Galactinol and raffinose are novel osmoprotectants that protect plants from oxidative damage. In Arabidopsis, overexpression of heat shock transcription factor A2 (HsfA2) increases the expression of galactinol synthase (GolS) and raffinose synthase (RS) genes, leading to higher levels of galactinol and raffinose. These compounds enhance tolerance to oxidative stress, such as treatment with methylviologen (MV), salinity, and chilling. Galactinol and raffinose effectively scavenge hydroxyl radicals, protecting plant cells from oxidative damage. The biosynthesis of raffinose family oligosaccharides (RFOs) involves galactinol, which is converted to raffinose by RS. RFOs accumulate in seeds and help in desiccation tolerance. Under stress conditions, RFOs are involved in protecting cellular structures and maintaining photosynthesis. Overexpression of GolS and RS genes increases intracellular levels of galactinol and raffinose, which act as antioxidants and osmoprotectants. These compounds help maintain cellular components and protect against oxidative damage caused by various environmental stresses. The study shows that galactinol and raffinose have a novel function as ROS scavengers, contributing to plant stress tolerance.Galactinol and raffinose are novel osmoprotectants that protect plants from oxidative damage. In Arabidopsis, overexpression of heat shock transcription factor A2 (HsfA2) increases the expression of galactinol synthase (GolS) and raffinose synthase (RS) genes, leading to higher levels of galactinol and raffinose. These compounds enhance tolerance to oxidative stress, such as treatment with methylviologen (MV), salinity, and chilling. Galactinol and raffinose effectively scavenge hydroxyl radicals, protecting plant cells from oxidative damage. The biosynthesis of raffinose family oligosaccharides (RFOs) involves galactinol, which is converted to raffinose by RS. RFOs accumulate in seeds and help in desiccation tolerance. Under stress conditions, RFOs are involved in protecting cellular structures and maintaining photosynthesis. Overexpression of GolS and RS genes increases intracellular levels of galactinol and raffinose, which act as antioxidants and osmoprotectants. These compounds help maintain cellular components and protect against oxidative damage caused by various environmental stresses. The study shows that galactinol and raffinose have a novel function as ROS scavengers, contributing to plant stress tolerance.