Kaur Charanpreet, Kumar Gautam, Kaur Suminder, Ansari Mohammad Wahid, Pareek Ashwani, Sopory S K, Singla-Pareek Sneh L
Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110 067, India,
Mol Biol Rep. 2015 Jun;42(6):1139-48. doi: 10.1007/s11033-015-3851-4. Epub 2015 Jan 30.
Salt Overly Sensitive (SOS) pathway comprising SOS1, SOS2 and SOS3 genes has been recognized as the key mechanism controlling ion homeostasis under salinity stress. SOS2 component of this pathway encodes a serine/threonine protein kinase that together with SOS3 activates downstream Na(+)/H(+) antiporter SOS1, reestablishing cellular ion homeostasis under salinity stress. In the present study, we have found that the transcript levels of BjSOS2 are induced in response to various abiotic stresses. We have isolated a 713 bp promoter region of SOS2 gene from Brassica juncea to study the regulation of BjSOS2 under various abiotic stress conditions and further, to examine utility of the cloned upstream region in genetic engineering experiments. For this purpose, 713 bp BjSOS2 promoter:β-glucuronidase (GUS) fusion construct, along with its two subsequent 5' deletion derivatives, D1 (443 bp) and D2 (209 bp), were stably transformed into B. juncea. Functional analysis of transgenic lines revealed significant increase in promoter activity under salinity, desiccation as well as abscisic acid (ABA) treatment which was consistent with increased transcript levels of GUS gene. BjSOS2 promoter possesses strong multi-stress inducible nature, suggesting its involvement in various aspects of stress signaling. Considering the fact that the simultaneous presence of multiple abiotic stress conditions under field conditions is a challenging threat to crop productivity, future studies may utilize the BjSOS2 promoter to drive stress-inducible expression of genes involved in imparting tolerance to multiple stresses.
由SOS1、SOS2和SOS3基因组成的盐过度敏感（SOS）途径已被认为是在盐胁迫下控制离子稳态的关键机制。该途径的SOS2组分编码一种丝氨酸/苏氨酸蛋白激酶，它与SOS3一起激活下游的Na(+)/H(+)反向转运蛋白SOS1，在盐胁迫下重新建立细胞离子稳态。在本研究中，我们发现BjSOS2的转录水平在各种非生物胁迫下被诱导。我们从芥菜中分离出SOS2基因的一个713 bp启动子区域，以研究BjSOS2在各种非生物胁迫条件下的调控，进而检测克隆的上游区域在基因工程实验中的效用。为此，将713 bp的BjSOS2启动子：β-葡萄糖醛酸酶（GUS）融合构建体及其两个随后的5'缺失衍生物D1（443 bp）和D2（209 bp）稳定转化到芥菜中。转基因株系的功能分析表明，在盐胁迫、干旱以及脱落酸（ABA）处理下，启动子活性显著增加，这与GUS基因转录水平的增加一致。BjSOS2启动子具有很强的多胁迫诱导特性，表明其参与胁迫信号传导的各个方面。考虑到田间条件下多种非生物胁迫条件同时存在对作物生产力是一个具有挑战性的威胁，未来的研究可能会利用BjSOS2启动子来驱动参与赋予多种胁迫耐受性的基因的胁迫诱导表达。
