High temperature activates the transcription factor PHYTOCHROME-INTERACTING FACTOR4(PIF4)to stimulate auxin signaling,which causes hypocotyl elongation and leaf hyponasty(thermomorphogenesis).HOOKLESS1(HLS1)is a recen...High temperature activates the transcription factor PHYTOCHROME-INTERACTING FACTOR4(PIF4)to stimulate auxin signaling,which causes hypocotyl elongation and leaf hyponasty(thermomorphogenesis).HOOKLESS1(HLS1)is a recently reported positive regulator of thermomorphogenesis,but the molecular mechanisms by which HLS1 regulates thermomorphogenesis remain unknown.In this study,we initially compared PIF4-and/or HLS1-dependent differential gene expression(DEG)upon high-temperature treatment.We found that a large number of genes are coregulated by PIF4 and HLS1,especially genes involved in plant growth or defense responses.Moreover,we found that HLS1 interacts with PIF4 to form a regulatory module and that,among the HLS1-PIF4-coregulated genes,27.7%are direct targets of PIF4.We also identified 870 differentially alternatively spliced genes(DASGs)in wild-type plants under high temperature.Interestingly,more than half of these DASG events(52.4%)are dependent on both HLS1 and PIF4,and the spliceosome-defective mutant plantsexhibit a hyposensitive response to high temperature,indicating that DASGs are required for thermomorphogenesis.Further comparative analyses showed that the HLS1/PIF4-coregulated DEGs and DASGs exhibit almost no overlap,suggesting that high temperature triggers two distinct strategies to control plant responses and thermomorphogenesis.Taken together,these results demonstrate that the HLS1-PIF4 module precisely controls both transcriptional and posttranscriptional regulation during plant thermomorphogenesis.展开更多
基金This work was supported by the National Natural Science Foundation of China(31970256)the Fok Ying Tong Education Foundation(161023)+1 种基金the Fundamental Research Funds for the Central Universities(lzujbky-2019-kb05)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘High temperature activates the transcription factor PHYTOCHROME-INTERACTING FACTOR4(PIF4)to stimulate auxin signaling,which causes hypocotyl elongation and leaf hyponasty(thermomorphogenesis).HOOKLESS1(HLS1)is a recently reported positive regulator of thermomorphogenesis,but the molecular mechanisms by which HLS1 regulates thermomorphogenesis remain unknown.In this study,we initially compared PIF4-and/or HLS1-dependent differential gene expression(DEG)upon high-temperature treatment.We found that a large number of genes are coregulated by PIF4 and HLS1,especially genes involved in plant growth or defense responses.Moreover,we found that HLS1 interacts with PIF4 to form a regulatory module and that,among the HLS1-PIF4-coregulated genes,27.7%are direct targets of PIF4.We also identified 870 differentially alternatively spliced genes(DASGs)in wild-type plants under high temperature.Interestingly,more than half of these DASG events(52.4%)are dependent on both HLS1 and PIF4,and the spliceosome-defective mutant plantsexhibit a hyposensitive response to high temperature,indicating that DASGs are required for thermomorphogenesis.Further comparative analyses showed that the HLS1/PIF4-coregulated DEGs and DASGs exhibit almost no overlap,suggesting that high temperature triggers two distinct strategies to control plant responses and thermomorphogenesis.Taken together,these results demonstrate that the HLS1-PIF4 module precisely controls both transcriptional and posttranscriptional regulation during plant thermomorphogenesis.
