Harnessing Genomics and Transcriptomics to Combat PVY Resistance in Potato: From Gene Discovery to Breeding Applications

Abstract

Potato virus Y (PVY) is a major threat to global potato production, causing yield losses of nearly 90%. This emphasizes the urgent need to explore the genetic factors underlying resistance mechanisms. Developments in transcriptomics and plant genomes have shed significant light on the genetic underpinnings of PVY resistance. This review summarizes current knowledge on PVY biology and structure, its impacts, key hypersensitive resistance (HR) and extreme resistance (ER) genes and their associated molecular markers, genomic strategies for discovering resistance genes and improving resistance breeding, and challenges. Genetic resistance is a key strategy for controlling PVY, primarily through HR and ER, which are governed by specific genes: the Ny gene for HR and the Ry gene for ER. Our understanding of the molecular mechanisms underlying this resistance has increased significantly due to the advancement of high-throughput sequencing methods, including RNA and whole-genome sequencing. More than 10 PVY resistance genes have been identified in potato, including well-characterized ER genes such as Rysto, Ry-fsto, Ryadg, Rychc, and Ry(o)phu, as well as HR genes such as Ny-1, Ny-2, and Ny-Smira, which are discussed in this review. Transcriptomic analyses have revealed the involvement of small RNAs and other regulatory molecules in modulating resistance responses. Transcriptomic studies have also identified 6071 differentially expressed genes (DEGs) in potato cultivars infected with PVY, highlighting strong defense responses influenced by strain, cultivar, and environmental conditions. The identification of these resistance genes facilitates the development of PVY-resistant cultivars through marker-assisted selection and gene pyramiding, offering significant opportunities to enhance PVY management and promote sustainable potato production under the challenges posed by climate change.