Trichome formation (表皮毛形成) has been extensively studied as a mechanistic model for epidermal (表皮的) cell differentiation and cell morphogenesis (形态发生) in plants. However, the genetic and molecular mechanisms underlying trichome formation (i.e. initiation and elongation) in rice remain largely unknown. Here, we report an AP2/ERF transcription factor, Hairy Leaf 6 (HL6), which controls trichome formation in rice. Functional characterization of HL6 revealed that HL6 transcriptionally regulates trichome elongation in rice. Furthermore, the regulation of HL6 in trichome elongation is dependent on functional OsWOX3B, which encodes a homeodomain-containing protein that acts as a key regulator in trichome initiation. Using yeast two-hybrid assays and bimolecular fluorescence complementation tests (双分子荧光互补试验), we determined that HL6 interacts with OsWOX3B to regulate trichome formation and form a protein complex, enhancing the binding ability of HL6 with the auxin-related gene OsYUCCA5. Population genetic analysis indicated that HL6 was under negative selection during rice domestication. Our findings provide new insights in the molecular network of HL6 and OsWOX3B involved in the auxin-mediated pathway that regulates trichome formation in rice.

研究方向：水稻新种质创建、基因多样性分析与优异基因发掘、分子育种、种子质量控制等。

Published online: September 29, 2017.