School of Computational & Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India.
Plant Mol Biol. 2021 Jan;105(1-2):205-214. doi: 10.1007/s11103-020-01078-9. Epub 2020 Oct 6.
OsHOX24 mediates regulation of desiccation stress response via complex regulatory network as indicated by its binding to several target genes including transcription factors in rice. HD-ZIP I subfamily of homeobox transcription factors (TFs) are involved in abiotic stress responses and plant development. Previously, we demonstrated the role of OsHOX24, a member of HD-ZIP I subfamily, in abiotic stress responses. In this study, we identified downstream targets of OsHOX24 under control and desiccation stress conditions via chromatin immunoprecipitation-sequencing (ChIP-seq) approach in wild-type and OsHOX24 over-expression transgenic in rice. OsHOX24-binding sites in each sample and differential binding sites between the samples were detected at various genomic locations, including genic and intergenic regions. Gene ontology enrichment analysis revealed that OsHOX24 direct target genes were involved in several biological processes, including plant development, ABA-mediated signalling pathway, ubiquitin-dependent protein catabolic process, ion transport, abiotic and biotic stress responses besides transcriptional and translational regulation. The enrichment of several cis-regulatory motifs representing binding sites of other TFs, such as ABFs, ERF1, MYB1, LTREs and SORLIP2, suggested the involvement of OsHOX24 in a complex regulatory network. These findings indicate that OsHOX24-mediated desiccation stress regulation involves modulation of a plethora of target genes, which participate in diverse pathways in rice.
OsHOX24 通过与其在水稻中结合的几个靶基因（包括转录因子）的复杂调控网络来介导干旱胁迫反应的调节。同源盒转录因子（TFs）的 HD-ZIP I 亚家族参与非生物胁迫反应和植物发育。以前，我们证明了 OsHOX24（HD-ZIP I 亚家族的一员）在非生物胁迫反应中的作用。在这项研究中，我们通过在野生型和 OsHOX24 过表达转基因水稻中进行染色质免疫沉淀测序（ChIP-seq）方法，在对照和干旱胁迫条件下鉴定了 OsHOX24 的下游靶基因。在每个样本中的 OsHOX24 结合位点和样本之间的差异结合位点在各种基因组位置被检测到，包括基因和基因间区域。基因本体富集分析表明，OsHOX24 直接靶基因参与了几个生物学过程，包括植物发育、ABA 介导的信号通路、泛素依赖性蛋白分解代谢过程、离子转运、非生物和生物胁迫反应以及转录和翻译调控。几个顺式调控基序的富集，代表了其他 TFs 的结合位点，如 ABFs、ERF1、MYB1、LTREs 和 SORLIP2，表明 OsHOX24 参与了一个复杂的调控网络。这些发现表明，OsHOX24 介导的干旱胁迫调节涉及调节大量的靶基因，这些靶基因参与了水稻中的多种途径。
