Fig. 5.

Overexpression of SlDREB restricts tomato leaf expansion and internode elongation. (A) Phenotypic appearance of seedlings (upper) and leaves (lower) of SlDREB-overexpressing tomato OE4 and OE13 lines and WT plants. (B) Leaflet size of WT and SlDREB lines OE4 and OE13. The third leaf from the top of 2-month-old transgenic and non-transgenic plants was used for leaflet size measurement; the apical leaflet was chosen from the leaf. Error bar indicates SE (n=8). (C) Internode length of 2-month-old WT and SlDREB OE4 tomato plants. Error bars indicates SE (n=8). (D) Scanning electron microscopy images showing leaf thickness. Leaves were collected from 2-month-old tomato SlDREB-overexpressing and WT plants grown in a naturally illuminated glasshouse. The apical leaflet of the third leaf from the top was collected for analysis. (E) The expression level of SlDREB in transgenic and WT control plants was examined at the five-leaf stage by real-time PCR analyses. Error bars indicates SE (n=8). (F) Graphical representation of leaf thickness. Eight individual plants were selected per line and the thickness of every leaf was measured three times. Asterisks indicate significant differences compared with WT (**P < 0.01). (G) SlDREB-overexpressing plants show drought resistance. At 40 d post-inoculation, watering was stopped for drought treatment. The photographs were taken after 15 d. Treatment was replicated three times under the same conditions (n > 8). (H) The mean number of stomata per unit area in SlDREB overexpressing and WT leaves. Stomatal number was counted in each field of view (400×, ~0.065mm²) on at least 20 microscopes and three plants. The third leaf from the top of 2-month-old transgenic and non-transgenic plants was analysed. (This figure is available in colour at JXB online.)