薄荷R3-MYB转录因子MhTRY应答光信号调控腺毛发育的分子机制研究

薄荷腺毛是合成精油的重要场所，其密度直接影响精油产量。目前薄荷腺毛发育调控机制研究很少，揭示薄荷腺毛发育的关键因子及调控机制，具有重要的理论和应用价值。本项目前期发现低光照处理降低薄荷腺毛密度，并利用暗/光恢复处理转录组数据库筛到一个暗诱导/光抑制表达显著的R3-MYB基因MhTRY，已在拟南芥中初步证实其负调控表皮毛发育；另筛到光调控关键因子HY5的薄荷同源基因MhHY5，其表达趋势与MhTRY相反，推测光信号可能通过MhHY5抑制MhTRY表达来调控薄荷腺毛发育。本项目拟围绕MhTRY，通过构建薄荷过表达和沉默遗传转化材料、蛋白互作等技术明确MhTRY负调控腺毛发育，并利用蛋白-DNA互作技术验证MhHY5抑制MhTRY转录，从分子、细胞、遗传等层面，阐明MhTRY应答光信号调控薄荷腺毛发育的分子机制。本研究将为开发和遗传改良多腺毛、高油量薄荷品种提供科学依据和基因资源。

Mint (Mentha haplocalyx Briq.) glandular trichome serves as an important “factory” for the biosynthesis of essential oils, and its density is a key factor that affects the yield of essential oil. Few studies have been made on the molecular mechanism of transcription regulation in mint glandular trichome development so far. To reveal the key factors and regulatory mechanism of glandular trichome development in mint is of great theoretical and practical value. In our previous work, it was found that low intensity light led to decreased glandular trichome density of mint. A R3-MYB gene MhTRY, which was screened through our transcriptome data, was induced by dark while inhibited by light significantly. It has been preliminarily confirmed in Arabidopsis that MhTRY regulated the trichome development negatively. We also screened a mint homologous gene of HY5 as an key transcription factor in light signaling pathway, named MhHY5. As opposed to MhTRY, the expression of MhHY5 was induced by light while inhibited by dark markedly by gene expression analysis. These results make us to infer that light may regulate the glandular trichome development of mint by inhibiting the expression of MhTRY through MhHY5. This project aims to define the negative role of MhTRY in regulating mint glandular trichome development by gene overexpression and silence in mint, and protein-protein interaction, etc.; and demonstrate that the transcription of MhTRY is inhibited by MhHY5 via protein-DNA interaction. The study above will elucidate the molecular mechanism of MhTRY in regulating mint glandular trichome development responding to light at molecular, cellular and genetic levels. This study will provide theoretical basis and gene resources for the development and genetic improvement of mint varieties with enriched glandular trichomes and high essential oil content.