Wang Hu, Niu Huanhuan, Li Chuang, Shen Guoyan, Liu Xiaofeng, Weng Yiqun, Wu Tao, Li Zheng
State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Department of Vegetable Sciences, Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, China Agricultural University, Beijing, 100193, China.
Hortic Res. 2020 Nov 1;7(1):182. doi: 10.1038/s41438-020-00404-y.
In plants, WUSCHEL-related homeobox1 (WOX1) homologs promote lamina mediolateral outgrowth. However, the downstream components linking WOX1 and lamina development remain unclear. In this study, we revealed the roles of WOX1 in palmate leaf expansion in cucumber (Cucumis sativus). A cucumber mango fruit (mf) mutant, resulting from truncation of a WOX1-type protein (CsWOX1), displayed abnormal lamina growth and defects in the development of secondary and smaller veins. CsWOX1 was expressed in the middle mesophyll and leaf margins and rescued defects of the Arabidopsis wox1 prs double mutant. Transcriptomic analysis revealed that genes involved in auxin polar transport and auxin response were highly associated with leaf development. Analysis of the cucumber mf rl (round leaf) double mutant revealed that CsWOX1 functioned in vein development via PINOID (CsPID1)-controlled auxin transport. Overexpression of CsWOX1 in cucumber (CsWOX1-OE) affected vein patterning and produced 'butterfly-shaped' leaves. CsWOX1 physically interacted with CsTCP4a, which may account for the abnormal lamina development in the mf mutant line and the smaller leaves in the CsWOX1-OE plants. Our findings demonstrated that CsWOX1 regulates cucumber leaf vein development by modulating auxin polar transport; moreover, CsWOX1 regulates leaf size by controlling CIN-TCP genes.
在植物中，与WUSCHEL相关的同源异型盒1（WOX1）促进叶片的中外侧生长。然而，连接WOX1和叶片发育的下游组分仍不清楚。在本研究中，我们揭示了WOX1在黄瓜（Cucumis sativus）掌状叶扩展中的作用。一个黄瓜芒果果实（mf）突变体，由一个WOX1型蛋白（CsWOX1）截短产生，表现出叶片生长异常以及二级叶脉和小叶脉发育缺陷。CsWOX1在叶肉中部和叶缘表达，并挽救了拟南芥wox1 prs双突变体的缺陷。转录组分析表明，参与生长素极性运输和生长素响应的基因与叶片发育高度相关。对黄瓜mf圆叶（rl）双突变体的分析表明，CsWOX1通过类PID蛋白（CsPID1）控制的生长素运输在叶脉发育中起作用。在黄瓜中过表达CsWOX1（CsWOX1-OE）影响叶脉模式并产生“蝴蝶形”叶片。CsWOX1与CsTCP4a发生物理相互作用，这可能解释了mf突变体品系中叶片发育异常以及CsWOX1-OE植株中叶片较小的原因。我们的研究结果表明，CsWOX1通过调节生长素极性运输来调控黄瓜叶脉发育；此外，CsWOX1通过控制CIN-TCP基因来调控叶片大小。
