves, although its natural abundance is in seeds only. If so, why has alpha-tocopherol accumulation in leaves been favoured during the evolution of land plants and does the abundance of gamma-tocopherol in leaves conceal a disadvantage for plant fitness?

Specific roles of alpha- and gamma-tocopherol in abiotic stress responses of transgenic tobacco.

Tocopherols are lipophilic antioxidants that are synthesized exclusively in photosynthetic organisms. In most higher plants, alpha- and gamma-tocopherol are predominant with their ratio being under spatial and temporal control. While alpha-tocopherol accumulates predominantly in photosynthetic tissue, seeds are rich in gamma-tocopherol. To date, little is known about the specific roles of alpha- and gamma-tocopherol in different plant tissues. To study the impact of tocopherol composition and content on stress tolerance, transgenic tobacco (Nicotiana tabacum) plants constitutively silenced for homogentisate phytyltransferase (HPT) and gamma-tocopherol methyltransferase (gamma-TMT) activity were created. Silencing of HPT lead to an up to 98% reduction of total tocopherol accumulation compared to wild type. Knockdown of gamma-TMT resulted in an up to 95% reduction of alpha-tocopherol in leaves of the transgenics, which was almost quantitatively compensated for by an increase in gamma-tocopherol. The response of HPT and gamma-TMT transgenics to salt and sorbitol stress and methyl viologen treatments in comparison to wild type was studied. Each stress condition imposes oxidative stress along with additional challenges like perturbing ion homeostasis, desiccation, or disturbing photochemistry, respectively. Decreased total tocopherol content increased the sensitivity of HPT:RNAi transgenics toward all tested stress conditions, whereas gamma-TMT-silenced plants showed an improved performance when challenged with sorbitol or methyl viologen. However, salt tolerance of gamma-TMT transgenics was strongly decreased. Membrane damage in gamma-TMT transgenic plants was reduced after sorbitol and methyl viologen-mediated stress, as evident by less lipid peroxidation and/or electrolyte leakage. Therefore, our results suggest specific roles for alpha- and gamma-tocopherol in vivo.