Fig. 1.

L-methionine (L-Met) promotes seed germination in Arabidopsis. (A) Seed germination at various concentrations of L-Met in the growth medium. Wild-type seeds were sown on half-strength MS medium supplemented with the indicated amounts of L-Met and incubated in the dark at 4 °C for 3 d before being transferred to a growth chamber at 22 °C for 36 h. (B) Germination phenotypes in the presence or absence of 30 µM L-Met at 36 h in the growth chamber. Representative images from three biological replicates are shown. Scale bars are 0.5 mm. (C) Time-course of seed germination in the presence or absence of L-Met (30 µM). Seeds were sown as described in (A) and incubated at 22 °C. (D) Effect of the Ca²⁺-channel blocker LaCl₃ on Met regulation of seed germination. Seeds were incubated on half-strength MS medium (control) or on medium supplemented with L-Met (10 µM), or L-Met (10 µM) plus LaCl₃ (100 µM or 200 µM) for 36 h and scored for germination. Data in (A, C, D) are means (±SE) from three independent replicates. Significant differences were determined using Student’s t-test: *P<0.05, **P<0.01. (This figure is available in colour at JXB online.)