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United States Department of Agriculture

Agricultural Research Service

Research Project: Resources for the Genetic Improvement of Potato

Location: Vegetable Crops Research

Title: Verticillium dahliae disease resistance and the regulatory pathway for tuberization in potato

Author
item Halterman, Dennis
item Tai, Helen
item De Koeyer, David
item Sonderkaer, Mads
item Hedegaard, Sanne
item Lague, Martin
item Goyer, Claudia
item Nolan, Lana
item Davidson, Charlotte
item Gardner, Kyle
item Neilson, Jonathan

Submitted to: The Plant Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary: In this paper, we study the expression of genes in potato after inoculation with the fungal pathogen Verticillium dahliae. Genes that are differentially regulated (higher or lower expression) were located within the potato genome. One location of genes that corresponded with disease resistance was a region that encodes the Ve resistance gene, a gene that confers resistance to V. dahliae in tomato. We also identified a second location that contains the gene StCDF1 and other genes that work with StCDF1. St CDF1 is involved in several aspects of potato physiology, including activation of tuberization. The identification of both of these locations and their association with resistance to V. dahliae suggests that the two pathways may be involved in the potato’s response to infection with the pathogen.

Technical Abstract: Verticillium dahliae Kleb. is a pathogenic fungus causing wilting, chlorosis, and early dying in potato. Genetic mapping of resistance V. dahliae was done using a diploid population in potato. A quantitative trait locus (QTL) on chromosome 9 co-localized with the Ve2 Verticillium wilt resistance gene marker. Another major QTL was found on chromosome 5. The StCDF1 gene controlling maturity and tuberization was mapped within the interval. Epistasis analysis indicated that the two loci on chromosomes 5 and 9 had highly significant interaction, and that StCDF1 functioned downstream of Ve2. Expression QTL (eQTL) and Gene Ontology (GO) analyses identified genes at the StCDF1 and Ve2 loci with similar functions involving the chloroplast, including photosynthesis. However, differences were also noted. Among the GO terms that were specific to genes with eQTL at the Ve2, but not the StCDF1 locus, were associated with fungal defense. The expression of genes regulated by StCDF1 and functioning downstream in the pathway for regulation of maturity and tuberization were also genetically mapped. The mobile tuberigen, StSP6A, and the gene upstream of it, StSP5G, were found to have an eQTL on chromosome 5 at the same location as that found for V. dahliae resistance. Together these results suggest a correlation between gene pathways controlling maturity and tuberization and those involved in V. dahliae defense.

Last Modified: 09/24/2017
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