Laboratory for Agro-ecological Process in the Subtropical Region, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Hunan 410125, China.
Planta. 2011 Jul;234(1):47-59. doi: 10.1007/s00425-011-1386-z. Epub 2011 Feb 27.
Many abiotic stimuli, such as drought and salt stresses, elicit changes in intracellular calcium levels that serve to convey information and activate adaptive responses. Ca²⁺ signals are perceived by different Ca²⁺ sensors, and calmodulin (CaM) is one of the best-characterized Ca²⁺ sensors in eukaryotes. Calmodulin-like (CML) proteins also exist in plants, but their functions at the physiological and molecular levels are largely unknown. In this report, we present data on OsMSR2 (Oryza sativa L. Multi-Stress-Responsive gene 2), a novel calmodulin-like protein gene isolated from rice Pei'ai 64S (Oryza sativa L.). Expression of OsMSR2 was strongly up-regulated by a wide spectrum of stresses, including cold, drought, and heat in different tissues at different developmental stages of rice, as revealed by both microarray and quantitative real-time RT-PCR analyses. Analysis of the recombinant OsMSR2 protein demonstrated its potential ability to bind Ca²⁺ in vitro. Expression of OsMSR2 conferred enhanced tolerance to high salt and drought in Arabidopsis (Arabidopsis thaliana) accompanied by altered expression of stress/ABA-responsive genes. Transgenic plants also exhibited hypersensitivity to ABA during the seed germination and post-germination stages. The results suggest that expression of OsMSR2 modulated salt and drought tolerance in Arabidopsis through ABA-mediated pathways.
许多非生物胁迫，如干旱和盐胁迫，会引发细胞内钙离子水平的变化，从而传递信息并激活适应性反应。Ca²⁺信号被不同的 Ca²⁺传感器感知，钙调蛋白（CaM）是真核生物中研究得最好的 Ca²⁺传感器之一。植物中也存在钙调素样（CML）蛋白，但它们在生理和分子水平上的功能在很大程度上是未知的。在本报告中，我们介绍了来自水稻培矮 64S（Oryza sativa L.）的一种新型钙调素样蛋白基因 OsMSR2（Oryza sativa L. 多胁迫响应基因 2）的数据。通过微阵列和定量实时 RT-PCR 分析，发现 OsMSR2 的表达在不同组织和不同发育阶段的水稻中，受到多种胁迫的强烈上调，包括冷、旱、热。对重组 OsMSR2 蛋白的分析表明其具有体外结合 Ca²⁺的潜在能力。OsMSR2 的表达赋予拟南芥（Arabidopsis thaliana）对高盐和干旱的耐受性增强，同时伴随着应激/ABA 响应基因的表达改变。转基因植物在种子萌发和萌发后阶段也表现出对 ABA 的超敏反应。结果表明，OsMSR2 的表达通过 ABA 介导的途径调节拟南芥的盐和干旱耐受性。
