Silencing Proline Dehydrogenases Improves Salt and Drought Tolerance in Gossypium hirsutum

Abstract

ABSTRACT Proline is a key compound that reduces cellular water potential, scavenges reactive oxygen species, and stabilizes biomolecules and cell membranes, thereby mitigating stress-induced damage. Proline dehydrogenase ( ProDH ), a rate-limiting enzyme in proline catabolism, acts as a critical negative regulator of proline accumulation. In this study, we explored the roles of the GhProDH gene family in regulating physiological responses to abiotic stress through integrated transcriptomic, metabolomic, and functional analyses. We characterized the GhProDH2 gene family in cotton and identified GhProDH2-4 as a central regulator of drought and salt tolerance. Functional analyses demonstrated that GhProDH2-4 negatively regulates stress tolerance; its overexpression in Arabidopsis increased stress sensitivity, whereas its silencing in cotton via virus-induced gene silencing (VIGS) enhanced resistance to both stresses. Integrated transcriptomic and metabolomic analyses further revealed that GhProDH2-4 modulates stress adaptation through carbon metabolism, the glyoxylate cycle, and flavonoid biosynthesis. These findings underscore the potential of fine-tuning proline degradation via GhProDH2-4 to improve cotton resilience under abiotic stress.

The authors' abstract, as published at the source. Plant Stress, 2026 · DOI ↗