Dehydration Response During Vernalization In Arabidopsis Thaliana

Vernalization is the induction of a plant’s flowering process by exposure to the prolonged cold.This process is widely found in winter plants and biennial plants,such as Arabidopsis thaliana,wheat and so on.The histone modification changes during the vernalization treatment.However,it is not clear whether any changes in physiology and dehydration stress resistance with vernalization.FLC encodes MADS protein,which is a key inhibitor in flowering pathway.FLC expression level is promoted by FRIGIDA(FRI)and inhibited by vernalization pathway.During vernalization,the transcription level of FLC reduced.H3K36me3 level at FLC site reduced and H3K27me3 level induced.Our study showed the water loss rate in functional FRI plant was slower than that of non-functional FRI,Col-0.In addition,the stomatal density and ABA sensitivity also reduced in functional FRI plant.These observations suggested that FRI is invoved dehydration stress.To confirm these,we treated the FRI plant with vernalization.With the prolonged vernalization,the water loss increased and was more sensitive to drought,indicating that vernalization reduced the drought resistance of Arabidopsis thaliana.The H3K36me3 reduced and H3K27me3 level induced with vernalization.SDG8 encodess a methyltransferase of H3K36 and promotes the transcription of FLC.Loss of SDG8 fucntion resulted in early flowering and exhibited faster water loss in detached leaves.SUF4 is a transcription factor containing two C2H2 zinc finger motifs,which binds to the promoter of FLC site and promotes the FLC transcripts.The water loss induced with SUF4 mutantion.These results suggestedthat FLC might be involved in drought stress.To verify this result,we obtained FLC mutants and found that a fast rate of leaf water loss in flc and flc were sensitive to drought stress indicating that the vernalization process might lead to drought response through FLC.We further explored the resistance of wheat to drought stress during vernalization.With the prolonged vernalization,the water loss decreased,indicating that vernalization increased the drought resistance of semi-winter wheat.There is difference in resopose to vernalization between winter-annual types of Arabidopsis thaliana and semi-winter wheat.