水稻成花素基因Hd3a在ABA调控种子萌发中的功能研究  

The Role of Hd3a Florigen in ABA-mediated Seed Germination in Rice

作　　者：魏会哲 李成章 王帆 张凌豪[1,2] 苏伟 WEI Huizhe;LI Chengzhang;WANG Fan;ZHANG Linghao;SU Wei(Institute of Plant Biology,School of Life Sciences,Fudan University,Shanghai 200438,China;State Key Laboratory of Engineering,Fudan University,Shanghai 200438,China)

机构地区：[1]复旦大学生命科学学院植物科学研究所,上海200438 [2]复旦大学遗传工程国家重点实验室,上海200438

出　　处：《复旦学报（自然科学版）》2023年第2期189-197,共9页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金面上项目(31970530)。

摘　　要：Hd3a(Heading date 3a)是拟南芥成花素基因FT(Flowering Locus T)的同源基因,作为水稻开花的强诱导因子,对短日照条件下水稻的开花具有重要的促进作用。Hd3a在水稻发育中是否具有其他功能,目前的认识仍非常有限。在我们的研究中,通过对Hd3a基因组序列进行生物信息学分析,发现Hd3a的启动子序列包含响应脱落酸(Abscisic Acid,ABA)信号的ABRE(ABA-Responsive Element)元件。荧光素酶发光反应和RT-qPCR分析都证实了Hd3a的转录表达随外源ABA增加而减少。通过不同浓度的ABA处理水稻野生型和hd3a缺失突变体种子,结果表明hd3a缺失突变体种子萌发明显被抑制,暗示了Hd3a缺失导致种子萌发中对ABA敏感性增强,同时hd3a突变体中ABA信号途径响应基因ABI5(ABA Insensitive 5)、ABL1(ABI5-Like1)的表达量升高,表明Hd3a可负调控ABA信号。综上所述,Hd3a可以响应ABA信号调控水稻种子萌发,这些研究结果对于深入理解水稻Hd3a基因的生物学功能具有重要意义。Hd3a(Heading date 3a)is a homolog of Arabidopsis FT,which is a strong induction factor of rice flowering and plays an important role in promoting rice flowering under short-day conditions.However,it is still limited whether Hd3a exists other functions in rice development.In our study,bioinformatics analysis of the genomic sequence of Hd3a revealed that the promoter sequence of Hd3a contains ABRE cis-element involved to abscisic acid(ABA)signaling pathway.To explore the role of Hd3a in response to ABA treatment,luciferase assay and real-time RT-qPCR analysis were performed.Results showed that the transcriptional expression of Hd3a decreased with the increase of exogenous ABA.Compared to the wild type,seed germination of rice hd3a mutant was significantly inhibited by ABA treatment at different concentrations,suggesting that hd3a mutants are more sensitive to ABA.At the same time,the expression levels of ABA signaling pathway response genes ABI5(ABA Insensitive 5)and ABL1(ABI5-like1)were increased in hd3a mutant,suggesting that Hd3a negatively regulates ABA signaling.In conclusion,Hd3a regulates rice seed germination in response to ABA signaling.These results are important for further understanding the biological function of Hd3a gene in rice.

关 键 词：水稻 脱落酸 成花素 种子萌发 

分 类 号：Q522[生物学—生物化学]