Single nucleotide polymorphisms in the allene oxide synthase 2 gene are associated with field resistance to late blight in populations of tetraploid potato cultivars.

Abstract

The oomycete Phytophthora infestans causes late blight, the most relevant disease of potato (Solanum tuberosum) worldwide. Field resistance to late blight is a complex trait. When potatoes are cultivated under long day conditions in temperate climates, this resistance is correlated with late plant maturity, an undesirable characteristic. Identification of natural gene variation underlying late blight resistance not compromised by late maturity will facilitate the selection of resistant cultivars and give new insight in the mechanisms controlling quantitative pathogen resistance. We tested 24 candidate loci for association with field resistance to late blight and plant maturity in a population of 184 tetraploid potato individuals. The individuals were genotyped for 230 single nucleotide polymorphisms (SNPs) and 166 microsatellite alleles. For association analysis we used a mixed model, taking into account population structure, kinship, allele substitution and interaction effects of the marker alleles at a locus with four allele doses. Nine SNPs were associated with maturity corrected resistance (P < 0.001), which collectively explained 50% of the genetic variance of this trait. A major association was found at the StAOS2 locus encoding allene oxide synthase 2, a key enzyme in the biosynthesis of jasmonates, plant hormones that function in defense signaling. This finding supports StAOS2 as being one of the factors controlling natural variation of pathogen resistance.

• Authors: Karolina Pajerowska-Mukhtar, Benjamin Stich, Ute Achenbach, Agim Ballvora, Jens Lübeck, Josef Strahwald, Eckhard Tacke, Hans-Reinhard Hofferbert, Evgeniya Ilarionova, Diana Bellin, Birgit Walkemeier, Rico Basekow, Birgit Kersten, Christiane Gebhardt
• Journal: Genetics (Genetics) Vol. 181 Issue 3 Pg. 1115-27 (Mar 2009) ISSN: 0016-6731 [Print] United States
• PMID: 19139145 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cyclopentanes
• Oxylipins
• jasmonic acid
• Intramolecular Oxidoreductases
• hydroperoxide isomerase

Topics

• Cyclopentanes (metabolism)
• Genetic Linkage
• Genotype
• Immunity, Innate (genetics)
• Intramolecular Oxidoreductases (genetics, metabolism)
• Oxylipins (metabolism)
• Phenotype
• Phytophthora infestans (physiology)
• Plant Diseases (genetics, parasitology)
• Polymorphism, Single Nucleotide
• Solanum tuberosum (classification, enzymology, genetics, parasitology)