反义ACS转基因乙烯缺陷型番茄的生理特性

Characters of Postharvest Physiology of Antisense ACS Transgenic Tomato Fruits

反义 ACC合成酶 (ACS)基因番茄的采后生理性状与普通番茄不同 ,该番茄的果实和叶片乙烯以及果实呼吸强度受到抑制 ,果实乙烯释放量为 0 ,没有出现呼吸高峰 ,呼吸强度在 10～ 14 mg.kg-1.h-1之间波动 ,极显著低于对照 (高峰时为 2 4 .55mg.kg-1.h-1)。反义番茄的叶绿素降解和番茄红素的合成亦受阻 ,果实在采后和贮藏期间逐渐变为黄色或桔黄色而番茄红素的合成很少 ,到采后 30 d仅有 0 .0 4 A.g-1(fw)。乙烯催熟采后 30 d的反义番茄 ,番茄红素增加 6 0倍。反义番茄 PG酶活性在采后缓慢上升 ,到采收后的第 4 5天达到最高为 4 5.16μmol.g-1.h-1,但其活性也仅为普通番茄的一半。乙烯利催熟前后 ,反义番茄的

This paper showed the studies on the post harvest physiology of transgenic tomato. Ethylene either from trnasgenic tomato fruit or tomato leaf disk was significantly lower than control. Chlorophyll degradation and lycopene biosynthesis was inhibited in transgenic tomatoes. After 63 days in normal room condition, transgenic tomato eventually developed an orange color but never turned red. During ripening of the control tomato, the level of sugar and titrated acid and the ratio of sugar to titrated acid of transgenic tomato was similar to the control, but level of ascorbic acid was lower than the control. Meanwhile, the firmness of transgenic tomato declined more slowly. After one month of storage, level of sugar and titrated acid and the ratio of sugar to titrated acid of transgenic tomato declined greatly. In addition, PG activity of transgenic tomato showed to be reduced significantly at early stage of ripening, and the maximum level PG activity of transgenic tomato appeared 45 days after breaker, but it was just half as much as that of control. Furthermore, transgenic tomato fruit treated by ethylene failed to show any increase of PG activity.