Overexpression of a New Putative Membrane Protein Gene AtMRB1 Results in Organ Size Enlargement in Arabidopsis

作     者：Hua Guan Dingming Kang Min Fan Zhangliang Chen Li-Jia Qu 

作者机构：College of Biological Sciences China Agricultural University Beijing 100094 China College of Agronomy and Biotechnology China Agricultural University Beijing 100094 China National Laboratory of Protein Engineering and Plant Genetic Engineering College of Life Sciences Peking University Beijing 100871 China 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2009年第51卷第2期

页      面：130-139页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 09[农学] 071007[理学-遗传学] 0901[农学-作物学] 090102[农学-作物遗传育种] 

基　　金：Supported by the State Basic Research Program of China (2009CB941503) 

主　　题：Arabidopsis AtMRB1 cell number overexpressor lines organ size. 

摘      要：Arabidopsis AtMRB1 is predicted to encode a novel protein of 432 amino acid residues in length, with four putative transmembrane domains. In the present study, characterization of AtMRB1 is conducted. Green fluorescent protein （GFP） fusion protein assay showed that AtMRB1 was located in the plasma membrane. Transgenic lines overexpressing AtMRB1 driven by a CaMV 35S promoter were generated. Statistic analysis showed that, during the seedling stage, the organ sizes of the transgenic lines including hypocotyl length, root length and root weight were significantly larger than those of the wild type plants under both light and dark conditions. In the adult plant stage, the AtMRB1 overexpressor plants were found to have larger organ sizes in terms of leaf length and width, and increased number of cauline leaves and branches when bolting. Further observation indicated that the larger leaf size phenotype was due to a larger number of mesophyll cells, the size of which was not altered. Quantitative real-time polymerase chain reaction analysis showed that the transcription of ANT, ROT3 and GRF5 were upregulated in the *** plants. These data suggest that AtMRB1 is possibly a positive regulator of organ size development in Arabidopsis, mainly through cell number control.