野生大豆类受体蛋白激酶基因GsCBRLK超量表达提高水稻耐盐碱性

Overexpression of a Glycine soja receptor-like protein kinase gene GsCBRLK in rice increases salt-alkaline tolerance

类受体蛋白激酶是一个庞大的基因家族,在植物抗逆反应中具有重要作用。前期从野生大豆中鉴定了耐盐碱功能显著的类受体蛋白激酶GsCBRLK,本研究着重关注GsCBRLK在提高水稻耐盐碱性中的应用。生物信息学分析发现GsCBRLK属于CRCK1亚家族,该亚家族在水稻、大豆和拟南芥中蛋白序列高度保守,尤其是激酶结构域。利用农杆菌侵染水稻愈伤组织,经PCR、RT-PCR和qRT-PCR检测获得4个GsCBRLK转基因株系。通过对比野生型和转基因水稻盐碱处理表型、存活率、相对含水量、相对电导率、Na+/K+含量、活性氧积累以及POD和CAT活性,发现GsCBRLK转基因株系耐盐碱性显著优于野生型。qRT-PCR分析发现盐碱处理后OsCATA、OsCATB、OsNAC5和OsP5CR基因在GsCBRLK转基因株系中表达显著高于野生型。上述结果表明GsCBRLK转基因水稻的耐盐碱性显著提高,对于提高盐碱地水稻产量具有重要意义。

Receptor-like protein kinase(RLK) family is one of the largest gene families with numerous members, and plays important roles in plant stress response. In previous studies, GsCBRLK, a Glycine soja calcium/calmodulin-binding receptor-like kinase, was suggested to significantly improve salt-alkaline tolerance. This study focused on the potential of GsCBRLK in enhancing the salt-alkaline tolerance of rice. Bioinformatic analysis revealed that GsCBRLK belonged to the CRCK1 subfamily, and this subfamily was highly conserved among rice, soybean and Arabidopsis in terms of protein sequences, especially the kinase domain. By using the Agrobacterium infecting rice callus, four GsCBRLK overexpression transgenic lines were generated after PCR, RT-PCR and qRT-PCR identification. By comparing the phenotype, survival rates, relative water content, relative ion leakage, Na+ and K+ content, ROS accumulation, POD and CAT activity of the wild type and transgenic lines under salt-alkaline stress, we found that GsCBRLK transgenic lines showed significantly higher tolerance to salt-alkaline stress than the wild type. Quantitative real-time PCR analysis showed that transcript levels of OsCATA, OsCATB, Os NAC5 and OsP5 CR were significantly higher in the transgenic lines than the wild type after salt-alkaline treatment. The results demonstrate the increased salt-alkaline tolerance of GsCBRLK transgenic lines, which is of great significance for increasing the rice yields in salt-alkaline soils.