Drought Stress Response Escalates with Plant Height in a Size-Dependent Manner

Plant height plays a crucial role in drought stress response, with taller plants exhibiting heightened sensitivity. Our research demonstrates a clear size-dependent pattern in the extent of drought-induced damage and the efficacy of mitigating measures. Specifically, we observed that the increase in malondialdehyde (MDA) levels, a marker of oxidative stress, was most pronounced in plants shorter than 3m, followed by those shorter than 5m, and least pronounced in plants shorter than 7m. This suggests a progressive increase in drought susceptibility with decreasing plant height. Furthermore, the application of exogenous betaine lipid (EBL) revealed a similar trend in its ability to alleviate membrane lipid peroxidation, a key manifestation of drought stress. EBL's protective effect was most pronounced in the shortest plants and gradually diminished with increasing plant height. This study underscores the importance of considering plant size as a critical factor influencing drought stress responses and highlights the potential of EBL as a mitigant, particularly in smaller plants.