Fig. 6

The morphology of WT and OsPT4 mutants germinating seeds and seedlings’ leaf blade outgrowth status. A Longitudinal visual field of paraffin section of WT and OsPT4 mutant seeds 3 d after germination. Bar = 1000 μm. B The aleurone layer of WT and OsPT4 mutant seeds 3 d after germination. Bar = 500 μm. C and D Aleurone layer thickness (C) and density of aleurone layer cells (D). E Visualization of programmed cell death signals during seed germination. TUNEL assay were used to detect the nuclear DNA degradation in aleurone layer of NP and ospt4-1 mutant. The red arrow indicates the degradation of nuclear DNA. DAPI: 4′,6-diamidino-2-phenylindole, nuclear staining (deep blue); FITC: Fluorescein isothiocyanate isomer (green); Merged: indicating the apoptotic cell (wathet blue). F leaf outgrowth status of WT and OsPT4 mutant seedlings. Bar = 50 μm. Seedlings with the outgrowth of coleoptiles or different numbers of leaves were counted in (F) at each time point. Co, coleoptiles; 1st, 2nd, and 3rd represent the first, second, and third leaves, respectively. Values are means ± SE (n = 10) in (A–E) and 3 biological repeats in (F), different letters on the histograms indicate that the values differ significantly (*P < 0.05; **P < 0.01; Student’s t-test)