The chromatin remodeling complex imitation of switch controls stamen filament elongation by promoting jasmonic acid biosynthesis in Arabidopsis.

Plant reproduction requires the coordinated development of both male and female reproductive organs. Jasmonic acid (JA) plays an essential role in stamen filament elongation. However, the mechanism by which the JA biosynthesis genes are regulated to promote stamen elongation remains unclear. Here, we show that the chromatin remodeling complex Imitation of Switch (ISWI) promotes stamen filament elongation by regulating JA biosynthesis. We show that AT-Rich Interacting Domain 5 (ARID5) interacts with CHR11, CHR17, and RLT1, several known subunits of ISWI. Mutations in ARID5 and RLTs caused a reduced seed set due to greatly shortened stamen filaments. RNA-seq analyses reveal that the expression of key genes responsible for JA biosynthesis is significantly down-regulated in the arid5 and rlt mutants. Consistently, the JA levels are drastically decreased in both arid5 and rlt mutants. Chromatin immunoprecipitation-quantitative PCR analyses further show that ARID5 is recruited to the chromatin of JA biosynthesis genes. Importantly, exogenous JA treatments can fully rescue the defects of stamen filament elongation in both arid5 and rlt mutants, leading to the partial recovery of fertility. Our results provide a clue how JA biosynthesisis positively regulated by the chromatin remodeling complex ISWI, thereby promoting stamen filament elongation in Arabidopsis.