光敏色素B介导光信号影响水稻的脱落酸途径  

Light signals mediated by phytochrome B affect abscisic acid pathway in rice

作　　者：顾建伟[1,2] 张方[3] 赵杰[1] 周晋军[1,4] 钱凤芹[1] 闫丽华[1] 臧新[2] 谢先芝[1,4] 

机构地区：[1]山东省农业科学院高新技术研究中心,济南250100 [2]郑州大学生物工程系,郑州450001 [3]中国科学院遗传与发育生物学研究所,北京100810 [4]农业部黄淮海作物遗传改良与生物技术重点实验室,济南250100

出　　处：《科学通报》2012年第25期2371-2379,共9页Chinese Science Bulletin

基　　金：山东省自然科学杰出青年科学基金(JQ200911);国家自然科学基金(30971744);转基因生物新品种培育科技重大专项(2009ZX08001-029B)资助

摘　　要：研究表明,拟南芥中光敏色素介导的光信号与植物激素脱落酸(abscisic acid,ABA)途径相互作用.但水稻光敏色素与ABA途径之间是否相互影响仍不清楚.利用野生型和phyB突变体水稻作为研究材料,分析phyB介导的光信号对ABA生物代谢和ABA反应的影响.结果表明,ABA合成代谢相关基因OsNCED1,OsNCED2,OsNCED3和OsNCED4在phyB突变体中的表达水平明显高于野生型,而ABA降解代谢基因OsABAOX1则相反,这可能解释了phyB突变体积累较多内源ABA的原因.外源ABA处理明显抑制黑暗和光照下生长的水稻种子的萌发,但光照条件下ABA对phyB突变体种子萌发的抑制效果更明显.据此推测,phyB感受的光信号消弱了ABA对种子萌发的抑制效果.通过分析部分已报道的种子萌发相关基因在正常或ABA处理的野生型和phyB突变体中的表达水平,结果表明,phyB介导的光信号对水稻种子萌发的调控作用可能与这些基因无关.此外,在红光条件下,ABA处理能够抑制水稻幼苗地上部分的生长,野生型和phyB突变体对ABA处理的反应基本相同;但是ABA对phyB突变体主根生长的抑制效果显著高于野生型,这个结果表明phyB介导的光信号不影响ABA对水稻幼苗地上部分生长的抑制效果,但负调控ABA对主根生长的抑制效果.上述研究结果表明,phyB介导的光信号负调控水稻ABA的积累和ABA反应.本研究揭示了水稻光敏色素对ABA途径的影响,为深入研究光信号途径和ABA途径之间协同调控水稻发育的分子机制奠定了基础.Several evidences revealed the interaction between phytochrome-mediated light signals and plant hormones abscisic acid （ABA） pathway in Arabidopsis. However, interaction between ABA signaling and phytochrome-mediated light signaling in mediating rice growth and development remain unclear. In the present study, we analyzed effects of PhyB-mediated light signals on ABA metabolism and ABA responses using rice wild type （WT） and the phyB mutant. It was observed that transcript levels of ABA biosynthetic genes （including OsNCED1, OsNCED2, OsNCED3 and OsNCED4） were higher in the phyB mutant than those in WT, whereas transcript level of ABA deactivating gene OsABA8OX1 was lower in the phyB mutant than that in WT, which probably contributed to the relatively high ABA content in the phyB mutant. ABA treatment inhibited germination of rice seeds grown either in the dark or under light. However, inhibitory effects of ABA treatment on seed germination were more obvious in phyB mutants relative to that in WT when seeds were grown under light conditions, suggesting that PhyB-mediated light signals attenuated the inhibitory effects triggered by ABA. Meantime, we compared the expression patterns of genes related to seed germination in WT and the phyB mutant grown in the medium with or without ABA. It was deduced that these genes is unlikely to contribute for the promotive effects of phyB-mediated light signals on seed germination. In addition, ABA treatment inhibited growth of both above-ground part and seminal root in rice seedlings. PhyB-mediated light signals did not affect the ABA-induced inhibition of above-ground part growth, but negatively regulate the inhibition of root growth. Taken together, our results suggest that PhyB-mediated light signals negatively regulate ABA accumulation and ABA responses in rice. This work reveals the influence of PhyB-mediated light signals on ABA pathway, which lays the foundation for dissecting the molecular mechanism of coordinated regulation of rice development by light and A

关 键 词：水稻 光敏色素 脱落酸 种子萌发 

分 类 号：S511[农业科学—作物学]