MtGlyI Is Necessary for Altering the GSH/GSSG Ratio in Response to Drought Tolerance.
(A) The wild-type (R108) plants and glyI mutants (glyI-1 and glyI-2) were subjected to three cycles of drought stress by withholding the water supply for 12, 14, and 14 d, respectively. Seedlings were photographed when the leaves of mutants exhibited primary wilting (ii). The mock plants were watered once a week, according to standard procedure (i).
(B) The survival rate of the plants in (A), ii. The mean values and se were calculated from three independent experiments. The asterisk indicates a significant difference between glyI mutants and wild-type plants (Kruskal-Wallis nonparametric test, **P < 0.01).
(C) The GSH/GSSG ratio of glyI mutants and wild-type plants under PEG-imposed dehydration stress. Total glutathione (GSH+GSSG) and GSSG were measured in glyI mutants and wild-type plants under 50% PEG-8000 treatment for 0, 0.5, 1, 2, and 4 h. The error bars represent the se of two samples. The asterisk indicates a significant difference between glyI mutants and wild-type plants under PEG-imposed dehydration stress (Kruskal-Wallis nonparametric test, **P < 0.01).