The RdDM Pathway Is Required for Basal Heat Tolerance in Arabidopsis  

作　　者：Olga V. Popova Huy Q. Dinh Werner Aufsatz Claudia Jonak 

机构地区：[1]GMI-Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030 Vienna, Austria

出　　处：《Molecular Plant》2013年第2期396-410,共15页分子植物（英文版）

摘　　要：Heat stress affects epigenetic gene silencing in Arabidopsis. To test for a mechanistic involvement of epige-netic regulation in heat-stress responses, we analyzed the heat tolerance of mutants defective in DNA methylation, his-tone modifications, chromatin-remodeling, or siRNA-based silencing pathways. Plants deficient in NRPD2, the common second-largest subunit of RNA polymerases IV and V, and in the Rpd3-type histone deacetylase HDA6 were hypersensi- tive to heat exposure. Microarray analysis demonstrated that NRPD2 and HDA6 have independent roles in transcriptional reprogramming in response to temperature stress. The misexpression of protein-coding genes in nrpd2 mutants recover-ing from heat correlated with defective epigenetic regulation of adjacent transposon remnants which involved the loss of control of heat-stress-induced read-through transcription. We provide evidence that the transcriptional response to temperature stress, at least partially, relies on the integrity of the RNA-dependent DNA methylation pathway.Heat stress affects epigenetic gene silencing in Arabidopsis. To test for a mechanistic involvement of epige-netic regulation in heat-stress responses, we analyzed the heat tolerance of mutants defective in DNA methylation, his-tone modifications, chromatin-remodeling, or siRNA-based silencing pathways. Plants deficient in NRPD2, the common second-largest subunit of RNA polymerases IV and V, and in the Rpd3-type histone deacetylase HDA6 were hypersensi- tive to heat exposure. Microarray analysis demonstrated that NRPD2 and HDA6 have independent roles in transcriptional reprogramming in response to temperature stress. The misexpression of protein-coding genes in nrpd2 mutants recover-ing from heat correlated with defective epigenetic regulation of adjacent transposon remnants which involved the loss of control of heat-stress-induced read-through transcription. We provide evidence that the transcriptional response to temperature stress, at least partially, relies on the integrity of the RNA-dependent DNA methylation pathway.

关 键 词：heat stress RNA-directed DNA methylation TRANSPOSONS read-through transcription. 

分 类 号：Q943[生物学—植物学] Q51