Impact of Exogenous BL on Drought Stress Tolerance of S. Miltiorrhiza at Different Growth Stages

To investigate the impact of exogenous BL on S. Miltiorrhiza during different growth phases under drought stress, plants of various ages were subjected to leaf surface spraying of BL with varying concentrations. As depicted in Fig. 1, all drought-stressed plants exhibited varying degrees of wilting after 21 days of treatment. Notably, in the 2M experimental group, plants treated with 0.5 μg/mL concentration BL (2MT2) demonstrated significant stress resistance. Likewise, in the 5M and 7M groups, plants treated with 1.0 μg/mL concentration BL (5MT3) and 2.0 μg/mL concentration BL (7MT4) respectively, exhibited the highest stress resistance.