The Arabidopsis RNA-Binding Protein AtRGGA Regulates Tolerance to Salt and Drought Stress
The Arabidopsis RNA-Binding Protein AtRGGA Regulates Tolerance to Salt and Drought Stress
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DOI：
10.1104/pp.114.255802
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发表时间：
2015-05-01
期刊：
影响因子：
7.4
通讯作者：
Grillo, Stefania
中科院分区：
文献类型：
--
作者：
Ambrosone, Alfredo;Batelli, Giorgia;Grillo, Stefania
盐和干旱胁迫严重降低了全球范围内的植物生长和作物产量。鉴定胁迫反应和耐受性的基因是植物生物学研究的热点。通过微阵列分析，我们以前确定在马铃薯（马铃薯）StRGGA，编码精氨酸甘氨酸甘氨酸（RGG）盒含有RNA结合蛋白，其表达是特异性诱导马铃薯细胞培养物逐渐暴露于渗透胁迫。在这里，我们表明，拟南芥（拟南芥）的直系同源物，AtRGGA，是一个功能性的RNA结合蛋白所需的适当响应渗透胁迫。AtRGGA基因的表达上调幼苗后，长期暴露于脱落酸（阿坝）和聚乙二醇，而与NaCl处理导致AtRGGA下调。AtRGGA启动子分析表明，在几个组织，包括气孔，控制蒸腾作用的器官的活动。AtRGGA与黄色荧光蛋白的融合表明AtRGGA定位于细胞质和细胞质核周区。此外，rgga基因敲除突变体是超敏感的阿坝在根的生长和生存测试和盐胁迫在萌发和营养阶段。AtRGGA-过表达的植物表现出较高的阿坝和盐胁迫的耐受性，在平板和土壤中，积累较低水平的脯氨酸时，暴露于干旱胁迫。最后，基因表达的全局分析揭示了盐胁迫下转录组的广泛改变，包括几个基因，如抗坏血酸过氧化物酶2，谷胱甘肽S-转移酶TAU 9，和几个小生长素上调RNA样基因，在转基因和敲除植物中表现出相反的表达行为。综上所述，我们的研究结果揭示了AtRGGA在植物响应和适应胁迫的机制中的重要作用。
Salt and drought stress severely reduce plant growth and crop productivity worldwide. The identification of genes underlying stress response and tolerance is the subject of intense research in plant biology. Through microarray analyses, we previously identified in potato (Solanum tuberosum) StRGGA, coding for an Arginine Glycine Glycine (RGG) box-containing RNA-binding protein, whose expression was specifically induced in potato cell cultures gradually exposed to osmotic stress. Here, we show that the Arabidopsis (Arabidopsis thaliana) ortholog, AtRGGA, is a functional RNA-binding protein required for a proper response to osmotic stress. AtRGGA gene expression was up-regulated in seedlings after long-term exposure to abscisic acid (ABA) and polyethylene glycol, while treatments with NaCl resulted in AtRGGA down-regulation. AtRGGA promoter analysis showed activity in several tissues, including stomata, the organs controlling transpiration. Fusion of AtRGGA with yellow fluorescent protein indicated that AtRGGA is localized in the cytoplasm and the cytoplasmic perinuclear region. In addition, the rgga knockout mutant was hypersensitive to ABA in root growth and survival tests and to salt stress during germination and at the vegetative stage. AtRGGA-overexpressing plants showed higher tolerance to ABA and salt stress on plates and in soil, accumulating lower levels of proline when exposed to drought stress. Finally, a global analysis of gene expression revealed extensive alterations in the transcriptome under salt stress, including several genes such as ASCORBATE PEROXIDASE2, GLUTATHIONE S-TRANSFERASE TAU9, and several SMALL AUXIN UPREGULATED RNA-like genes showing opposite expression behavior in transgenic and knockout plants. Taken together, our results reveal an important role of AtRGGA in the mechanisms of plant response and adaptation to stress.