Arabidopsis Histone Methyltransferase SUVH5 Is a Positive Regulator of Light Mediated Seed Germination
Plant lifecycle starts from seed germination, which is regulated by various environmental cues and endogenous hormones. Light promotes seed germination mainly by phytochrome B (PHYB) during the initial phase of imbibition, which involves genome wide light responsive transcription changes. Recent studies indicated an involvement of multiple epigenetic factors in the control of seed germination. However, few studies have been reported about the role of a histone methyltransferase in light mediated seed germination process. Here, we identified SUVH5, a histone H3 lysine 9 methyltransferase, as a positive regulator in light mediated seed germination in Arabidopsis. Loss of function of SUVH5 leads to decreased PHYB dependent seed germination. RNA sequencing analysis displayed that SUVH5 regulates 24.6% of light responsive transcriptome in imbibed seeds, which mainly related to hormonal signaling pathways and developmental processes. Furthermore, SUVH5 represses the transcription of ABA biosynthesis and signal transduction related genes, as well as a family of DELAY OF GERMINATION (DOG) genes via dimethylation of histone H3 at lysine 9 (H3K9me2) in imbibed seeds. Taken together, our findings revealed that SUVH5 is a novel positive regulator of light mediated seed germination in Arabidopsis.
Front. Plant Sci.