Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China.
National Institute for Genomics and Advanced Biotechnology, Islamabad, Pakistan.
Physiol Plant. 2022 May;174(3):e13696. doi: 10.1111/ppl.13696.
Globally, rice is being consumed as a main staple food and faces different kinds of biotic and abiotic stresses such drought, salinity, and pest attacks. Through the cytokinin signaling, Type-B authentic response regulators (ARR-Bs) respond positively towards the environmental stimuli. ARR-Bs are involved in abiotic stress tolerance and plant development but their molecular mechanisms in fragrant rice are still not fully explored. The current study showed the genome-wide characterization of OsARR-B genes under alkaline salt stress. Results showed that in total, 24 OsARR-B genes were found and divided into four subgroups on the basis of a phylogenetic analysis. These genes were located on all rice chromosomes except 8 and 10. Analysis of gene duplications, gene structure, cis-elements, protein-protein interactions, and miRNA were performed. Gene ontology analysis showed that OsARR-B genes are involved in plant development through the regulation of molecular functions, biological processes, and cellular components. Furthermore, 117 and 192 RNA editing sites were detected in chloroplast and mitochondrial genes, respectively, encoding proteins of OsARR-B. In chloroplast and mitochondrial genes, six and nine types of amino acid changes, respectively, were caused by RNA editing, showing that RNA editing has a role in the alkaline salt stress tolerance in fragrant rice. We also used a comparative transcriptome approach to study the gene expression changes in alkaline tolerant and susceptible genotypes. Under alkaline salt stress, OsARR-B5, OsARR-B7, OsARR-B9, OsARR-B10, OsARR-B16, OsARR-B22, and OsARR-B23 showed higher transcript levels in alkaline salt tolerant genotypes as compared to susceptible ones. Quantitative RT-PCR showed upregulation of gene expression in the alkaline tolerant genotypes under alkaline stress. Our study explored the gene expression profiling and RESs of two rice contrasting genotypes, which will help to understand the molecular mechanisms of alkaline salt tolerance in fragrant rice.
全球范围内，水稻被作为主要主食消费，并面临着各种生物和非生物胁迫，如干旱、盐度和虫害。通过细胞分裂素信号转导，B 型真正的应答调节因子（ARR-Bs）对环境刺激做出积极响应。ARR-Bs 参与非生物胁迫耐受和植物发育，但它们在香稻中的分子机制尚未完全探索。本研究显示了碱性盐胁迫下 OsARR-B 基因的全基因组特征。结果表明，总共发现了 24 个 OsARR-B 基因，并根据系统发育分析将它们分为四个亚组。这些基因位于除 8 号和 10 号染色体之外的所有水稻染色体上。对基因复制、基因结构、顺式作用元件、蛋白质-蛋白质相互作用和 miRNA 进行了分析。基因本体分析表明，OsARR-B 基因通过调节分子功能、生物过程和细胞成分参与植物发育。此外，在叶绿体和线粒体基因中分别检测到 117 和 192 个 RNA 编辑位点，这些基因编码 OsARR-B 的蛋白质。在叶绿体和线粒体基因中，分别有六种和九种类型的氨基酸变化是由 RNA 编辑引起的，表明 RNA 编辑在香稻的耐碱性盐胁迫中起作用。我们还使用比较转录组方法研究了耐碱性和敏感性基因型的基因表达变化。在碱性盐胁迫下，与敏感基因型相比，耐碱性基因型中 OsARR-B5、OsARR-B7、OsARR-B9、OsARR-B10、OsARR-B16、OsARR-B22 和 OsARR-B23 的转录水平更高。定量 RT-PCR 显示在碱性胁迫下，耐碱性基因型中的基因表达上调。我们的研究探索了两种水稻对照基因型的基因表达谱和 RESs，这将有助于理解香稻耐碱性盐胁迫的分子机制。
