Fig. 4.

Root growth of soybean seedlings exposed to a low water potential. Wild type (WT) and BiP overexpressing (BiP-2 and BiP-4 lines) soybean seedlings were grown on MS solid medium in the absence (A) and presence of 1% PEG (B) for 4 weeks when the roots were photographed. In (C), the root dry weight of 4-week-old seedlings (WT and BiP-4) grown in MS medium supplemented with 1% (PEG1) or 2% PEG (PEG2) was measured. (D) Root length of plants exposed to a drying soil. Water stress conditions were imposed in wild-type and BiP-4 transgenic lines at the V3 developmental stage by withholding irrigation for 7 d. Root length was measured on day 7. I, normally irrigated; DS, drought-stressed plants. (E) Root dry weight of plants exposed to drought. Root dry weight was measured on the 9th day of water deprivation. Asterisks indicate significant differences at P ≤0.05.