沙冬青RING型锌指蛋白基因AmRFP1的克隆与功能初步分析

摘要

利用RT-PCR方法,从强抗逆植物蒙古沙冬青克隆到1个受寒旱诱导的锌指蛋白基因AmRFP1.预测其编码蛋白由366个氨基酸残基组成,其中含有1个C3H2C3型锌指结构域,故属于RING-H2(C3 H2C3)型锌指蛋白.该蛋白还含有2个跨膜区,很可能定位于细胞质膜.半定量RT-PCR分析表明,在不同季节野外生长沙冬青植株嫩叶中,AmRFP1在夏季只有低水平表达,进入秋季后表达量明显增加,尤其在秋末冬初其表达量迅速增加并达到全年最高峰,但在进入最寒冷的隆冬后又回落至秋季水平并维持到翌年春季基本未变.将该基因在拟南芥中超表达,则明显降低了转基因拟南芥的抗冻性.%A cold and drought inducible gene named AmRFP1 encoding a zinc finger protein was cloned from Ammopiptanthus mongolicus,a plant with very strong resistance to adverse environments,using RTPCR.The predicted protein is composed of 366 amino acid residues and contains a C3H2C3-type zinc finger domain,and therefore it belongs to a RING-H2 (C3H2C3)-type zinc finger protein.It also contains two putative transmembrane domains and most probably locates in plasma membrane.The expression change of AmRFP1 in young leaves of the A.mongolicus plants growing in the wild was examincd in different seasons using the semi-quantitative RT-PCR method.The expression level of AmRFP1 was very low in summer and increased obviously during autumn and reached the peak in the late autumn and early winter.In the coldest midwinter,however,it fallen back to the autumn level which remained basically unchanged in the following spring.Overexpression of AmRFP1 in Arabidopsis markedly reduced the resistance of the transgenic plants to freezing injury.