Galactinol Synthase and Abiotic Stress Tolerance in Plants

Galactinol synthase (GolS) catalyses the first committed step in the biosynthesis of raffinose family oligosaccharides (RFOs), a class of sugars that accumulate in plants under drought, cold, salinity and oxidative stress. By transferring a galactosyl moiety from UDP-galactose to myo-inositol, GolS generates galactinol, which serves as a galactosyl donor for subsequent raffinose and stachyose synthesis. RFOs function as osmoprotectants, stabilising membranes, scavenging reactive oxygen species and maintaining cellular homeostasis during dehydration or temperature extremes. Expression of GolS genes is tightly regulated by stress-responsive transcription factors, including C-repeat binding factors and ethylene-responsive elements, and varies by tissue, developmental stage and species. Comparative genomics has revealed expansion and diversification of GolS gene families among legumes, cereals and oilseeds, informing the selection of promoters for targeted transgenic expression. Field trials of GolS‐engineered crops have demonstrated enhanced water-use efficiency, survival rates under frost and improved grain yield under drought, underscoring the global significance of manipulating the RFO pathway to safeguard food security in a changing climate.

Research from Nature Portfolio

In chickpea, two divergent GolS genes were shown to produce multiple isoforms through alternative splicing, with seed‐specific expression patterns that rise during maturation and artificial ageing. Transgenic plants overexpressing these isoforms exhibited enhanced seed vigour and longevity through reduced lipid peroxidation and lower accumulation of age-induced reactive oxygen species. Genome-wide analysis in sesame identified seven GolS and fifteen raffinose synthase genes, with several GolS members strongly upregulated by drought, osmotic and salinity stresses. Distinct expression profiles across tissues and developmental stages pointed to specialised roles of individual gene family members in desiccation tolerance of seeds and vegetative organs.

Galactinol Synthase and Abiotic Stress Tolerance in Plants publication trend

The graph below shows the total number of articles in galactinol synthase and abiotic stress tolerance in plants across all publications each year (not limited to Nature Index journals).

Technical terms

Galactinol synthase (GolS): Enzyme that catalyses the formation of galactinol from UDP-galactose and myo-inositol, initiating the raffinose family oligosaccharide pathway.

Raffinose family oligosaccharides (RFOs): A group of oligosaccharides including raffinose and stachyose, which serve as osmoprotectants and reactive oxygen species scavengers in plants under stress.

Osmoprotectant: Small molecule that accumulates in cells to stabilise proteins and membranes and to maintain osmotic balance during abiotic stress.

Abiotic stress tolerance: The capacity of plants to resist or adapt to non-living environmental stresses such as drought, salinity, extreme temperatures and oxidative damage through physiological and molecular mechanisms.

References

1. Overexpression of galactinol synthase 1 from Solanum commersonii (ScGolS1) confers freezing tolerance in transgenic potato. Horticultural Plant Journal (2023).
2. Overexpression of an Arabidopsis thaliana galactinol synthase gene improves drought tolerance in transgenic rice and increased grain yield in the field. Plant Biotechnology Journal (2017).
3. Differentially expressed galactinol synthase(s) in chickpea are implicated in seed vigor and longevity by limiting the age induced ROS accumulation. Scientific Reports (2016).
4. Genome-wide identification and expression analyses of genes involved in raffinose accumulation in sesame. Scientific Reports (2018).
5. Significance of galactinol and raffinose family oligosaccharide synthesis in plants. Frontiers in Plant Science (2015).