毛竹PeSCL6基因的克隆及其表达分析

SCL6基因是植物保持茎端分生组织未分生状态所必需的关键基因之一。采用RT-PCR和RACE方法从毛竹(Phyllostachys edulis Carr.)中获得一个SCL6同源基因,命名为PeSCL6。该基因全长1 894 bp,其中5'端非编码区60 bp,3'端非编码区211 bp,编码区1 623 bp,共编码540个氨基酸。序列分析表明:PeSCL6基因编码的蛋白含有LHRI、VHIID、LHRII、PFYRE和SAW 5个保守区,属于GRAS家族蛋白; 该蛋白与水稻、玉米、高粱等单子叶植物的SCL6有较高的一致性(70%以上)。实时定量PCR结果表明:PeSCL6基因为组成型表达,且在叶片中的表达丰度最高; 而在即将开花之前和处于盛花期的竹株叶片中PeSCL6表达丰度明显降低,分别为幼龄竹株叶片的1%和14%。PeSCL6基因表达的变化,意味着它可能参与毛竹由营养生长向生殖生长的转换调控。

Cloning and expression analysis of PeSCL6 gene in Phyllostachys edulis Carr.

SCL6 is one of the key genes for plant to maintain the shoot apical meristem tissue in indeterminate state. A homologue gene of SCL6 was cloned from moso bamboo(Phyllostachys edulis Carr.)using RT-PCR and RACE methods, and named as PeSCL6. The full length of PeSCL6 was 1 894 bp including 60 bp 5' untranslated region(UTR), 211 bp 3' UTR and an open reading frame of 1 623 bp, which encoded 489 amino acids. Blastp analysis indicated that PeSCL6 had high identities with SCL6 from monocotyledon plants(all up to more than 70%)such as Zea mays, Oryza sativa and Sorghum bicolor. Real time PCR analysis showed that PeSCL6 expressed constitutively with the highest level in leaves of young seedlings. However, the PeSCL6 expressed much lower in the leaves at adult bamboo at just before and full blooming stages, which were only 1% and 14% of that in young seedling leaves, respectively. The changes of expression level in leaves indicated that PeSCL6 gene might be involved in the switch regulation of moso bamboo from vegetative to reproductive growth.