Fruit morphology is an important agronomical trait of many crops. Here, we identify Sly-miR159 as an important regulator of fruit morphology in tomato, a model species of fleshy-fruit development. We show that Sly-miR159 functions through its target SlGAMYB2 to control fruit growth. Suppression of Sly-miR159 and overexpression of SlGAMYB2 result in larger fruits with a reduced length/width ratio, while loss of function of SlGAMYB2 leads to the formation of smaller and more elongated fruits. Gibberellin (GA) is a major phytohormone that regulates fruit development in tomato. We show the Sly-miR159-SlGAMYB2 pathway controls fruit morphology by modulating GA biosynthesis. In particular, we demonstrate that Sly-miR159 promotes GA biosynthesis largely through the direct repression of the GA biosynthetic gene SlGA3ox2 by SlGAMYB2. Together, our findings reveal the action of Sly-miR159 on GA biosynthesis as a previously unidentified mechanism that controls fruit morphology in tomato. Modulating this pathway may have potential applications in tomato breeding for manipulating fruit growth and facilitating the process of fruit improvement.

中文翻译：

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Sly-miR159 通过调节番茄中 GA 的生物合成来调节果实形态

果实形态是许多作物的重要农艺性状。在这里，我们将 Sly-miR159 鉴定为番茄果实形态的重要调节因子，番茄是肉质果实发育的模型物种。我们表明 Sly-miR159 通过其靶标SlGAMYB2来控制果实生长。抑制 Sly-miR159 和过表达SlGAMYB2 会导致果实更大，长宽比降低，而SlGAMYB2功能丧失会导致果实更小、更细长。赤霉素 (GA) 是调节番茄果实发育的主要植物激素。我们展示了 Sly-miR159- SlGAMYB2途径通过调节 GA 生物合成来控制果实形态。特别是，我们证明 Sly-miR159 主要通过 SlGAMYB2 直接抑制 GA 生物合成基因 SlGA3ox2 来促进GA生物合成。总之，我们的研究结果揭示了 Sly-miR159 对 GA 生物合成的作用，这是一种以前未知的控制番茄果实形态的机制。调节该途径可能在番茄育种中具有潜在的应用，可用于调控果实生长和促进果实改良过程。