Trichomes are specialized epidermal cells that play multiple roles in plant development. However, knowledge about the molecular mechanism of trichome development in rice is limited. In this study, a hairy leaf locus HL6 ^SWWR of rice variety Suwangwanger (SWWR) was identified by map-based cloning. Transgenic complementation and knock-out mutation demonstrated that HL6^SWWR regulated trichomes on leaves and expression levels of HL6^SWWR affected trichome elongation. Transgenic experiments of PRO^SWWR:HL6^NIP and PRO^NIP:HL6^SWWR indicated that the promoter and coding sequences of HL6^SWWR were indispensable for trichome regulation. Sequencing alignment of the promoter and coding regions of HL6 in 22 varieties showed that some cis-binding elements in the promoter region may be related to trichome development, while no decisive variation was found in the coding sequence. Furthermore, RNA-sequencing analysis revealed that 1 415 differential expression genes (DEGs) were detected in hl6^SWWR mutant vs wild type and that 1 010 DEGs were found in HL6^SWWR complementary transgenic line vs wild type. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that most of the DEGs were involved in metabolite pathway, secondary metabolite biosynthesis, plant pathogen interaction and phytohormone signal transduction in both the two groups. The results indicated that these enhanced pathways are critical during trichome development in rice. Taken together, our results provided new views into the regulatory mechanism of trichome formation in rice.

毛滴虫是专门的表皮细胞，在植物发育中起多种作用。但是，关于水稻毛状体发育的分子机制的知识是有限的。在这项研究中，通过基于图谱的克隆鉴定了水稻品种Suwangwanger（SWWR）的毛状叶基因座HL6 ^SWWR。转基因互补和基因敲除突变证明HL6 ^SWWR树叶和表达水平的调控毛HL6 ^SWWR影响毛状体延伸。PRO ^SWWR：HL6 ^NIP和PRO ^NIP：HL6 ^SWWR的转基因实验表明，启动子和编码序列HL6 ^SWWR对于^线虫调节是必不可少的。在22个变种中HL6的启动子和编码区的序列比对显示，启动子区中的一些顺式结合元件可能与毛状体的发育有关，而在编码序列中没有决定性的变化。此外，RNA测序分析显示，在检测到1倍415的差异表达的基因（DEGS）HL6 ^SWWR突变VS野生型和其中发现1 010度的视角HL6 ^SWWR互补转基因线VS野生型。《京都市基因与基因组百科全书》（KEGG）途径分析表明，两组中大多数DEG都参与了代谢途径，次级代谢产物的生物合成，植物病原体相互作用和植物激素信号转导。结果表明，这些增强的途径在水稻毛状体发育中至关重要。综上所述，我们的结果为水稻中毛状体形成的调控机制提供了新观点。