The Mechanism Of Frozen Memory Of H3K4me3 In Arabidopsis Thaliana

With the frequent occurrence of external adversity,plants have a certain "memory" of adverse environmental stimuli,which is called "stress memory" that can cope with the future stress more quickly and strongly.Signal molecular accumulation and epigenetic regulation are two main pathways of stress memory generation.Histone H3K4me3,as a typical histone methylation modification associated with gene activation,plays an important role in the response on low temperature.However,the role of histone H3K4me3 in the formation and maintenance of frozen memory has not been reported.In this study,Arabidopsis thaliana was used as the research material.The relationship between frozen memory and stress resistance,physiological and molecular mechanism of cold memory formation were discussed through physiological,biochemical tests and molecular experiments.The results are as follows:1.The cold memory production of Arabidopsis seedlings under 0 ? for 3 h was verified.With the increase of stress,the tolerance of plants to low temperature increased and lasted for more than 5 days.The results show that the sustainable frozen memory enhances the resistance of plants to stress.2.The physiological basis of the production of frozen memory was discussed.Soluble sugar and chlorophyll increased in the process of low temperature treatment.Cell metabolites may participate in the formation of frozen memory.It shows that the formation of frozen memory is related to the changes of cell intracellular environment.3.After repeated short-time frozen treatments,the enrichment of H3K4me3 was increased,and the expression level of the corresponding genes was affected.4.The tolerance ability of Arabidopsis wild type,histone methyltransferase atx5 single mutation and atx3/4/5 triple mutation were compared.The results showed that the decrease of H3K4me3 enrichment inhibited the formation of frozen memory and reduced the anti-freeze in mutant plants.In summary,the frozen memory produced after repeated short-term cold treatment enhanced the freezing resistance of plants,and histone H3K4me3 participated in the formation of frozen memory.This study not only enriches the research contents of plant stress responses,but also provides a new perspective for understanding how plants deal with external temperature changes.