Abstract
Glutathione S-transferases (GSTs) are key enzymes in plant defences involved in detoxification, redox regulation, and the modulation of secondary metabolism, playing essential roles in the response to pathogen infections. Despite prior genome-wide predictions of GSTs in potato, little is known about their specific roles in defending against Spongospora subterranea. This study re-analyses our previously generated transcriptomics and proteomics datasets to explore the role of GSTs in two contrasting potato cultivars, 'Iwa' (susceptible) and 'Gladiator' (resistant), after inoculation with S. subterranea. A total of 69 and 41 GSTs were identified in the transcriptomics and proteomics data, respectively. The majority of these GSTs were upregulated in the resistant cultivar but not in the susceptible cultivar. The upregulation of GSTs in 'Gladiator' suggests a more efficient antioxidant and detoxification response following S. subterranea infection. Chromosomal mapping revealed a high number of GSTs on chromosome 9, suggesting a hotspot for GSTs in the potato genome. This research provides direct evidence of the potential involvement of GSTs in resistance to S. subterranea, offering insights into potential targets for breeding resistant potato cultivars.