Fig. 4

Drought tolerance of wild-type (WT, cv. Dongjin) and osnadk1 mutant plants. a Phenotypes of WT and osnadk1 rice plants under drought conditions, including before drought treatment (left image), without watering for 10 days (middle image), and re-watering after 1 week (right image). Four-week-old plants were used for the drought treatments. b Water loss percentage in detached leaves of WT and osnadk1 mutant plants. Values represent the mean ± SD of 3 replicates (9 leaves from one pot per replicate), and three experiments were performed with similar results. c Survival rate of WT and osnadk1 mutant plants under drought conditions. d Comparison of the relative expression levels of OsNADK1 in the WT and osnadk1 mutant under control and drought conditions. e Total NADK activity in leaf samples from the WT and osnadk1 mutant. Samples were collected from leaves without watering for 10 days and control samples. ** Represents significant differences by the t-test, and different letters above the bars represent significant differences by the Tukey method (P ≤ 0.05)