摘要：SummaryPectin is biosynthesized in a highly methylated form and is partially de-methylated by pectin methylesterase (PME) activity. Plant PMEs play a critical role in cell wall remodeling in many physiological processes. Here, we studied Arabidopsis seedlings, which had been exposed to simulated or actual microgravity. Simulated microgravity inhibited total PME activity in Arabidopsis seedlings. We identified thatAtPMEPCRAexpression played a major role in the microgravity-induced inhibition of PME activity.atpmepcramutants did not exhibit the enlarged leaf area of Arabidopsis seedlings observed under spaceflight microgravity. The downregulation ofAtPMEPCRAexpression in response to microgravity was due, in part, to changes in methylation patterns. The sexual offspring of the plants grown during spaceflight retained the methylation changes atAtPMEPCRAlocus for one generation and thus contribute to the physiological adaptation to microgravity among F1offspring seed generation. We conclude thatAtPMEPCRAcontributes to the spaceflight-induced transgenerational responses in Arabidopsis.Graphical abstractDisplay OmittedHighlights•Simulated microgravity inhibited total PME activity in Arabidopsis seedlings•AtPMEPCRAplayed a major role in the microgravity-induced inhibition of PME activity•atpmepcramutants did not exhibit the enlarged seedlings leaf area observed under microgravity•AtPMEPCRA regulates the spaceflight-induced transgenerational responses in ArabidopsisBiological sciences; Plant biology; Plant physiology; Space sciences
