Fig. 3.
Enhanced drought tolerance in BiP-overexpressing soybean lines exposed to a 7 d suspension of watering. (A) Water stress-tolerant phenotype of transgenic lines. Water stress conditions were induced in wild type, 35S:BiP-2, and 35S:BiP-4 transgenic lines at the V3 developmental stage by withholding irrigation for 7 d when the plants were photographed. (B) Relative water content of wild-type and transgenic leaves. The relative water content of normally irrigated plants (I) and drought-stress plants (DS) was measured on the 7th day of experiment. The asterisk indicates significant differences at P ≤0.05 as compared to the wild type. (C, D, E) Physiological measurements of soybean transgenic lines continuously irrigated (I) or exposed to drought stress (DS). Photosynthetic rate (C), stomatal conductance (D), and transpiration rate (E) of the third fully expanded leaf of WT and 35S:BiP-4 lines were measured by the LI-6400 infrared (IR) gas analyser at 1000 μmol m−2 s−1 irradiance during the period of the experiment. Values represent the mean ±SD of three replicates.