Open AccessBuilding a cluster of NLR genes conferring resistance to pests and pathogens: the story of the Vat gene cluster in cucurbits
Author(s) -
Véronique Chovelon,
Rafael Feriche-Linares,
Guillaume Barreau,
Joël Chadœuf,
Caroline Callot,
Véronique Gautier,
MarieChristine Le Paslier,
Aurélie Berad,
Patricia Faivre-Rampant,
Jacques Lagnel,
Nathalie Boissot
Publication year - 2021
Publication title -
horticulture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 31
eISSN - 2662-6810
pISSN - 2052-7276
DOI - 10.1038/s41438-021-00507-0
Subject(s) - biology , cucumis , melon , citrullus lanatus , genetics , gene , gene duplication , gene family , phylogenetics , genome , botany , horticulture
Most molecularly characterized plant resistance genes (R genes) belong to the nucleotide-binding-site-leucine-rich-repeat (NLR) receptor family and are prone to duplication and transposition with high sequence diversity. In this family, the Vat gene in melon is one of the few R genes known for conferring resistance to insect, i.e., Aphis gossypii , but it has been misassembled and/or mispredicted in the whole genomes of Cucurbits. We examined 14 genomic regions (about 400 kb) derived from long-read assemblies spanning Vat -related genes in Cucumis melo , Cucumis sativus, Citrullus lanatus, Benincasa hispida, Cucurbita argyrosperma , and Momordica charantia . We built the phylogeny of those genes. Investigating the paleohistory of the Vat gene cluster, we revealed a step by step process beginning from a common ancestry in cucurbits older than 50 my. We highlighted Vat exclusively in the Cucumis genera, which diverged about 20 my ago. We then focused on melon, evaluating a minimum duplication rate of Vat in 80 wild and cultivated melon lines using generalist primers; our results suggested that duplication started before melon domestication. The phylogeny of 44 Vat-CDS obtained from 21 melon lines revealed gain and loss of leucine-rich-repeat domains along diversification. Altogether, we revealed the high putative recognition scale offered in melon based on a combination of SNPs, number of leucine-rich-repeat domains within each homolog and number of homologs within each cluster that might jointly confer resistance to a large pest and pathogen spectrum. Based on our findings, we propose possible avenues for breeding programs.