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Phytochemistry
Elsevier Science Ltd.
Phytochemistry

Elsevier Science Ltd.

0031-9422

Phytochemistry/Journal PhytochemistrySCICCRIC
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    Enzyme activity and population genetic structure analysis in wheat associated with resistance to Bipolaris sorokiniana-common root rot diseases

    Qalavand F.Esfahani M.N.Azarm D.A.Vatandoost J....
    10页
    查看更多>>摘要：? 2022 Elsevier LtdCommon root rot disease (CRR) caused by Bipolaris sorokiniana (Sacc.) (Pleosporaceae), is an important fungal disease of wheat, Triticum aestivum (Poaceae), causing considerable yield losses globally. Incorporating genetic resistance in cultivated crops is considered the most efficient and sustainable solution to counter root rot diseases. Moreover, resistance to CCR is quantitative in nature, and thus the mechanism is poorly understood. To this aim, we analyzed the activities of defense-related enzymes; peroxidase (POX), superoxide dismutase (SOD), polyphenol oxidase (PPO), catalase (CAT), phenylalanine ammonia-lyase (PAL), β-1,3-glucanase (GLU) and chitinase (CHI), as well as total phenol content (TPC) to CRR on the three known resistant wheat ‘Alvand’ and ‘Bam’, ‘Mehregan’ at different time points (wpi) following CRR pathogen, B. sorokiniana inoculation. Of which, were selected out of 33 wheat cultivars previously screened for resistance to CRR. We also analyzed the genetic variability of the entire germplasm, 33 wheat cultivars using seven simple sequence repeat (SSR) primer pairs. The activity of antioxidant enzymes was increased in the related resistant genotypes. Of which, ‘Bam’ had the highest increase in PPO, and GLU activities, followed by ‘Alvand’ in SOD, PAL, and CHI significantly. Whereas, ‘Mehregan’ showed the highest level of TPC, POX, and CAT activities. In addition, five out of seven used SSR primers produced a total of 20 polymorphic bands, of which the number of alleles in each gene locus varied within 3–7 bands. The polymorphism information content (PIC) value also ranged from 0.44 to 0.81, with the mean of 0.65, Shannon Information Index (I) between 0.29 and 0.63 with an average of 0.47 per locus, and Nei's gene diversity (h) value varied from 0.16 to 0.44 with an average of 0.32. The average number of effective alleles was 1.52, ranging between 1.21 and 1.8. The gene locus Xgwm 140 showed the highest diversity in the population genetic structure, which explains the ability of the primers to resolve the assayed germplasm. Thus, resistance to CRR in wheat was mainly related to the enhancement of antioxidant enzymes, although the specific metabolic pathways require further study. This study presents new insights for understanding resistance mechanisms of the selected wheat cultivars to CRR, thus improving wheat yield in the future.
      原文链接:
    • NSTL
    • Elsevier

    iPReditor-CMG: Improving a predictive RNA editor for crop mitochondrial genomes using genomic sequence features and an optimal support vector machine

    Liu Q.Tan S.Wang Y.Qin S....
    8页
    查看更多>>摘要：? 2022 Elsevier LtdIn crops, RNA editing is one of the most important post-transcriptional processes in which specific cytidines (C) in virtually all mitochondrial protein-coding genes are converted to uridines (U). Despite extensive recent research in RNA editing, exploring all of the C-to-U editing events efficiently on the genomic scale remains challengeable. Developing accurate prediction methods for the detection of RNA editing sites would dramatically reduce experimental determination. Therefore, we propose a novel method, iPReditor-CMG (improved predictive RNA editor for crop mitochondrial genomes), to predict crop mitochondrial editing sites using genome sequence and an optimised support vector machine (SVM). We first selected three mitochondrial genomes with known RNA editing sites from Arabidopsis thaliana, Brassica napus and Oryza sativa, released by NCBI, as the training and test sets. The genes and their transcripts from self-sequenced tobacco mitochondrial ATPase were selected as the validation set. The iPReditor-CMG first coded the genome sequences as numerical vectors and then performed an efficient feature selection on the high-dimensional feature space, where the SVM was employed in feature selection and following modelling. The average independent prediction accuracy of intraspecific editing sites across three species was 0.85, and up to 0.91 in A. thaliana, which outperformed the reference models. For the interspecific independent prediction, the prediction accuracy between dicotyledons was 0.78 and the accuracy between dicotyledons and monocotyledons was 0.56, which implies that there might be similarity in the C-to-U editing mechanism in close relatives. Finally, the best model was identified with an independent test accuracy of 0.91 and an AUC of 0.88, which suggested that five unreported feature sequences, i.e. TGACA, ACAAC, GTAGA, CCGTT and TAACA, are closely associated with the editing phenomenon. Multiple tests supported that the iPReditor-CMG could be effectively applied to predict editing sites in crop mitochondria, which may further contribute to understanding the mechanisms of site editing and post-transcriptional events in crop mitochondria.
      原文链接:
    • NSTL
    • Elsevier