摘要
赤霉素(GAs)是一类重要的植物激素,调控植物生长发育的诸多方面.最近的研究表明,GA也参与对生物与非生物胁迫的响应,然而GA参与非生物胁迫响应的遗传学证据及其机制有待于进一步研究.本实验室前期研究证明,水稻EUI1(ELONGATED UPPERMOST INTERNODE)通过一个新的生化途径降解体内的活性赤霉素分子,并参与调控水稻对病原菌的基础抗病性.本研究发现,eui1突变体对盐胁迫能力降低,而超表达EUI1基因的水稻和拟南芥耐盐性显著提高.进一步研究发现,积累高含量赤霉素的水稻eui1突变体对脱落酸(ABA)的敏感性下降,而赤霉素缺失的EUI1超表达转基因水稻和拟南芥均改变了对于ABA的敏感性.EUI1基因的转录受逆境诱导,其功能缺失与超表达调控了逆境标志基因的表达.综上推测,GA可能是通过影响ABA的信号途径从而改变了植物对非生物胁迫的响应.
Gibberellins （GAs） are important plant hormones that regulate diverse aspects of plant growth and development. Recent studies suggest that GAs are also actively involved in biotic and abiotic stress responses. However, the genetic evidence and underlying mechanism for the roles of GAs in the response to abiotic stress are still not well dissected. Our previous study has demonstrated that the rice EUI1 P450 epoxidizes the active gibberellins in a novel deactivation reaction and is involved in basal disease resistance in rice. Here, we further found that the euil loss-of-function mutant decreased salt tolerance compared to the wild-type control, while overexpression of EUI1 both in rice and Arabidopsis dramatically increased salt tolerance. Consistent with the finding, the euil mutant with higher level of GA was less sensitive to abscisic acid （ABA）, and the transgenic Arabidopsis and rice plants which constitutively express EUI1 and result in GA deficiency were hypersensitive to ABA. We proposed that GAs play a role in abiotic stress response probably through modulating the ABA signaling pathway.
出处
《中国科学：生命科学》
CSCD
北大核心
2013年第12期1119-1126,共8页
Scientia Sinica(Vitae)
基金
国家自然科学基金(批准号:91117018
31100214)资助项目
