Fig. 5

Exogenous ABA priming improved grain yield in rice under heat stress. The rice plants were sprayed with distilled water, 50 μM ABA or 10 μM fluridone (FLU) at the 5th d after initial heading stage (AIH) or 12th d after initial heading stage, and then subjected to unstressed or heat stress conditions at 8–14 days after initial heading (AIH) stage or 15–21 days after initial heading stage, respectively. (A) Image of rice grain at the mature stage under different treatments. (B) Harvest index (HI, %) and (C) grain yield per plant (GY, g) were measured at the mature stage. Values are means ± SDs, n = 3. Different letters on the column represent significant differences (P < 0.05) between different treatments based on Duncan’s test