Key message

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.

Abstract

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.

中文翻译：

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OsHOX24结合位点的全基因组发现和水稻干旱胁迫反应的调控

关键信息

OsHOX24 通过复杂的调控网络介导干旱胁迫响应的调控，这可以通过其与包括水稻转录因子在内的多个靶基因的结合来表明。

抽象的

HD-ZIP I 同源框转录因子 (TF) 亚家族参与非生物胁迫反应和植物发育。之前，我们展示了OsHOX24的作用，HD-ZIP I 亚科的成员，在非生物应激反应中。在本研究中，我们通过染色质免疫沉淀测序 (ChIP-seq) 方法在野生型和 OsHOX24 过表达转基因水稻中鉴定了控制和干燥胁迫条件下 OsHOX24 的下游靶标。在各个基因组位置（包括基因和基因间区域）检测到每个样品中的 OsHOX24 结合位点和样品之间的差异结合位点。基因本体富集分析表明，OsHOX24 直接靶基因参与了植物发育、ABA 介导的信号通路、泛素依赖的蛋白质分解代谢过程、离子转运、非生物和生物胁迫反应以及转录和翻译调控等多个生物学过程。几种顺式的富集- 代表其他 TFs 结合位点的调控基序，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参与水稻多种途径的靶基因。