中文摘要：

克隆了红树植物‘白骨壤’中甜菜碱／脯氨酸转运蛋白基因（BetlProT2），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转人粳稻‘日本晴’，鉴定结果表明，BetlProT2基因已经整合到‘日本晴’的基因组中并有效表达。转Bet/ProT2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150mmol·L^-1NaCl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。

英文摘要：

Betaine/proline transporter protein gene （ Bet/ProT2 ） was cloned from Mangrove Avicennia marina. In order to reveal its subeellular 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.