Transformation of Mangrove betaine/proline transporter gene Bet/ProT2 into rice and salt-tolerance study in transgenic plants | 红树甜菜碱/脯氨酸转运蛋白基因Bet/ProT2转化水稻及耐盐性的研究

Chinese. 克隆了红树植物’白骨壤’中甜菜碱/脯氨酸转运蛋白基因(Bet/ProT2),采用根瘤农杆菌介导的方法,将携带有GFP报告基因的35S-Bet/ProT2-GFP融合质粒转化洋葱表皮细胞,亚细胞定位分析表明,Bet/ProT2是定位在细胞质膜上的跨膜蛋白。进一步利用农杆菌介导法将Bet/ProT2转入粳稻‘日本晴’,鉴定结果表明,Bet/ProT基因已经整合到‘日本晴’的基因组中并有效表达。转Bet/ProT基因水稻的耐盐性明显提高,在甜菜碱和脯氨酸同时或分别存在的条件下,转基因水稻可以在含有150 mmol・L-1 NaCl的液体培养基中正常生长,同时叶片中H2O2含量较低;而野生型水稻在相同处理条件下出现明显枯萎,叶片中H2O2大量积累。结论:红树Bet/ProT2基因能通过吸收甜菜碱和/或脯氨酸来降低氧化伤害,显著提高转基因水稻的耐盐能力。

English. Betaine/proline transporter protein gene(Bet/ProT2)was cloned from Mangrove Avicennia marina.In order to reveal its subcellular localization,35S-Bet/ProT2-GFP fusion plasmid with GFP reporter gene was transferred into onion epidermal cells by Agrobacterium tumefaciens.The results showed that Bet/ProT2 was a trans-membrane protein which was located in the plasma membrane.Bet/ProT2 gene was then transferred into Oryza sativa L.japonica‘Nipponbare’by Agrobacterium tumefaciens to study its biological function.PCR results showed that Bet/ProT2 gene was integrated into rice genome and effectively expressed in transgenic plants.The salt tolerance of transgenic rice was improved significantly in the presence of betaine and/or proline in the liquid medium containing 150 mmol・L-1 NaCl,and the content of H2O2 in the leaves remained at low level under salt stress.Under the same treatment,however,wild-type rice had withered,and massive H2O2 was accumulated in the leaves.These results suggested that Mangrove Bet/ProT2 gene could significantly improve the salt tolerance in the transgenic rice by accumulating compatible solutes and reducing oxidative damage.