The tomato IQD gene SUN24 regulates seed germination through ABA signaling pathway
The tomato IQD gene SUN24 regulates seed germination through ABA signaling pathway
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番茄IQD基因SUN24通过ABA信号通路调控种子萌发
DOI：
10.1007/s00425-018-2950-6
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发表时间：
2018-10-01
期刊：
影响因子：
4.3
通讯作者：
Xiao, Han
中科院分区：
文献类型：
--
作者：
Bi, Lulu;Weng, Lin;Xiao, Han
番茄IQD基因SUN24的基因表达和功能分析表明，该基因通过ABA信号通路调控种子萌发。Ca2+信号在包括aba介导的种子萌发在内的多种生物过程中起着至关重要的作用。植物特异性iq67结构域（IQD）蛋白被假设通过与钙调素（CaMs）的相互作用来调节Ca2+信号和植物发育。尽管已经鉴定出一些IQD基因调控草食抗性和植物生长发育，但该基因家族中大多数成员的分子功能尚不清楚。在本研究中，我们鉴定了番茄IQD基因SUN24在种子萌发中的作用。利用pSUN24::GUS报告系和定量反转录PCR分析发现，SUN24主要在根、花、幼果、种子等幼嫩发育组织中表达，其表达受到ABA处理的抑制。功能分析表明，通过RNA干扰敲低SUN24基因的表达会延迟种子萌发，而过表达SUN24基因则会促进种子萌发。进一步的基因表达分析表明，SUN24在萌发过程中负调控茄茄ABA不敏感基因3 （SlABI3）和SlABI5的表达。此外，靶向微管和核体的SUN24可以与酵母细胞中的4种番茄CaMs （SlCaM1、2、3和6）相互作用。我们的研究结果表明SUN24通过ABA信号通路调控种子萌发，扩大了我们对IQD蛋白家族成员在植物生理过程中的作用的理解。
Gene expression and functional analysis of the tomato IQD gene SUN24 revealed that it regulates seed germination through ABA signaling pathway. Ca2+ signaling plays crucial roles in diverse biological processes including ABA-mediated seed germination. The plant-specific IQ67-Domain (IQD) proteins are hypothesized to regulate Ca2+ signaling and plant development through interactions with calmodulins (CaMs). Despite a few IQD genes have been identified to regulate herbivore resistance and plant growth and development, the molecular functions of most members in this gene family are not known. In this study, we characterized the role of the tomato IQD gene SUN24 in seed germination. Using pSUN24::GUS reporter lines and by quantitative reverse transcription PCR analysis, we show that SUN24 is mainly expressed in the roots, flowers, young fruits, seeds, and other young developing tissues, and its expression is repressed by ABA treatments. Functional analysis shows that knockdown of SUN24 expression by RNA interference delays seed germination, whereas overexpression of this IQD gene promotes germination. Further gene expression analysis reveals that SUN24 negatively regulates expression of two key ABA signaling genes Solanum lycopersicum ABA-insensitive 3 (SlABI3) and SlABI5 in germinating seeds. Moreover, SUN24, targeting to microtubule and nuclear bodies, can interact with four tomato CaMs (SlCaM1, 2, 3, and 6) in yeast cells. Our results demonstrate that SUN24 regulates seed germination through ABA signaling pathway, expanding our understanding of the roles of the IQD protein family members in plant physiological processes.