Tissue-specific respiratory burst oxidase homolog-dependent H2O2 signaling to the plasma membrane H+-ATPase confers potassium uptake and salinity tolerance in Cucurbitaceae
Tissue-specific respiratory burst oxidase homolog-dependent H2O2 signaling to the plasma membrane H+-ATPase confers potassium uptake and salinity tolerance in Cucurbitaceae
复制标题
组织特异性呼吸爆发氧化酶同系物依赖性 H2O2 向质膜 H-ATP 酶发出信号，赋予葫芦科钾吸收和耐盐性
DOI：
10.1093/jxb/erz328
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发表时间：
2019-10-15
影响因子：
6.9
通讯作者：
Shabala, Sergey
中科院分区：
文献类型：
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作者：
Huang, Yuan;Cao, Haishun;Shabala, Sergey
钾(K+)是耐盐性的关键决定因素，而H_2O_2被认为是一种重要的信号分子，介导了许多生理反应。然而，关于盐胁迫下H_2O_2信号如何调控根中K+吸收的细节仍不清楚。本研究以同属葫芦科的盐敏性黄瓜和耐盐性南瓜为材料，回答了上述问题。我们认为，南瓜较强的耐盐性与其较强的K+吸收能力和较高的根尖H_2O_2积累有关。转录组分析表明，盐胁迫分别诱导了5816个(3005个上调和2811个下调)和4679个(3965个上调和714个下调)基因在黄瓜和南瓜中的差异表达。在盐胁迫下，编码NADPH氧化酶(呼吸爆发氧化酶同系物D；RBOHD)、14-3-3蛋白(GRF12)、质膜H+-ATPase(AHA1)和钾转运蛋白(Hak5)的DEGS在南瓜中的表达高于黄瓜。NADPH氧化酶抑制剂二苯基碘处理导致南瓜RBOHD、GRF12、AHA1和Hak5表达降低，质膜H+-ATPase活性降低，K+吸收减少，导致南瓜的耐盐性丧失。外源H_2O_2对植株进行预处理，结果正好相反。通过CRISPR/Cas9[簇状规则间隔短回文重复序列(CRISPR)/CRISPR相关蛋白9]敲除南瓜的RBOHD基因，编辑编码序列导致根尖H_2O_2和K+含量降低以及GRF12、AHA1和Hak5的表达，最终导致盐敏感的表型。然而，南瓜RBOHD基因在拟南芥中的异源表达却导致了相反的效果。综上所述，本研究表明根尖依赖于RBOHD的H_2O_2信号对南瓜耐盐性是重要的，并提出了一种新的机制，即由RBOHD介导的质膜H~+-ATPase转录和翻译后激活，该酶操作在Hak5 K+吸收转运体的上游。
Potassium (K+) is a critical determinant of salinity tolerance, and H2O2 has been recognized as an important signaling molecule that mediates many physiological responses. However, the details of how H2O2 signaling regulates K+ uptake in the root under salt stress remain elusive. In this study, salt-sensitive cucumber and salt-tolerant pumpkin which belong to the same family, Cucurbitaceae, were used to answer the above question. We show that higher salt tolerance in pumpkin was related to its superior ability for K+ uptake and higher H2O2 accumulation in the root apex. Transcriptome analysis showed that salinity induced 5816 (3005 up- and 2811 down-) and 4679 (3965 up- and 714 down-) differentially expressed genes (DEGs) in cucumber and pumpkin, respectively. DEGs encoding NADPH oxidase (respiratory burst oxidase homolog D; RBOHD), 14-3-3 protein (GRF12), plasma membrane H+-ATPase (AHA1), and potassium transporter (HAK5) showed higher expression in pumpkin than in cucumber under salinity stress. Treatment with the NADPH oxidase inhibitor diphenylene iodonium resulted in lower RBOHD, GRF12, AHA1, and HAK5 expression, reduced plasma membrane H+-ATPase activity, and lower K+ uptake, leading to a loss of the salinity tolerance trait in pumpkin. The opposite results were obtained when the plants were pre-treated with exogenous H2O2. Knocking out of RBOHD in pumpkin by CRISPR/Cas9 [clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9] editing of coding sequences resulted in lower root apex H2O2 and K+ content and GRF12, AHA1, and HAK5 expression, ultimately resulting in a salt-sensitive phenotype. However, ectopic expression of pumpkin RBOHD in Arabidopsis led to the opposite effect. Taken together, this study shows that RBOHD-dependent H2O2 signaling in the root apex is important for pumpkin salt tolerance and suggests a novel mechanism that confers this trait, namely RBOHD-mediated transcriptional and post-translational activation of plasma membrane H+-ATPase operating upstream of HAK5 K+ uptake transporters.