Fig. 7: PSI-m6A stabilizes PHR1 transcripts to facilitate PSI signaling.
a Profile of PHR1 transcript decay showing its decreased half-life in amiR-mta compared with the WT under −P conditions. The relative RNA abundance following the inhibition of transcription is shown, with bars indicating the means ± SE, n = 3; thick lines indicate modeled values. The half-life (t1/2) of PHR1 is indicated for each genotype. b Diagram of self-promoter-driven and Flag-4Myc (FM)-tagged genomic PHR1 with WT and m6A-loci-mutated 3′ UTR. The seven putative m6A loci and corresponding mutants are shown. The numbers indicate the positions of the mutated A, counted from the first nucleotide of the 3′ UTR. c PHR1-FM expression is significantly reduced in PHR1-MUT compared to PHR1-WT transgenic plants, while the expression of the control gene Basta is unchanged. d Images of 14-day-old WT, phr1, PHR1-WT, and PHR1-MUT seedlings after seven days of growth under Pi-deficient conditions (−P). The PHR1-MUT and phr1 mutant, but not PHR1-WT, accumulated less anthocyanin than the WT. e Anthocyanin contents in PHR1-MUT and PHR1-WT shoots under −P conditions. f RT-qPCR analysis of the expression of genes downstream of PHR1 (ACP5 and PHF1) in PHR1-MUT and PHR1-WT under −P conditions. g Target-specific RNA decay of the half-life of PHR1-FM in PHR1-MUT and PHR1-WT under −P conditions. The relative expression levels of transcripts were normalized to those at the 0 h time point, where the ratio was arbitrarily set to 1 with SD calculated from three biological repeats. h Model of the role of PHR-mediated PSI-m6A modifications in stabilizing PSR-related transcripts to facilitate plant adaptation to stress. In (c, e, f, and g), *P < 0.05; **P < 0.01, as determined using an unpaired two-tailed Student’s t-test; n.s. indicates not significant. In (c, e, f), the midlines and box edges indicate the medians and quartiles, respectively. The whiskers extend to the farthest data point within 1.5 times the IQR from the box edges. In (c and f), data from three individual transgenic lines with three technical repeats per line are shown. In (e), a total of nine biological repeats from three individual PHR1-WT lines and a total of eight biological repeats from three individual PHR1-MUT lines are shown. Source data are provided as a Source Data file.
