Natural Variation in OsLG3 Increases Drought Tolerance in Rice by Inducing ROS Scavenging

First author: Haiyan Xiong; Affiliations: China Agricultural University (中国农业大学): Beijing, China

Corresponding author: Zichao Li(李自超)

Improving the performance of rice (Oryza sativa L.) under drought stress has the potential to significantly affect rice productivity. Here, we report that the ERF family transcription factor OsLG3 positively regulates drought tolerance in rice. In our previous work, we found that OsLG3 has a positive effect on rice grain length without affecting grain quality. In this study, we found that OsLG3 was more strongly expressed in upland rice (旱稻) than in lowland rice (水稻) under drought-stress conditions. By performing candidate gene association analysis, we found that natural variation in the promoter of OsLG3 is associated with tolerance to osmotic stress (渗透胁迫) in germinating rice seeds. Overexpression of OsLG3 significantly improved the tolerance of rice plants to simulated (模仿的) drought, whereas suppression of OsLG3 resulted in greater susceptibility. Phylogenetic analysis indicated that the tolerant allele of OsLG3 may improve drought tolerance in cultivated japonica rice. Introgression lines and complementation transgenic lines containing the elite allele of OsLG3IRAT109 showed increased drought tolerance, demonstrating that natural variation in OsLG3 contributes to drought tolerance in rice. Further investigation suggested that OsLG3 plays a positive role in drought-stress tolerance in rice by inducing reactive oxygen species scavenging (清除). Collectively, our findings reveal that natural variation in OsLG3 contributes to rice drought tolerance and that the elite allele of OsLG3 is a promising (有前途的) genetic resource for the development of drought-tolerant rice varieties.

提升水稻在干旱胁迫下的表现有助于增加水稻的产量。本文报道了ERF家族转录因子OsLG3正向调控水稻的干旱抗性。在先前的研究中，作者发现OsLG3在不影响水稻籽粒质量的情况下能够显著增长籽粒的长度。本文的研究显示同样在干旱条件下，旱稻中OsLG3基因的表达要比在水稻中要强烈。通过候选基因关联分析，作者发现OsLG3基因启动子区的变异与萌发中种子的渗透胁迫耐受性显著相关。过表达OsLG3能够显著提升植株在模拟干旱条件下的耐受性，而抑制OsLG3基因的表达则回增强植株对干旱的敏感性。进化分析显示OsLG3在栽培稻中的等位基因可能能够增强植株的干旱抗性。包含OsLG3IRAT109优质等位基因的导入系和互补转基因株系干旱抗性增强，说明了OsLG3的自然变异对于水稻干旱抗性有促进作用。进一步的研究显示OsLG3基因通过诱导水稻中活性氧物质的清除进而在干旱胁迫耐受性中发挥正向作用。综上，本文的研究揭示了OsLG3基因的自然变异有利于水稻的干旱抗性，并且OsLG3优质等位基因是水稻抗干旱品种的育种研究中重要的遗传资源。

通讯：李自超 (http://cab.cau.edu.cn/art/2017/6/12/art_27217_141.html)

个人简介：1984年，北京农业大学，学士；1990年，北京农业大学，硕士；2001年，中国农业大学，博士。

研究方向：利用旱稻DH、RIL和导入系群体及其种质资源通过连锁分析和GWAS相结合发掘根系、生理等抗旱相关性状的QTL或基因，利用基因芯片和RNA-Seq等技术研究了旱稻基因表达规律，提出了旱稻抗旱的分子机制；利用稻种核心种质培育的MCC-NAM群体和定向培育的产量性状、耐冷性状的近等基因系，通过连锁分析和GWAS相结合高效发掘和克隆水稻重要功能基因。

doi: https://doi.org/10.1104/pp.17.01492

Journal: Plant Physiology

First Published: 02 August, 2018

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