渗透胁迫与植物激素等对巴西橡胶树HbMT2a基因表达的影响

Effect of Osmotic Stress and Plant Hormones on the Expression of HbMT2a in Rubber Tree(Hevea brasiliensis Muell. Arg.)

采用荧光定量PCR技术分析HbMT2a基因在不同环境因子诱导下,不同部位和不同无性系间的表达模式。结果表明,不同环境条件下,表达模式有一定差异,但PEG、ABA、6-BA和IAA均上调橡胶树无性系热研7-33-97叶片和树皮中的HbMT2a基因表达;在不同器官中,HbMT2a基因的表达量在根中最高、茎中次之、叶中最低,但是,在PEG诱导条件下,HbMT2a基因上调表达的幅度在叶中最大;降低温度可上调叶片中的HbMT2a基因表达;PEG诱导2 h,HbMT2a基因在抗寒橡胶树品种云研77-4叶片中的上调表达量显著高于不抗寒橡胶树品种热垦501。HbMT2a基因的表达容易受环境因子的影响,而且在抗寒性不同的橡胶树品种间的表达模式存在明显差异,有望作为橡胶树抗性育种的一个分子标记。

Metallothioniens （MTs）are a kind of cysteine-rich proteins with low molecular mass and involved in the responses of plant to environmental stresses. Real-time RT-PCR analysis showed that HbMT2a expression was up-regulated by all the tested factors including PEG, ABA, 6-BA and IAA in the leaves and bark tissues of rubber tree clone RY7-33-97 although the expression patterns were somewhat different. Both the level and the up-regulated range of HbMT2a expression were different among different organs with or without PEG treatment. The differential expression pattern of HbMT2a was revealed between the cold-resistant and-sensitive rubber tree clones. Taken all these data together, the expression .of HbMT2a was impressionable to various environmental factors and different between the cold-resistant and-sensitive rubber tree clones with respect to PEG treatment, suggesting that it maight be used as a molecular marker for the early selection for rubber tree clones with high potential of resistance.