Université de Bordeaux, INRA/ ISVV, Ecophysiologie et Génomique Fonctionnelle de la Vigne, Villenave d'Ornon, France.
J Exp Bot. 2013 Feb;64(4):991-1003. doi: 10.1093/jxb/ers374. Epub 2013 Jan 10.
The development of fleshy fruits involves complex physiological and biochemical changes. After fertilization, fruit growth usually begins with cell division, continues with both cell division and expansion, allowing fruit set to occur, and ends with cell expansion only. In spite of the economical importance of grapevine, the molecular mechanisms controlling berry growth are not fully understood. The present work identified and characterized Vitis vinifera cell elongation bHLH protein (VvCEB1), a basic helix-loop-helix (bHLH) transcription factor controlling cell expansion in grape. VvCEB1 was expressed specifically in berry-expanding tissues with a maximum around veraison. The study of VvCEB1 promoter activity in tomato confirmed its specific fruit expression during the expansion phase. Overexpression of VvCEB1 in grape embryos showed that this protein stimulates cell expansion and affects the expression of genes involved in cell expansion, including genes of auxin metabolism and signalling. Taken together, these data show that VvCEB1 is a fruit-specific bHLH transcription factor involved in grape berry development.
肉质果实的发育涉及复杂的生理和生化变化。授粉后，果实生长通常首先是细胞分裂，然后是细胞分裂和扩张同时进行，以确保果实的形成，最后仅进行细胞扩张。尽管葡萄具有重要的经济意义，但控制浆果生长的分子机制尚未完全阐明。本研究鉴定并表征了葡萄细胞伸长 bHLH 蛋白（VvCEB1），它是一种控制葡萄细胞扩张的基本螺旋-环-螺旋（bHLH）转录因子。VvCEB1 在正在扩张的浆果组织中特异性表达，在转色期达到最大值。在番茄中研究 VvCEB1 启动子活性证实了其在扩张期的特异性果实表达。在葡萄胚胎中过表达 VvCEB1 表明该蛋白刺激细胞扩张，并影响参与细胞扩张的基因的表达，包括生长素代谢和信号转导相关基因。综上所述，这些数据表明 VvCEB1 是一种参与葡萄浆果发育的果实特异性 bHLH 转录因子。
