Fig. 1.
GLs exploited as a sulfur source in Arabidopsis thaliana. (A) Potential sulfur reallocation by GL–myrosinase system. Two sulfur atoms common in GL molecules are donated from GSH (yellow) and 3′-phosphoadenosine-5′-phosphosulfate (PAPS, orange) during biosynthesis. Hydrolysis of GLs by myrosinases, which may include BGLU28 and BGLU30, triggers generation of SO42-, a major sulfur source in plants. (B–F) Exogenous GL as the sole sulfur source rescued the growth of Col-0 seedlings under sulfur-deficient conditions. (B) Images of 14-d-old seedlings cultured at S1500, S150, and S0 conditions (1,500, 150, and 0 μM SO42-, respectively) or S0 with 150 μM 4MSB used in the following analysis. (C and D) Dry weights of the 14-d-old seedlings as the sum of 10 plants cultured at different sulfur concentrations with or without 4MSB (C, n = 11) or with different GL species supplied at 150 μM under S0 condition (D, n = 6). (E and F) Relative contents of Cys in plant tissues. n = 5 in E, and n = 6 in F. Point shapes indicate individual experimental batches. Letters indicate statistical significance corresponding to two-tailed t tests based on an LMM with batches as a random factor, followed by a correction for multiple comparisons controlling false discovery rate (P < 0.05). Abbreviations of GLs correspond to those listed in Table 1.