通过表达ACC脱氨酶基因控制番茄果实的成熟

The Manipulation and Modification of Fruit Ripening by Expression of ACC Deaminase Gene in Tomato

乙烯在跃变型果实的成熟过程中起着触发呼吸跃变和促进果实成熟的作用。细菌来源的１氨基环丙烷１羧酸（ＡＣＣ）脱氨酶能降解乙烯的直接前体ＡＣＣ，从而抑制植物体内乙烯的合成。我们用ＰＣＲ方法从假单孢杆菌中克隆到ＡＣＣ脱氨酶基因并通过农杆菌介导的方法将其转入番茄（Ｌｙｃｏｐｅｒｓｉｃｕｎｅｓｃｕｌｅｎｔｕｍ）中。再生植株经Ｓｏｕｔｈｅｒｎｂｌｏｔ检测证明，ＡＣＣ脱氨酶基因已整合到番茄基因组中并稳定表达。转基因番茄果实成熟期的推迟时间与体内乙烯的抑制程度有相关性。转基因番茄植株乙烯的合成降低８０％左右，果实在离体条件下可保鲜７５ｄ左右。研究ＡＣＣ脱氢酶基因在植物体内的作用可阐明高等植物体内乙烯的作用机理并为培育耐贮藏果蔬品种打下基础。

The gene encoding ACC deaminase was cloned by PCR and introduced into tomato plants by Agrobacterium mediated transformation.The Southern and Western blot analysis demonstrated that the gene has been integrated into tomato genome and expressed.These's a correlation between the degree of ethylene inhibition and delay in the process of fruit ripening in transgenic tomato fruits.Fruits from these plants exhibited significant delays in ripening and keep fresh for at least 2 months in vitro. In the line best expressing ACC deaminase gene,synthesis of ethylene in plants was reduced by 80%.