热胁迫下拟南芥ARP2对钙信号的调控作用

摘要

The dynamic change of calcium signal plays an important role in plant adaptation to abiotic stresses.In order to understand the mechanism of ARP2 mediated Ca2+ signal under heat stress, we use physiological, molecular and genetic tools to analysis the ARP2 genetic material.The results show that plant lacking ARP2 exhibits enhanced heat-induced increases in [Ca2+]cyt, and hypersensitivity to heat stress.The expression of ARP2 is induced under heat stress, and the mRNA expression level of several HSFs such as HSF-A7A,HSF-B2A is reduced in arp2 mutant.When addition of cyclosporin A(CsA), an inhibitor of mitochondrial permeability transition pore, the increase of [Ca2+]cyt is prevented, and the heat-sensitive phenotype of the arp2 mutant is rescued.These results indicate that the ARP2 regulates mitochondrial-dependent Ca2+ signaling in response to heat stress.%钙信号动态变化在植物适应非生物胁迫中起着重要作用.为了理解热胁迫下1个微丝结合相关蛋白(Actin-Related Protein 2,ARP2)参与调控钙信号的机制,采用生理、分子和遗传手段对ARP2相关遗传材料进行了分析.实验结果发现,和野生型相比,热胁迫下arp2突变体细胞质的钙离子浓度升高,arp2突变体幼苗表现出热敏感表型.ARP2基因的表达受热胁迫的诱导,arp2突变体中热诱导响应的转录因子HSF-A7A、HSF-B2A的表达较野生型低.当外源添加线粒体渗透性转换孔道抑制剂cyclosporin A(CsA)抑制arp2突变体中钙升高时,可以恢复其热敏感的表型.以上研究结果表明,ARP2通过调控线粒体来源的钙信号响应热胁迫.