The Role Of Chromatin Remodeling Complex ATPases CHR12 And CHR23 In Arabidopsis Thaliana Under Stress

During the growth and development of the model plant Arabidopsis thaliana,chromatin remodeling complexes are involved in the regulation of plant responses to temperature,drought,salinity and pathogens.In this study,we tried to use physiological and biochemical,qPCR,transcriptome and BiFC methods to explore the role of chromatin remodeling complex ATP enzymes CHR12 and CHR23 in stress response.The main results are as follows:1.The phenotypes of single mutants of chr12 or chr23 or plants with decreased expression of CHR12 and CHR23 were close to WT through supplementation experiment and amiRNA experiment.Only complete deletion of CHR12 and CHR23 could cause serious phenotypic defects,and this defect phenotype could be restored,which also proved that CHR12 and CHR23 play an important role in maintaining normal growth and development of plants.2.Through the experiment that WT and chr12 chr23 double mutants were treated with mannitol or PEG6000 to simulate the effect of drought stress,it was found that the root length of chr12 chr23 double mutants was significantly smaller than that of WT under different concentrations of osmotic stress,indicating that chr12 chr23 double mutants had stronger tolerance to osmotic stress.3.Physiological experiments showed that compared with WT,chr12 chr23 double mutant rosette leaves had obvious anthocyanin accumulation,lower ROS and stronger antioxidant enzyme activities after drought stress.These results suggest that CHR12 and CHR23 may be involved in the negative regulation of drought tolerance in Arabidopsis thaliana.4.Through the analysis of stomata in leaf epidermis,it was found that the stomata of chr12 chr23 double mutants were much smaller than that of WT,and the expression of MPK3,MPK6,YDA and TMM related to stomatal development in double mutants was significantly higher than that of WT,so we speculated that CHR12 and CHR23 might affect stomatal development by negatively regulating the expression levels of MPK3,MPK6,YDA and TMM.5.The results of ABA sensitivity analysis showed that compared with WT,chr12chr23 double mutants were more sensitive to ABA,and ABA induced the expression of CHR12 and CHR23.At the same time,we also speculated that the complete deletion mutations of CHR12 and CHR23 may induce ABA synthesis and respond to the expression of related genes,and inhibit the expression of ABA catabolism related genes,so as to accumulate ABA in vivo and improve the tolerance of chr12 chr23 double mutants to drought and osmotic stress.6.Quantitative analysis showed that the complete deletion mutations of CHR12 and CHR23 may also improve the drought resistance of Arabidopsis thaliana by upregulating the expression levels of CPK11,Di19 and PR series genes related to drought.7.The transcriptome results showed that 2186 differentially expressed genes were associated with CHR12 and CHR23 in drought stress response,indicating that CHR12 and CHR23 play an important role in drought stress response.At the same time,we also found some interesting pathways,such as DNA replication,mismatch repair,nucleotide excision repair,plant-pathogen interaction and so on,which are related to CHR12 and CHR23.8.According to the phenotype of temperature stress,qPCR and BiFC experiments,CHR12 and CHR23 may participate in the response process of low temperature stress through interaction with ICE1 and CBF1,while CHR12 and CHR23 may also participate in the response process of high temperature stress through interaction with A1 D and HSFA3.It is found that the phenotype of chr12 chr23 double mutants can be restored,and CHR12 and CHR23 may be involved in the response to drought and temperature stress,which is helpful for us to further understand the ATP enzyme of chromatin remodeling complex.