Gu Zhimin, Ma Bojun, Jiang Yan, Chen Zhiwei, Su Xuan, Zhang Hongsheng
State key lab of crop genetics and germplasm enhancement, Nanjing Agricultural University, Nanjing, 210095, PR China.
Gene. 2008 May 31;415(1-2):1-12. doi: 10.1016/j.gene.2008.02.011. Epub 2008 Feb 20.
Calcium plays a crucial role as a second messenger in mediating various defense responses under environmental stresses. Calcineurin B-like (CBL) proteins have been implicated as important Ca2+ sensors in plant-specific calcium signaling. Based on the similarity of sequence, ten CBL genes were identified by searching the rice japonica genome database, which were randomly distribute on chromosomes 1, 2, 3, 5, 10 and 12. By semi-quantitative RT-PCR approach the expression pattern of each gene was detected in various organs at the adult stage and seedlings treated with NaCl, PEG and cold stresses or exogenous ABA. The results showed that the induction of each rice CBL gene was not only responsive to different stress conditions, but also organ specific. In vivo targeting experiment revealed that OsCBL8 localized to the plasma membrane, which was consistent with OsCBL4 and SOS3 previously reported. To elucidate the putative function of OsCBL8 gene, transgenic rice plants overexpressing OsCBL8 gene were generated by the Agrobacterium-mediated approach. The OsCBL8 transgenic rice seedlings showed more tolerance to salt stress than non-transgenic seedlings.
钙作为第二信使在介导环境胁迫下的各种防御反应中起着关键作用。类钙调神经磷酸酶B(CBL)蛋白被认为是植物特异性钙信号传导中的重要钙传感器。通过搜索粳稻基因组数据库,基于序列相似性鉴定出10个CBL基因,它们随机分布在第1、2、3、5、10和12号染色体上。采用半定量RT-PCR方法检测了每个基因在成年期各器官以及经NaCl、PEG、冷胁迫或外源ABA处理的幼苗中的表达模式。结果表明,每个水稻CBL基因的诱导不仅对不同胁迫条件有响应,而且具有器官特异性。体内定位实验表明,OsCBL8定位于质膜,这与先前报道的OsCBL4和SOS3一致。为了阐明OsCBL8基因的推定功能,通过农杆菌介导的方法培育了过表达OsCBL8基因的转基因水稻植株。OsCBL8转基因水稻幼苗比非转基因幼苗对盐胁迫表现出更强的耐受性。