PREPRINT | Tomato genomic regions and candidate genes linked to responses to a resistance inducer against Phytophthora infestans

This article is a preprint and has not been certified by peer review

Sangaré, A., Massire, A., Bourgeay, J-F., Gaucher, M., Duffaud, M., Pelpoir, E., Causse, M., Bardin, M., Caromel, B. Tomato genomic regions and candidate genes linked to responses to a resistance inducer against Phytophthora infestans. Research Square. https://doi.org/10.21203/rs.3.rs-10650999

Abstract:  Plant resistance inducers (PRIs) represent a promising and sustainable strategy for pest and disease management, but their efficacy can vary depending on plant genotype. Our objective was to identify the genetic architecture underlying tomato responses to the application of a PRI. We have established that Belvine® is an effective PRI against tomato late blight caused by Phytophthora infestans. Analysis of defense-related gene expression revealed that PR proteins, oxidative stress-related, and ethylene-associated genes were upregulated in Belvine®-treated plants. A Genome Wide Association Study panel of 148 tomato accessions was grown under plastic tunnel either treated with Belvine® or left untreated, then inoculated with P. infestans. We identified five quantitative trait loci (QTLs) associated with genotypic variation in Belvine® efficacy, located on chromosomes 2, 3, 4, and 12. Within the significant regions, we identified several candidate genes, including protein kinases, receptor-like protein kinases, transcription factors, and PR proteins. Notably, several candidate genes encoded proteins with functions analogous to those of genes upregulated under Belvine® treatment, including β‑1,3‑glucanases, glutathione S‑transferase, and peroxidase, even though they may correspond to distinct copies of these gene families. The identified QTL regions and candidate genes constitute valuable genomic resources for defining tomato breeding strategies aimed at enhancing plant responses to PRIs.