青蒿JAZ基因克隆及其功能分析

Cloning and functional analysis of JAZ genes in Artemisia annua

茉莉酸(jasmonic acid,JA)能诱导青蒿素生物合成,为进一步解析青蒿JA信号通路,本研究从青蒿中克隆并鉴定2个JA信号通路中的负调控因子JAZ(jasmonate ZIM-domain)基因,分别命名为AaJAZ5和AaJAZ6。这两者均含有JAZ家族特有的保守区域ZIM和Jas。AaJAZ5在叶中表达量最高,其他部位的表达量较低;AaJAZ6在根中的表达量最高,茎中的表达量最低。茉莉酸甲酯(Me JA)和机械伤害处理都能显著提高AaJAZ5和AaJAZ6的表达。通过双分子荧光互补(bimolecular fluorescence complementation,Bi FC)证明,AaJAZ5和AaJAZ6均能与Aa MYC2相互作用,而只有AaJAZ5与Aa COI1存在相互作用,表明AaJAZ5在JA信号通路中可能具有更加重要的作用。本研究为进一步分析青蒿JAZ家族成员的功能分化和JA信号调控青蒿素生物合成的分子机制奠定了基础。

Jasmonic acid（JA） can promote the biosynthesis of artemisinin. To have an insight into the JA signaling in Artemisia annua, two new genes belonging to JAZ family, namely AaJAZ5 and AaJAZ6, were cloned from Artemisia annua, which might be the negative regulators involved in the JA signaling pathway. Bioinformatic analysis showed that AaJAZ5 and AaJAZ6 contained the conserved domains of ZIM and Jas specific to JAZ family. According to tissue profile analysis, AaJAZ5 had the highest expression level in leaf and AaJAZ6 had the highest expression level in root. The expression levels of both AaJAZ5 and AaJAZ6 were markedly elevated by methyl jasmonate and mechanical wounding. The Bi FC results indicated that AaJAZ5, as well as AaJAZ6, physically interacted with Aa MYC2. Importantly, only AaJAZ5 could interact with Aa COI1. The interaction assays given by Bi FC suggested that AaJAZ5 might play a crucial role in JA signaling. This study facilitated the further analysis of the functional divergence of JAZ-family members and the understanding of molecular mechanism on JA signaling to regulate the artemisinin biosynthesis.