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期 刊 ：植物遗传资源学报 2015年 16卷 4期

关键词：西橡胶树；自根幼态无性系；染色质甲基化酶；表达；DNA甲基化；

Keywords:Hevea brasiliensis, Chromomethylase methyltransferase, Self-rooting juvenile clone, DNA memethylation, Expression,

摘 要 ：通过PCR和RACE技术克隆了巴西橡胶树中一个染色质甲基化酶(Chromomethylase, CMT)基因（HbCMT）。HbCMT长2697 bp，含有2556 bp的阅读框，编码851个氨基酸。推测HbCMT分子量为95.67 KD，等电点为5.38，氨基酸序列与可可、葡萄、黄瓜、鹰嘴豆、番茄、拟南芥CMT家族成员的同源性分别为77％、74％、72%、67%、64%和52%。定量PCR分析表明HbCMT在巴西橡胶树的根、树皮、叶、胶乳中均有表达，其中在胶乳中表达量最低，此外HbCMT在橡胶树自根幼态无性系的胶乳中表达比老态无性系胶乳中的表达低。

Abstract:The full-length cDNA encoding chromomethylase methyltransferase (CMT), designated HbCMT，was isolated from rubber tree by using PCR and RACE techniques. HbCMT was 2697 bp in length and contained an open reading frame of 2556 bp. Sequence analysis revealed that the ORF of HbCMT encode 851 amino acid residues with a total predicted molecular mass of 95.67 kD. The deduced amino acid sequences of HbCMT showed high identities of 77％、74％、72%、67%、64%和52% to those of the CMT from Theobroma cacao, Cucumis sativus, Cicer arietinum, Solanum lycopersicum and Arabidopsis thaliana. Real time quantitative PCR analysis showed that the transcripts of the HbCMT were differentially expressed in the root, the bark, the leaf and the latex of rubber tree. HbCMT transcript expressed at different levels with the lower in self-rooting juvenile clones than in their donor clones.

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