桃ABA 8’–羟化酶基因PpeCYP707As在拟南芥中过表达的功能分析

以8年生‘中油4号’油桃为试材,对休眠期的枝条进行ABA和GA处理发现,ABA延迟芽体萌动,GA促进萌芽和提前开花,在桃芽萌发中ABA和GA起拮抗作用。利用转基因技术在拟南芥中过表达桃ABA分解代谢关键酶ABA 8’–羟化酶基因PpeCYP707A1、PpeCYP707A2和PpeCYP707A3,获得纯合株系,RT-PCR结果表明,目的基因在过表达株系中的表达量分别达到对照的23.86倍、7.37倍、3.23倍;过表达株系生长缓慢,抽薹、开花延迟,其中过表达PPECYP707A1株系生长最慢,开花最晚;过表达株系种子萌发和幼苗生长对ABA不敏感,受伤害程度小;10℃低温处理试验证明,过表达株系相对生长速率高于野生型,推测低温条件下,过表达CYP707As正调控拟南芥的生长发育。

Functional Analysis of Peach PpeCYP707As Gene in Arabidopsis thaliana Overexpressing Plants

We used eight-year-old‘Zhongyoutao 4’nectarine as the material and then treated dormant peach branches with hormone. The results showed that ABA delayed bud germination，GA promoted germination and precocious flowering，ABA and GA had the adverse effect on the germination of peach buds. We obtained at least 3 homozygous lines with overexpression of ABA 8’-hydroxylase gene which were key enzyme in ABA catabolism in peach such as PpeCYP707A1，PpeCYP707A2，PpeCYP707A3 in Arabidopsis thaliana by transgenic technique. The results of RT-PCR showed that the expression of target gene in overexpression lines reached 23.86 times，7.37 times and 3.23 times，respectively. The Arabidopsis of overexpression lines showed slow growth，delayed bolting even flowering，which PPECYP707A1 slowest growth and flowering the latest. Relative conductivity and active oxygen analysis showed that seed germination and seedling growth of transgenic Arabidopsis were not sensitive to ABA and the damage degree was lower compared to wild type. Low temperature（10 ℃）treatment results showed that the relative growth rate of transgenic Arabidopsis with overexpressing PpeCYP707As was higher than that of wild type. It is speculated that the overexpression of CYP707As gene may positively regulate the growth and development of Arabidopsis under low temperature condition.