The study investigates the role of galactinol and raffinose in protecting plants from oxidative damage. Galactinol synthase (GoLS) is crucial for the synthesis of raffinose family oligosaccharides (RFOs), which function as osmoprotectants in plant cells. Overexpression of heat shock transcription factor A2 (HsfA2) in Arabidopsis plants significantly increased the expression of GoLS and raffinose synthase genes, leading to higher levels of galactinol and raffinose. These plants showed increased tolerance to oxidative stress caused by methionol treatment and salinity or chilling stress. Galactinol and raffinose were found to protect salicylate from attack by hydroxyl radicals in vitro, suggesting that they may scavenge hydroxyl radicals as a novel function to protect plant cells from oxidative damage. The findings indicate that galactinol and raffinose play a significant role in protecting plants from various environmental stresses by acting as antioxidants and osmoprotectants.The study investigates the role of galactinol and raffinose in protecting plants from oxidative damage. Galactinol synthase (GoLS) is crucial for the synthesis of raffinose family oligosaccharides (RFOs), which function as osmoprotectants in plant cells. Overexpression of heat shock transcription factor A2 (HsfA2) in Arabidopsis plants significantly increased the expression of GoLS and raffinose synthase genes, leading to higher levels of galactinol and raffinose. These plants showed increased tolerance to oxidative stress caused by methionol treatment and salinity or chilling stress. Galactinol and raffinose were found to protect salicylate from attack by hydroxyl radicals in vitro, suggesting that they may scavenge hydroxyl radicals as a novel function to protect plant cells from oxidative damage. The findings indicate that galactinol and raffinose play a significant role in protecting plants from various environmental stresses by acting as antioxidants and osmoprotectants.