Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China.
J Integr Plant Biol. 2018 Jun;60(6):498-513. doi: 10.1111/jipb.12636. Epub 2018 Mar 30.
GRAS family transcription factors are involved in multiple biological processes in plants. Here, we report that GRAS2 plays a vital role in regulating fruit weight in tomato (Solanum lycopersicum). We establish that the expression of GRAS2 was elevated in ovaries and maintained at a constant level in fertilized ovules. Reduction of GRAS2 expression in transgenic plants reduced fruit weight through modulating ovary growth and cell size. At the metabolic level, downregulation of GRAS2 decreased activities of the gibberellic acid biosynthesis and signal transduction pathways, leading to insufficient levels of active gibberellic acid during the initial ovary development of tomato. Moreover, genotypic diversity of GRAS2 was consistent with the molecular basis of fruit weight evolution, suggesting that GRAS2 contributes to the molecular basis of the evolution of fruit weight in tomato. Collectively, these findings enhance our understanding of GRAS2 functions, in fruit development of tomato, and demonstrate a strong association between the GRAS gene family and fruit development.
GRAS 家族转录因子参与植物的多种生物学过程。在这里，我们报告 GRAS2 在调控番茄（Solanum lycopersicum）果实重量中起着至关重要的作用。我们确定 GRAS2 的表达在子房中升高，并在受精的胚珠中保持恒定水平。在转基因植物中降低 GRAS2 的表达通过调节子房生长和细胞大小来减少果实重量。在代谢水平上，下调 GRAS2 降低了赤霉素生物合成和信号转导途径的活性，导致番茄子房初始发育过程中活性赤霉素水平不足。此外，GRAS2 的基因型多样性与果实重量进化的分子基础一致，表明 GRAS2 有助于番茄果实重量进化的分子基础。总之，这些发现增强了我们对 GRAS2 在番茄果实发育中的功能的理解，并证明了 GRAS 基因家族与果实发育之间存在很强的关联。
