Project description:The plant hormone jasmonic acid (JA) has been known as a signal molecule that is induced by various stresses and mediates plant defense responses. Rice O. sativa inductively produces variety of defensive compounds upon abiotic and biotic stress conditions, such as wounding and insect attack. The bHLH transcription factor RERJ1 has previously been identified as JA-inducible factor whose expression is also rapidly induced by wounding. We identified RERJ1-dependent and wound-inducible genes by comparison with transcriptomes of wound treated wild-type and a Tos17-rerj1 defective mutant rice.
Project description:Plants experience different stresses, i.e., abiotic, or biotic, and to combat them, plants re-program the expression of growth-, metabolism-, and resistance-related genes. These genes differ in their synonymous codon usage frequency and show codon usage bias. Here, we investigated the correlation among codon usage bias, gene expression, and underlying mechanisms in rice under abiotic and biotic stress conditions. The results indicated that genes with higher expression (up- or downregulated) levels had high GC content (≥60%), a low effective number of codon usage (≤40), and exhibited strong biases towards the codons with C/G at the third nucleotide position, irrespective of stress received. TTC, ATC, and CTC were the most preferred codons, while TAC, CAC, AAC, GAC, and TGC were moderately preferred under any stress (abiotic or biotic) condition. Additionally, downregulated genes are under mutational pressure (R2 ≥ 0.5) while upregulated genes are under natural selection pressure (R2 ≤ 0.5). Based on these results, we also identified the possible target codons that can be used to design an optimized set of genes with specific codons to develop climate-resilient varieties. Conclusively, under stress, rice has a bias towards codon usage which is correlated with GC content, gene expression level, and gene length.
Project description:The plant hormone jasmonic acid (JA) has been known as a signal molecule that is induced by various stresses and mediates plant defense responses. Rice O. sativa inductively produces variety of defensive compounds upon abiotic and biotic stress conditions, such as wounding and insect attack. The bHLH transcription factor RERJ1 has previously been identified as JA-inducible factor whose expression is also rapidly induced by wounding. We identified RERJ1-dependent and wound-inducible genes by comparison with transcriptomes of wound treated wild-type and a Tos17-rerj1 defective mutant rice. Expression profiling between rice leaves of wild-type and tos17-rerj1 mutant treated by wounding for 0, 0.5, 1 and 2 h was compared using two-color method with two biological replicates.
Project description:The plant hormone jasmonic acid (JA) has been known as a signal molecule that is induced by various stresses and mediates plant defense responses. Rice O. sativa inductively produces variety of defensive compounds upon abiotic and biotic stress conditions, such as wounding and insect attack. We identified wound-inducible genes by comparison with transcriptomes between wounded and untreated wild-type rice leaves.
Project description:The plant hormone jasmonic acid (JA) has been known as a signal molecule that is induced by various stresses and mediates plant defense responses. Rice O. sativa inductively produces variety of defensive compounds upon abiotic and biotic stress conditions, such as wounding and insect attack. We identified wound-inducible genes by comparison with transcriptomes between wounded and untreated wild-type rice leaves. Expression profiling in wild-type rice leaves treated by wounding for 0.5, 1, 2 and 4 h was compared with that in untreated control using two-color method with two biological replicates.
Project description:Flowering time is an important factor determining yield and seed quality in maize. A change in flowering time is a strategy used to survive abiotic stresses. Among abiotic stresses, drought can increase anthesis-silking intervals (ASI), resulting in negative effects on maize yield. We have analyzed the correlation between flowering time and drought stress using RNA-seq and bioinformatics tools. Our results identified a total of 619 genes and 126 transcripts whose expression was altered by drought stress in the maize B73 leaves under short-day condition. Among drought responsive genes, we also identified 20 genes involved in flowering times. Gene Ontology (GO) enrichment analysis was used to predict the functions of the drought-responsive genes and transcripts. GO categories related to flowering time included reproduction, flower development, pollen-pistil interaction, and post-embryonic development. Transcript levels of several genes that have previously been shown to affect flowering time, such as PRR37, transcription factor HY5, and CONSTANS, were significantly altered by drought conditions. Furthermore, we also identified several drought-responsive transcripts containing C2H2 zinc finger, CCCH, and NAC domains, which are frequently involved in transcriptional regulation and may thus have potential to alter gene expression programs to change maize flowering time. Overall, our results provide a genome-wide analysis of differentially expressed genes (DEGs), novel transcripts, and isoform variants expressed during the reproductive stage of maize plants subjected to drought stress and short-day condition. Further characterization of the drought-responsive transcripts identified in this study has the potential to advance our understanding of the mechanisms that regulate flowering time under drought stress.
Project description:A submergence tolerant indica rice cultivar FR13A, was also reported to withstand salt stress and proven in our experiments. The mechanism of tolerance is yet to be studied by forward genetics approach. However, it is known that salt stress tolerance is governed by several QTLs and not by a single gene. To understand the mechanism of such a complex mechanism of salt tolerance we selected, two indica rice genotypes namely, I) FR13A, a tolerant indica variety and ii) IR24, a susceptible genotype for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under constitutive and salt stress conditions at seedling stage. Keywords: Mechanism of salt tolerance