Figure 7.

Expression patterns of SlSRs in response to drought stress and ABA treatment and phenotypes of the SlSRs -silenced plants under drought condition. (A) Expression of SlSRs in detached leaves under drought stress. Fully expanded leaves were detached from four-week-old plants and subjected to drought stress treatment by placing on lab blench or water-saturated filter papers in Petri dishes as a control and samples were collected at different time points as indicated. (B) Expression of SlSRs in detached leaves after ABA treatment. Four-week-old plants were treated by foliar spraying with ABA solution (100 μM) or water as control and leaf samples were collected at different time points as indicated. Relative expression levels of the SlSR genes in the treated plants were shown as folds of the expression levels in the control plants after normalization with actin transcript values. (C) and (D) Expression of SlSRs in leaves of plants under drought stress. Four-week-old plants were treated for drought stress by stopping watering for a period or watered normally as controls and leaf samples were collected at 7 days after treatment when wilting symptom appeared (C). Total RNA was extracted and used for qRT-PCR analysis of expression of SlSRs (D). Relative expression levels of the SlSR genes in the treated and control plants were shown as folds of the actin transcript values. (E) Phenotypes of the SlSRs-silenced plants under drought condition. Two-week-old seedlings were infiltrated with agrobacteria carrying pTRV2-SlSRs or pTRV2-GUS constructs and 3 weeks later the pTRV2-GUS- and pTRV2-SlSRs-infiltrated plants were subjected to drought stress by stopping watering for 10 days. Data presented in (A), (B) and (D) are the means ± SD from three independent experiments and different letters above the columns in (D) indicate significant difference at p < 0.05 level.