Biotic and Abiotic stress
Alireza Tarang
Abstract
Rice (Oryza sativa) is very sensitive to drought stress because of its limited adaptation to water-deficit conditions. Drought stress alters morphological, physiological, biochemical, and molecular responses in plant. In this study, the effects of drought stress on morphological traits and expression ...
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Rice (Oryza sativa) is very sensitive to drought stress because of its limited adaptation to water-deficit conditions. Drought stress alters morphological, physiological, biochemical, and molecular responses in plant. In this study, the effects of drought stress on morphological traits and expression of transcription factor genes DREB2A and ZFP252 at vegetative and reproductive stages were investigated in TH1 line (drought sensitive) and Neda (drought tolerant). Drought stress was induced by stopping irrigation at tillering and heading stages. Investigation of morphological traits showed tiller and panicle numbers as production indices were significantly higher in Neda cultivar than TH1 line. Real Time PCR Neda genotype showed a significant increase (3.217 expression ratio) in expression of transcript level of ZFP252 at vegetative stage under drought stress. This indicates the importance of this drought stress responsive gene in acquisition of drought tolerance in this genotype at this stage. Investigation of expression level changes in TH1 line showed significant increase in DREB2A and ZFP252 genes expression under drought stress at the vegetative stage. Gene expression analysis in this study suggesting that tolerant and sensitive plants may be using genetic regulations and different mechanisms to be exposed to stress conditions. Deciphering of these molecular mechanisms will aid to better understand stress tolerance and to select strategies for improving crop productivity facing climate change.
Bioinformatics
Mohammad Mohsenzadeh Golfazani; Alireza Tarang; Ramin Seighalani
Abstract
There is much information about the regulation of gene expression in response to various stresses at the transcriptional level. Nevertheless, there is limited information about this process at the post-transcriptional level. The diversity and complexity of miRNA regulation indicates their importance ...
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There is much information about the regulation of gene expression in response to various stresses at the transcriptional level. Nevertheless, there is limited information about this process at the post-transcriptional level. The diversity and complexity of miRNA regulation indicates their importance in biological processes. Many miRNA regulatory modules can form a complex miRNA-mRNA regulatory network. Therefore, research on miRNA-mRNA regulatory networks can provide valuable information for understanding complex biological processes. These data are very important to further study the stress tolerance mechanisms in plants, especially in rapeseed. In this research, the selection of miRNAs related to drought and salinity stress was made by reviewing the articles on abiotic stresses. Then the target genes were identified using the sequences of mature miRNAs and psRNATarget online software. A gene list of 225 identified target genes was prepared using the UniProt database. Their functional pathway was identified utilizing the DAVID bioinformatics database and KEGG database according to default parameters. Investigations showed that these target genes were involved in several biological pathways including ribosome, spliceosome, proteasome, purine metabolism, selenocompound metabolism, and sulfur metabolism. In addition, the STRING database was used to check co-expression genes. Our result indicated the existence of 37 co-expression genes among the identified target genes.
Molecular Plant Breeding
ََAyda Dorreshte; Alireza Tarang
Abstract
Rice is the most important source of food for more than half of the world's population. Currently, Hashemi rice has the highest area under rice in Guilan province and is better than other varieties in terms of cooking quality and customer satisfaction. In this study, for the study the genetic diversity ...
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Rice is the most important source of food for more than half of the world's population. Currently, Hashemi rice has the highest area under rice in Guilan province and is better than other varieties in terms of cooking quality and customer satisfaction. In this study, for the study the genetic diversity of 20 Hashemi cultivars genotypes and two varieties as control (Hashemi and gowhar- introduced by the Rice Research Institute of Iran), 21 polymorphic markers, morphological traits and grain quality were used. The results showed that all of studied traits had a significant difference at 1% level. The cluster analysis with the help of software R divided the studied genotypes into four groups. Based on the data from 21 markers, in total, 96 alleles were detected with the average of 4.57 alleles per locus. The highest number of alleles was observed in markers RM19 and RM1109 with 6 alleles and minimum number of alleles in marker RM249 with 3 alleles. The average number of effective alleles was 3.97. The RM249 had the lowest value of 2.25 and the RM413 and RM1109 markers had the highest values of 5.65 and 5.21, respectively. The average value of polymorphic information content (PIC) was 0.69 for SSR markers. Based on cluster analysis by using Jaccard coefficient and UPGMA method on the SSR markers, the genotypes were grouped in 4 clusters. In general, the results of cluster analysis of morphological traits and microsatellite markers were in good agreement and they could group individuals based on their geographical origin. Understanding the genetic diversity can further help to breeders in their breeding programs, especially in purification the best genotypes and preserving these genotypes in Iran's rice gene bank.
