A 40-bp A/T-rich repressor element involved in organ-dependent transcriptional regulation of ZmGLU1

作者：Zhao, Li; Yuan, Lixing; Gu, Riliang^*

来源：Plant Cell, Tissue and Organ Culture, 2011, 105(3): 291-298.

DOI：10.1007/s11240-010-9867-5

• A/T-rich cis-element
• Promoter
• Transcriptional repression
• ZmGLU1

Maize beta-glucosidase (ZmGLU1) hydrolyzes cytokinin conjugates to release free cytokinins, and regulation of its expression is essential to control cytokinin homeostasis during plant growth and development. Although the promoter of ZmGLU1 gene was found to confer its organ-dependent expression, the underlying mechanism remained to be uncovered. In this study, by promoter deletion assay, a 40-bp A/T-rich sequence in ZmGLU1 promoter region ranging from -798 to -758 (T40) was identified as mediating the repression of promoter activity in seeds and shoot but not in root. Additional fusion of T40 upstream of the constitutive cauliflower mosaic virus 35S promoter (35S) suppressed 35S-driven gene expression in shoot and seeds. Electrophoretic mobility shift assay further revealed a specific interaction between T40 and an unknown binding protein in seeds and shoot but not in root. The negative correlation between ZmGLU1 gene expression/promoter activity and the intensity of T40-protein interaction suggests that T40 acts as a repressor cis-element involved in ZmGLU1 organ-dependent expression. Furthermore, this result provides a new A/T-rich sequence exhibiting transcriptional repression in higher plant.

• 出版日期2011-6
• 单位中国科学院遗传与发育生物学研究所; 中国农业大学