Tamirisa Srinath, Vudem Dashavantha Reddy, Khareedu Venkateswara Rao
Centre for Plant Molecular Biology, Osmania University, Hyderabad, 500 007, India.
Centre for Plant Molecular Biology, Osmania University, Hyderabad, 500 007, India
J Exp Bot. 2014 Sep;65(17):4769-81. doi: 10.1093/jxb/eru224. Epub 2014 May 27.
A potent cold and drought regulatory protein-encoding gene (CcCDR) was isolated from the subtractive cDNA library of pigeonpea plants subjected to drought stress. CcCDR was induced by different abiotic stress conditions in pigeonpea. Overexpression of CcCDR in Arabidopsis thaliana imparted enhanced tolerance against major abiotic stresses, namely drought, salinity, and low temperature, as evidenced by increased biomass, root length, and chlorophyll content. Transgenic plants also showed increased levels of antioxidant enzymes, proline, and reducing sugars under stress conditions. Furthermore, CcCDR-transgenic plants showed enhanced relative water content, osmotic potential, and cell membrane stability, as well as hypersensitivity to abscisic acid (ABA) as compared with control plants. Localization studies confirmed that CcCDR could enter the nucleus, as revealed by intense fluorescence, indicating its possible interaction with various nuclear proteins. Microarray analysis revealed that 1780 genes were up-regulated in CcCDR-transgenics compared with wild-type plants. Real-time PCR analysis on selected stress-responsive genes, involved in ABA-dependent and -independent signalling networks, revealed higher expression levels in transgenic plants, suggesting that CcCDR acts upstream of these genes. The overall results demonstrate the explicit role of CcCDR in conferring multiple abiotic stress tolerance at the whole-plant level. The multifunctional CcCDR seems promising as a prime candidate gene for enhancing abiotic stress tolerance in diverse plants.
从遭受干旱胁迫的木豆植株消减cDNA文库中分离出一个编码强效冷旱调节蛋白的基因（CcCDR）。CcCDR在木豆中受不同非生物胁迫条件诱导。在拟南芥中过表达CcCDR可增强对主要非生物胁迫（即干旱、盐度和低温）的耐受性，这可通过生物量增加、根长增加和叶绿素含量增加得到证明。转基因植株在胁迫条件下还表现出抗氧化酶、脯氨酸和还原糖水平升高。此外，与对照植株相比，CcCDR转基因植株的相对含水量、渗透势和细胞膜稳定性增强，且对脱落酸（ABA）超敏感。定位研究证实，强烈荧光显示CcCDR可进入细胞核，表明其可能与各种核蛋白相互作用。微阵列分析显示，与野生型植株相比，CcCDR转基因植株中有1780个基因上调。对参与ABA依赖和非依赖信号网络的选定胁迫响应基因进行实时PCR分析，结果显示转基因植株中表达水平更高，这表明CcCDR在这些基因上游起作用。总体结果证明了CcCDR在赋予全株多重非生物胁迫耐受性方面的明确作用。多功能的CcCDR作为增强多种植物非生物胁迫耐受性的主要候选基因似乎很有前景。
