水稻OsYABBY6基因参与叶片发育的初步研究

Preliminary Study on the Rice OsYABBY6 Gene Involving in the Regulation of Leaf Development

水稻YABBY基因家族在植物侧生器官发育过程中起着重要调控作用。在研究中,采用合成型转录因子的方法将转录抑制结构域EAR融合于OsYABBY6的C-端,获得转基因株系CE-OsYABBY6。表型分析发现,转基因株系CE-OsYABBY6-16和CE-OsYABBY6-19成熟期的剑叶均明显表现出朝近轴面卷曲,其卷曲指数相比于野生型均显著提高(P<0.05),说明OsYABBY6参与了水稻叶的发育调控。进一步的细胞组织学分析发现,与野生型相比,CE-OsYABBY6-16叶片横切面中的泡状细胞束的总数、非正常泡状细胞束的数量和比率均显著增加,说明OsYABBY6蛋白与泡状细胞的发育相关。同时,转基因株系CE-OsYABBY6中细胞周期及细胞伸长相关基因的转录水平显著升高,说明OsYABBY6对细胞分裂及生长产生了影响,最终导致了叶片发育的异常。总之,水稻转录因子OsYABBY6参与了叶的近-远轴发育调控,尤其是叶片近轴面的发育调控,而且是泡状细胞发育和叶片伸展所必需的。

The rice YABBY gene family plays important roles in regulating the development of lateral organ. During the experiments, a transcription suppression domain EAR was fused to the C-terminal of OsYABBY6 by the technique of hybrid transcription factors, and the transgenic plants CE-OsYABBY6 were successfully obtained. The phenotypic analysis found that the flag leaves of both CE-OsYABBY6-16 and CE-OsYAB- BY6-19 obviously exhibited adaxial rolling at the mature stage and their leaf rolling indexes were signifi- cantly higher than those of the wild type plants （P〈0.05）, indicating that OsYABBY6 involves in regulating the development of leaves in rice. Then, the histology analysis found that, compared with the wild type, the total number of bulliform cell bundles, the number and ratio of abnormal bulliform cell bundles in the cross-sec- tion of flag leaf blade were markedly increased, suggesting that OsYABBY6 relates with the development of bulliform cells. Meanwhile, the transcriptional levels of cell cycle and cell expansion-related genes were found to be increased obviously, which indicates that OsYABBY6 influences the cell division and expansion, and therefore leads to the abnormal development of entire blade. Together, the rice transcription factor OsYABBY6 involves in regulating the development of leaf adaxial-abaxial axis, especially the adaxial leaf surface, and is necessary for the development of bulliform cells and the expansion of leaves.