Trehalose application mitigates drought stress in by enhancing photosynthesis, antioxidant activity, and osmolyte production in sugar beet (Betus vulgaris)

Trehalose is a naturally occurring and non-toxic disaccharide, and has been recognised for its role in mitigating abiotic stress in various plant species. However, its potential to enhance drought resistance in sugar beet (Beta vulgaris) remains unexplored. This study evaluated the effects of exogenous trehalose application on sugar beet seedlings subjected to drought stress. Trehalose solutions at concentrations of 5, 10, 15, 20, and 30 mM were applied foliarly during the stress period. Drought stress markedly reduced key growth and physiological parameters, including dry and fresh biomass, leaf relative water content, root area, leaf area, plant height, chlorophyll content, and root activity, while increasing oxidative stress markers such as superoxide anion and malondialdehyde levels. Among the treatments, 20 mM trehalose notably alleviated these adverse effects by improving physiological and biochemical traits. Specifically, it enhanced net photosynthetic rate (Pn), antioxidant enzyme activity, and regulated osmolyte accumulation. These findings suggest that trehalose application can effectively improve sugar beet resilience to drought, offering a promising approach for optimizing sugar beet cultivation in water-limited environments.