甘蓝型油菜BnMPK3的序列分析及其对环境信号的响应

为了分析油菜MAP激酶3对各种环境胁迫信号的表达响应,以甘蓝型油菜中双9号为试材,采用同源克隆法克隆了甘蓝型油菜MAP激酶3基因(Bn MPK3)的c DNA序列。序列分析表明,Bn MPK3编码一条370个氨基酸残基的蛋白序列,这个序列含有1个高度保守的TEY磷酸化位点和一个CD锚定区域,与At MPK3的序列相似性达到94%。烟草瞬时表达分析显示,Bn MPK3是1个细胞核定位蛋白;荧光定量PCR分析显示,Bn MPK3在茎以及花和叶组织器官中特异性表达,并且对Na Cl溶液、4℃低温、PEG溶液和K2Cr2O7溶液以及甲基茉莉酸(Me JA)和乙烯前体(ACC)等的处理显著上调表达。结果表明,Bn MPK3是高盐、低温、干旱、重金属以及JA和ET等各种环境胁迫因子的响应基因,建议Bn MPK3可能在调控油菜对各种环境胁迫防御的过程中位于JA和ET相关的信号网络中,数据将为进一步研究Bn MPK3在油菜抗逆中的功能及其机制提供理论线索。

Sequence Analysis of Brassica napus MAP Kinase 3 and It′s Expression Responses to Environmental Signals

In order to explore the effect of environment signals on the expression of MPK3 in oilseed rape,a full length cDNA of Brassica napus MPK3 (BnMPK3)was cloned from the cv.Zhongshuang No.9 by homology cloning approach.Sequence analysis showed that BnMPK3 contained a highly conserved motif TEY and a CD domain (com-mon docking domain)and was consisted of 370 amino acid residues exhibiting 94% identity with AtMPK3.Transi-ent expression assays in tobacco showed that BnMPK3 is localized in nuclei.Quantitative RT-PCR analysis showed that BnMPK3 was especially expressed in stems,flowers and leaves and revealed that its expression was significantly up-regulated by the treatments with NaCl solution,4 ℃,PEG4000 solution,K2 Cr2 O7 solution or MeJA,ACC solu-tion.The results demonstrated that BnMPK3 was a response gene involved in responses to various environmental stresses including high-salinity,low temperature,drought and heavy metal pollution and to signaling molecules JA and ET,suggesting that BnMPK3 may involve in JA and ET signaling pathways in defense response against various environmental stresses in oilseed rape,which will provide useful information in further in-depth functional analysis of BnMPK3 in defense to environmental stresses.