SUB1A-mediated submergence tolerance response in rice involves differential regulation of the brassinosteroid pathway
SUB1A-mediated submergence tolerance response in rice involves differential regulation of the brassinosteroid pathway
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DOI：
10.1111/nph.12202
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发表时间：
2013-06-01
期刊：
影响因子：
9.4
通讯作者：
Walia, Harkamal
中科院分区：
文献类型：
--
作者：
Schmitz, Aaron J.;Folsom, Jing J.;Walia, Harkamal
淹水1A（Sub1A）是一种乙烯反应因子（ERF），通过限制水稻在淹水期间的芽伸长而赋予水稻耐淹性。SUB1A被认为是通过调节赤霉酸（GA）信号来限制芽的生长。我们的转录组分析表明，SUB1A差异调节基因与油菜素类固醇（BR）的合成过程中淹没。与基因表达数据相一致，SUB1A基因型与不耐受基因型相比，在淹没后具有更高的油菜素类固醇水平。用外源芸苔素预处理可以激活不耐淹涝基因型的耐淹涝性，从而限制淹涝期间的芽伸长。BR诱导GA分解代谢基因，导致SUB1A植物中较低的GA水平。BR处理还诱导DELLA蛋白SLR1，一种已知的GA反应如芽伸长的阻遏物。我们建议，BR限制GA水平在淹没在SUB1A水稻通过GA分解代谢酶的早期反应的一部分，并可能抑制GA的反应，诱导SLR1后几天的淹没。我们的研究结果表明，BR的生物合成调节SUB1A依赖的方式在淹没过程中，并参与调节GA信号和稳态。
Submergence 1A (SUB1A), is an ethylene response factor (ERF) that confers submergence tolerance in rice (Oryza sativa) via limiting shoot elongation during the inundation period. SUB1A has been proposed to restrict shoot growth by modulating gibberellic acid (GA) signaling. Our transcriptome analysis indicated that SUB1A differentially regulates genes associated with brassinosteroid (BR) synthesis during submergence. Consistent with the gene expression data, the SUB1A genotype had higher brassinosteroid levels after submergence compared to the intolerant genotype. Tolerance to submergence can be activated in the intolerant genotype by pretreatment with exogenous brassinolide, which results in restricted shoot elongation during submergence. BR induced a GA catabolic gene, resulting in lower GA levels in SUB1A plants. BR treatment also induced the DELLA protein SLR1, a known repressor of GA responses such as shoot elongation. We propose that BR limits GA levels during submergence in the SUB1A rice through a GA catabolic enzyme as part of an early response and may repress GA responses by inducing SLR1 after several days of submergence. Our results suggest that BR biosynthesis is regulated in a SUB1A-dependent manner during submergence and is involved in modulating the GA signaling and homeostasis.