Alternative splicing provides a mechanism to regulate LlHSFA3 function in response to heat stress in lily

编号 040021601

推送时间 20191209

研究领域 森林培育 

年份 2019 

类型 期刊 

语种 英语

标题 Alternative splicing provides a mechanism to regulate LlHSFA3 function in response to heat stress in lily

来源期刊 Plant Physiology

期 第216期

发表时间 20191014

关键词 alternative splicing;  heat stress;  lily;  LlHSFA3A;  LlHSFA3B-III;  thermotolerance; 

摘要 Heat stress transcription factors (HSFs) are central regulators of plant responses to heat stress. Their heat-induced transcriptional regulation has been extensively studied; however, their post-transcriptional and post-translational regulation is poorly understood. In a previous study, we established that there were at least two HSFA3 homologs, LlHSFA3A and LlHSFA3B, in lily (Lilium spp.) and that these genes played distinct roles in thermotolerance. Here, we demonstrate that LlHSFA3B is alternatively spliced under heat stress to produce the heat-inducible splice variant LlHSFA3B-III. We further show that LlHSFA3B-III protein localizes in the cytoplasm and nucleus, has no transcriptional activity, and specifically disturbs the protein interactions of intact HSFA3 orthologs LlHSFA3A-I and LlHSFA3B-I. Heterologous expression of LlHSFA3B-III in Arabidopsis thaliana and Nicotiana benthamiana increased plant tolerance of salt and prolonged heat at 40{degree sign}C, yet reduced plant tolerance of acute heat shock at 45{degree sign}C. Conversely, heterologous expression of LlHSFA3A-I caused opposing phenotypes, which were substantially ameliorated by co-expression of LlHSFA3B-III. LlHSFA3B-III interacted with LlHSFA3A-I to limit its transactivation function and temper the function of LlHSFA3A-I, thus reducing the adverse effects of excessive LlHSFA3A-I accumulation. Based on these observations, we propose a regulatory mechanism of HSFs involving heat-inducible alternative splicing and protein interaction, which might be used in strategies to promote thermotolerance and attenuate the heat stress response in crop plants.

服务人员 孙小满

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