Metabolic enhancement of glutathione biosynthesis via StGCL overexpression reduces acrylamide formation and improves salinity and osmotic stress resilience in potato tubers

Acrylamide is a carcinogenic compound formed during high-temperature processing of carbohydrate-rich foods such as potato chips and fries, primarily through the Maillard reaction between reducing sugars and the amino acid asparagine. Traditional strategies for acrylamide mitigation often target precursor pathways but remain insufficient for ensuring long-term food safety without compromising tuber quality. In this study, we investigated the role of glutamate cysteine ligase (StGCL), a key enzyme in the glutathione biosynthesis pathway, in reducing acrylamide formation in potato through overexpression. Glutathione, a ubiquitous antioxidant tripeptide, is known to conjugate with acrylamide or its reactive intermediates, thereby reducing their toxic potential. StGCL-overexpressing lines were generated via Agrobacterium-mediated transformation and confirmed through molecular analyses. Quantitative RT-PCR revealed significant upregulation of StGCL transcript levels in overexpressing lines compared to the wild-type. Biochemical assays demonstrated elevated glutathione content in the overexpression lines. Upon high-temperature frying, StGCL-overexpressing tubers accumulated significantly lower levels of acrylamide than their wild-type counterparts, with reductions of up to 60% in certain lines. These findings highlight the first in-planta strategy for acrylamide mitigation in potato by enhancing endogenous detoxification pathways and pave the way for developing safer potato cultivars with improved processing quality.