PHOSPHORYLETHANOLAMINE CYTIDYLYLTRANSFERASE 1 modulates flowering in a florigen-independent manner by regulating .

PHOSPHORYLETHANOLAMINE CYTIDYLYLTRANSFERASE 1 (PECT1) regulates phosphatidylethanolamine biosynthesis and controls the phosphatidylethanolamine:phosphatidylcholine ratio in Previous studies have suggested that PECT1 regulates flowering time by modulating the interaction between phosphatidylcholine and FLOWERING LOCUS T (FT), a florigen, in the shoot apical meristem (SAM). Here, we show that knockdown of by artificial microRNA in the SAM () accelerated flowering under inductive and even non-inductive conditions, in which transcription is almost absent, and in double mutants under both conditions. Transcriptome analyses suggested that PECT1 affects flowering by regulating () and (). misexpression in the SAM suppressed the early flowering of plants. plants showed increased gibberellin (GA) levels in the SAM, concomitant with the reduction of REPRESSOR OF GA1-3 levels. Consistent with this, GA treatment had little effect on flowering time of plants and the GA antagonist paclobutrazol strongly affected flowering in these plants. Together, these results suggest that PECT1 also regulates flowering time through a florigen-independent pathway, modulating expression and thus regulating GA production.