Fig. 3

The effect of overexpression of sha-miR319d on the chlorophyll content and Fv/Fm. a Chlorophyll content of WT and transgenic plants under control or chilling (4 °C) treatment for 5 d. b Chlorophyll content of WT and transgenic plants under control or heat (40 °C) treatment for 5 d. C Fv/Fm of WT and transgenic plants under chilling (4 °C) treatment. d Fv/Fm of WT and transgenic plants under heat (40 °C) treatment. T2 generations of transgenic plants as well as the WT were used for measurements of Fv/Fm and the chlorophyll content. The data in (a) and (b) are the mean of three biological repeats ± the standard deviation (SD). Asterisks indicate significant differences between transgenic lines and WT. *, P < 0.05; **, P < 0.01, Student’s t test. The data in (c) and (d) are the means ± the standard deviation (SD) obtained from 24 seedlings, and letters above indicate the statistical significance of differences (P < 0.05) analyzed by variance (ANOVA) using SPSS 18.0