《植物生理学报》 2015, 51(11): 2017-2024

杨树PdMYB161基因的功能分析

庄亚妹^1,2, 唐贤丰², 柴国华², 周功克², 王凯荣^1,*

¹青岛农业大学资源与环境学院, 青岛市农村环境工程研究中心, 山东青岛266109; ²中国科学院青岛生物能源与过程研究所, 山东青岛266101

通信作者：王凯荣；E-mail: krwang1@163.com

摘　要：

杨树R2R3-MYB基因家族包括194个成员, 参与众多生长发育过程。我们前期的研究表明杨树PdMYB90/167是一对同源基因, 在拟南芥中能够调控茎秆次生细胞壁的形成、花器官发育和开花时间。本文从功能上鉴定了PdMYB90/167的另一个同源基因PdMYB161, 生化和遗传证据表明该基因在杨树茎秆木质部大量表达, 编码蛋白定位于细胞核, 在拟南芥中过表达导致转基因植株早衰并倒伏, 茎秆细胞壁变薄, 纤维素、半纤维素和木质素含量降低, 对应基因的表达量也发生显著变化。这些结果意味着PdMYB161基因可能参与杨树茎秆次生木质部的形成和植株衰老。结合以前的研究结果, 我们认为PdMYB161和PdMYB90/167基因在进化过程中可能产生功能异化, 这些结果也为植物同源基因功能进化提供了新证据。

关键词：PdMYB161; 细胞壁; 衰老; 功能分化; 杨树; 拟南芥

收稿：2015-09-01   修定：2015-10-23

资助：国家自然科学基金(31300165)和中科院青岛生物能源与过程研究所所长创新基金(C.GH)。

Functional Analysis of Poplar PdMYB161 Gene in Arabidopsis

ZHUANG Ya-Mei^1,2, TANG Xian-Feng², CHAI Guo-Hua², ZHOU Gong-Ke², WANG Kai-Rong^1,*

¹Qingdao Engineering Research Center for Rural Environment, College of Resource and Environment, Qingdao Agricultural University, Qingdao, Shandong 266109, China; ²Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China

Corresponding author: WANG Kai-Rong; E-mail: krwang1@163.com

Abstract:

Poplar R2R3-MYB gene family contains 194 members, which play diverse roles in developmental and adaptive processes. Our previous results demonstrated that a pair of paralogs PdMYB90 and PdMYB167 function in the regulation of secondary wall formation and flowering time in Arabidopsis. In this paper, a MYB transcription factor designated PdMYB16, highly homologous to PdMYB90/167, was isolated from poplar and further functionally studied in Arabidopsis. We showed that PdMYB161 is highly expressed in xylem and the encoded protein is targeted to nucleus. Ectopic expression of PdMYB161 in Arabidopsis produced abnormal phenotypes, including presenility and thinner stem cell wall thickness than that of the wild type. Immunohistochemical and qRT-PCR analyses showed that the amounts of cellulose, xylan and lignin contents were decreased in PdMYB161 overexpression Arabidopsis plants. These results suggest that PdMYB161 may be involved in secondary wall formation and senescence. Combined with previous results, we speculate that PdMYB161 and PdMYB90/167 might have functional divergence during the evolutionary process.

Key words: PdMYB161; cell wall; senescence; functional divergence; poplar; Arabidopsis