The loss of GOX1 and GOX2 function differentially modulates proteomic reprogramming in response to short-term...

Salt stress is a major environmental constraint limiting plant growth and development. Although it induces significant changes in the plant proteome, the regulatory mechanisms underlying these responses remain poorly understood. In this study, a Tandem Mass Tag (TMT)-based proteomic approach was used to investigate the role of glycolate oxidases (GOX1 and GOX2) in regulating the shoot proteome of Arabidopsis thaliana under short-term salt stress. Wild-type (WT) plants and two T-DNA insertion mutants, gox1 and gox2, were exposed to salt treatment for 24h. A total of 3,607 non-redundant proteins were identified. Differentially accumulated proteins (DAPs) analysis revealed genotype-specific responses, with 47, 46, and 111 DAPs identified in WT, gox1, and gox2 plants, respectively. In WT plants, most DAPs were associated with defense and stress responses. The gox1 mutant showed over-accumulation of defense-related proteins and under-accumulation of transport proteins, suggesting an enhanced protective response. In contrast, gox2 exhibited coordinated changes in proteins involved in defense, transport, metabolism, protein turnover, and photosynthesis, indicating greater metabolic adaptability. These findings highlight the critical role of glycolate oxidase activity in modulating proteome remodeling under short-term salt stress and suggest that gox2 has enhanced capacity to maintain metabolic balance and stress resilience.