National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Mol Plant. 2017 Nov 6;10(11):1417-1433. doi: 10.1016/j.molp.2017.09.015. Epub 2017 Sep 28.
Trichome formation has been extensively studied as a mechanistic model for epidermal cell differentiation and cell morphogenesis in plants. However, the genetic and molecular mechanisms underlying trichome formation (i.e., initiation and elongation) in rice remain largely unclear. Here, we report an AP2/ERF transcription factor, Hairy Leaf 6 (HL6), which controls trichome formation in rice. Functional analyses revealed that HL6 transcriptionally regulates trichome elongation in rice, which is dependent on functional OsWOX3B, a homeodomain-containing protein that acts as a key regulator in trichome initiation. Biochemical and molecular genetic analyses demonstrated that HL6 physically interacts with OsWOX3B, and both of them regulate the expression of some auxin-related genes during trichome formation, in which OsWOX3B likely enhances the binding ability of HL6 with one of its direct target gene, OsYUCCA5. Population genetic analysis indicated that HL6 was under negative selection during rice domestication. Taken together, our findings provide new insights into the molecular regulatory network of trichome formation in rice.
毛状体的形成已被广泛研究作为植物表皮细胞分化和细胞形态发生的机制模型。然而，水稻毛状体形成（即起始和伸长）的遗传和分子机制在很大程度上仍不清楚。在这里，我们报道了一个 AP2/ERF 转录因子 Hairy Leaf 6（HL6），它控制着水稻毛状体的形成。功能分析表明，HL6 转录调控水稻毛状体的伸长，这依赖于功能 OsWOX3B，它作为毛状体起始的关键调节剂，含有同源域的蛋白质。生化和分子遗传学分析表明，HL6 与 OsWOX3B 发生物理相互作用，它们都在毛状体形成过程中调节一些生长素相关基因的表达，其中 OsWOX3B 可能增强 HL6 与其一个直接靶基因 OsYUCCA5 的结合能力。群体遗传学分析表明，HL6 在水稻驯化过程中受到负选择。总之，我们的研究结果为水稻毛状体形成的分子调控网络提供了新的见解。
