Temperature is an important environmental cue that affects flowering time in plants.The MADS-box transcription factor FLOWERING LOCUS M(FLM)forms a heterodimeric complex with SHORT VEGETATIVE PHASE(SVP)and controls am...Temperature is an important environmental cue that affects flowering time in plants.The MADS-box transcription factor FLOWERING LOCUS M(FLM)forms a heterodimeric complex with SHORT VEGETATIVE PHASE(SVP)and controls ambient temperature-responsive flowering in Arabidopsis.FLM-βand FLM-δ,two major splice variants produced from the FLM locus,exert opposite effects on flowering,but the molecular mechanism by which the interaction between FLM isoforms and SVP affects temperature-responsive flowering remains poorly understood.Here,we show that FLM-βand FLM-δplay important roles in modulating the temperature-dependent behavior,conformation,and stability of SVP.Nuclear localization of SVP decreases as temperature increases.FLM-βis required for SVP nuclear translocation at low temperature,whereas SVP interacts with FLM-δmainly in the cytoplasm at high temperature.SVP preferentially binds to FLM-βat low temperature in tobacco leaf cells.SVP shows high binding affinity to FLM-βat low temperature and to FLM-δat high temperature.SVP undergoes similar structural changes in the interactions with FLM-βand FLM-δ;however,FLM-δlikely causes more pronounced conformational changes in the SVP structure.FLM-δcauses rapid degradation of SVP at high temperature,compared with FLM-β,possibly via ubiquitination.Mutation of lysine 53 or lysine 165 in SVP causes increased abundance of SVP due to reduced ubiquitination of SVP and thus delays flowering at high temperature.Our findings suggest that temperature-dependent differential interactions between SVP and FLM isoforms modulate the temperature-responsive induction of flowering in Arabidopsis.展开更多
基金National Research Foundation of Korea grant(NRF-2022R1A3B1078180to J.H.A.).
文摘Temperature is an important environmental cue that affects flowering time in plants.The MADS-box transcription factor FLOWERING LOCUS M(FLM)forms a heterodimeric complex with SHORT VEGETATIVE PHASE(SVP)and controls ambient temperature-responsive flowering in Arabidopsis.FLM-βand FLM-δ,two major splice variants produced from the FLM locus,exert opposite effects on flowering,but the molecular mechanism by which the interaction between FLM isoforms and SVP affects temperature-responsive flowering remains poorly understood.Here,we show that FLM-βand FLM-δplay important roles in modulating the temperature-dependent behavior,conformation,and stability of SVP.Nuclear localization of SVP decreases as temperature increases.FLM-βis required for SVP nuclear translocation at low temperature,whereas SVP interacts with FLM-δmainly in the cytoplasm at high temperature.SVP preferentially binds to FLM-βat low temperature in tobacco leaf cells.SVP shows high binding affinity to FLM-βat low temperature and to FLM-δat high temperature.SVP undergoes similar structural changes in the interactions with FLM-βand FLM-δ;however,FLM-δlikely causes more pronounced conformational changes in the SVP structure.FLM-δcauses rapid degradation of SVP at high temperature,compared with FLM-β,possibly via ubiquitination.Mutation of lysine 53 or lysine 165 in SVP causes increased abundance of SVP due to reduced ubiquitination of SVP and thus delays flowering at high temperature.Our findings suggest that temperature-dependent differential interactions between SVP and FLM isoforms modulate the temperature-responsive induction of flowering in Arabidopsis.
