EBL Enhances Proline Accumulation in Salvia miltiorrhiza under Drought Stress

Exogenous application of betaine aldehyde (EBL) significantly enhanced proline accumulation in Salvia miltiorrhiza plants subjected to drought stress. This effect was observed across three distinct developmental stages (2M, 5M, and 7M). In 2M plants, EBL concentrations of 1M, 2M, and 5M led to significant increases in proline content, with the most pronounced effect at 2M. Similarly, 5M plants exhibited increased proline levels at EBL concentrations of 3M, 4M, and 5M, with 3M eliciting the greatest response. Notably, in 7M plants, EBL concentrations of 4M, 7M, and 8M significantly elevated proline content, with the 7M concentration demonstrating optimal efficacy. These findings suggest a potential role for EBL in mitigating drought stress in Salvia miltiorrhiza by promoting proline accumulation.