转运蛋白介导的亚细胞分布调控茉莉酸类植物激素的代谢及信号转导

氧化脂类植物茉莉酸类激素（JAs）包括茉莉酸（JA）及其类似物，是调控植物生长发育、与生物/非生物环境生态互作及次生代谢物（挥发性有机物和青蒿素等）合成的核心激素。同时，JAs也可作为特异性抗癌药物、名贵天然香料及昆虫外激素。JAs在植物中的功能主要通过JA-Ile为配体激活JA核心信号通路来实现。此外，OPDA及茉莉酮（CJ）等JAs则激活独立的信号通路。JAs的合成、代谢和信号转导分别在叶绿体、过氧化物酶体、细胞质及细胞核中进行。我们发现位于细胞质膜和核膜的第一个茉莉酸转运蛋白AtJAT1介导细胞中JA的外运及JA-Ile向细胞核的内运。初步研究发现JAT蛋白家族其他4个成员定位于过氧化物酶体及细胞膜上也介导JA的转运。本项目拟在阐明这些转运蛋白转运特性的基础上，揭示AtJATs通过调节JAs在不同亚细胞区隔中的分布来调控茉莉酸类物质的合成、代谢、信号转导及生态互作的新机制。

The oxylipin plant hormones, jasmonic acid (JA) and its derivatives (collectively referred as jasmonates, JA) play central roles in regulating plant growth and development as well as ecological interactions between plants and their biotic/abiotic environment. Most of these functions are mediated by JA-Ile (as the ligand) activated core JA signaling, however, OPDA or CJ activated JA-Ile-independent signaling is also involved. The biosynthesis, metabolism and signaling of JAs were partitioned in distinct compartments including the chloroplast, peroxisome, cytoplasm and the nucleus. We have identified the first jasmonate transporter, AtJAT1, which mediates the cellular export of JA and nuclear import of JA-Ile. More importantly, our primary results showed that the other 4 members of JAT family were localized in the peroxisomal membrane and plasma membrane. On the basis to characterize the transport properties of these JATs, the aims of this project are to elucidate the roles of the transporter-modulated subcellular distribution of jasmonates in regulating the biosynthesis, metabolism and signaling, and accordingly roles in plant ecological interactions (e. g. systemic immunity, direct and indirect defence). Besides a valuable fragrance and promising anticancer reagent, JAs exhibit similarity in both synthesis and metabolism with prostaglandin and leukotriene in mammals. Hence, our results will provide further insights into a role of transporter-mediated organelle network in cellular metabolism and signaling of oxylipin hormones in both plants and mammals.