Functional Analysis of AtMYBS Genes in Arabidopsis

• Main Authors: Ling-Jen Ma, 馬翎甄
• Other Authors: 陸重安
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/96129811349183043184

碩士 === 國立中央大學 === 生命科學研究所 === 95 === MYB proteins are transcription factors that contain conserved DNA binding domains, and comprise a large gene family which can be grouped into several subfamilies by phylogenic criteria. In plants, there are three types of MYB proteins, R1R2R3, R2R3, and R1/2. Previously, we identified three novel R1/2 type MYB proteins in rice, OsMYBS1, OsMYBS2, and OsMYBS3. They contain a single repeat of MYB DNA binding domain, and are involved in sugar- and hormone-regulated α-amylase genes expression mechanism. On the other hand, similar proteins in barley, HvMCB1 and HvMYBS3 have been reported that they are important transcription factors during barley seed development. However, the physiological functions of MYBSs in plants are still not well known. As Arabidopsis is a powerful model plant, supported by robust bioinformatics and comprehensive mutant collection, we use Arabidopsis to further investigate biological roles of MYBSs in plants. In this study, four different full-length AtMYBS cDNAs were isolated from Arabidopsis, and these genes were expressed ubiquitously in roots, leaves, flowers and siliques with their own unique expression pattern. To study physiological roles of these genes, a gain-of-function strategy was applied by generating over-expression of AtMYBSs transgenic Arabidopsis plants; meanwhile, loss-of-function method was used by screening T-DNA insertion mutants. MYBSs over-expression transgenic lines and T-DNA mutant lines has been identified in this work. These plant materials will be valuable for function analysis on AtMYBSs in the near future. The other part of this study was found gene expressions of AtMYBSs are sugar respondent. Like MYBSs in rice and barley, the TA-box of sugar response element is specifically recognized by AtMYBSs, implying AtMYBSs may play roles in regulation of plant sugar metabolism.