INO80 complex promotes thermomorphogenesis by integrating H2A.Z eviction and active transcription. Arabidopsis thaliana

Global warming imposes a major threat to plant growth and crop production.In some plants including Arabidopsis thaliana, elevated temperatures induce aseries of morphological and developmental adjustments, termedthermomorphogenesis to facilitate plant cooling under high-temperatureconditions. Plant thermal response is suppressed by histone variant H2A.Z. Atwarm temperatures, H2A.Z is evicted from nucleosomes at thermo-responsivegenes, resulting in their activation. However, the mechanisms that regulateH2A.Z eviction and subsequent transcription activation are largely unknown.Here, we show that the INO80 chromatin-remodeling complex (INO80-C)promotes thermomorphogenesis and activates the expression of thermoresponsiveand auxin-related genes. INO80-C associates withPHYTOCHROME-INTERACTING FACTOR 4 (PIF4), a potent regulator inthermomorphogenesis, and mediates temperature-induced H2A.Z eviction atPIF4 targets. Moreover, INO80-C directly interacts with COMPASS-like andtranscription elongation factors to promote active histone modification HistoneH3 lysine 4 trimethylation (H3K4me3) and RNA Polymerase II (RNA Pol II)elongation, leading to the thermal induction of transcription. Notably,transcription elongation factors are required for the H2A.Z eviction at PIF4targets, suggesting the cooperation of INO80-C and transcription elongation inH2A.Z removal. Our results demonstrate that the (PIF4)-(INO80-C)-(COMPASS-like)-(transcription elongator) module controls plant thermalresponse, and establish a link between H2A.Z eviction and activetranscription.