巴西橡胶树HbCYP450基因克隆与表达分析

Cloning and Expression Analysis of HbP450 Gene in Hevea brasiliensis Muell. Arg.

细胞色素P450氧化酶催化植物初生代谢和次生代谢等多种类型的氧化还原反应。本研究在橡胶树叶片中克隆得到一个CYP450基因,编码516个氨基酸,在3~511位氨基酸序列间存在一个P450超级保守结构域,且存在特征性的血红素结合位点保守序列,与蓖麻、胡杨、毛杨果和大豆CYP450的序列一致性分别为74%、68%、68%和65%。Hb CYP450基因在橡胶树的叶片、花和胶乳中均表达,但在树皮中不表达。该基因的表达量受干旱、机械伤害和白粉病的诱导,在植物激素吲哚乙酸(IAA)、茉莉酸(JA)、乙烯利(ET)、脱落酸(ABA)、水杨酸(SA)和过氧化氢(H_2O_2)作用下,Hb CYP450基因表达量呈现先显著上升后显著下降的规律。说明Hb CYP450是植物P450家族成员,其表达量受白粉菌和逆境诱导。

Cytochrome P450 monooxygenases catalyze a wide varieties of monooxygenation reactions in primary and secondary metabolism in plants. In this study, a CYP450 gene was cloned from rubber tree leaves. It encodes 516 amino acids which has one conserved domain at position 3-511 and a special conserved sequence of heme binding sites. Hb CYP450 has identity of 74%, 68%, 68%, and 65% with Ricinus communis L., Populus euphratica, Populus trichocarpa and Glycine max, respectively. Hb CYP450 expressed in leaf, flower and latex, but no expressed in bark,which expression of gene induced by drought, wounding and powdery mildew disease.Under the treatment of IAA,ABA, SA, JA, ET and H_2O_2, the expression patterns of Hb CYP450 were significantly upregulated, then downregulated dramatically. These results suggest that Hb CYP450 is one of the members of P450 family, and the expression are induced by powdery mildew and stress induction.