Title : The Arabidopsis Chromatin-Remodeling Factor ISWIs Regulates Plant Immune Responses
Chromatin remodeling ATPases regulate global gene expression by utilizing energy derived from ATP hydrolysis to alter nucleosome-DNA contacts in chromatin. There are 42 putative SNF2 ATPases in Arabidopsis, many of which have un-known functions. ISWIs (Imitation Switch) belong to ISWI subgroup chromatin remodeling ATPases which are evolutionarily conserved in plants and animals. The studies in yeast, drosophila and mammals have revealed that ISWIs are important for development and stress tolerance. In plants, the function of these proteins has not been analyzed except for in Arabidopsis where they play critical roles in development and nucleosome regulation. There are two ISWI genes CHROMATIN REMODELING 11 (CHR11) and CHR17 in Arabidopsis genome, which play an important role in the development of female gametophyte, flowering time and floral organ development. Moreover, Arabidopsis ISWI proteins have been proved to be able to regulate the evenly spaced nucleosome distribution pattern in the gene bodies at the whole genome level, and the above regulation has been proved to be related to gene expression. Although there have been some studies on the function of ISWI protein in Arabidopsis growth, development and nucleosome occupancy regulation, whether ISWI proteins participate in plant stress resistance regulation and whether there is a certain relationship between nucleosome arrangement and plant stress tolerance needs further study. We found that disease-related genes were significant up-regulated in double mutant chr11 chr17. Our recent study using ISWI mutants showed that the Arabidopsis ISWIs proteins were involved in the regulation of virulent pathogen Pseudomonos syringae pv. tomato DC3000 (Pst DC3000) resistance. Further, we found that the ISWIs-mediated resistance was related to salicylic acid(SA)-mediated signaling pathways.