Dataset Information

QTL mapping of insect resistance components of Solanum galapagense.

ABSTRACT:

Key message

QTLs for insect resistance parameters, trichome type IV development, and more than 200 non-volatile metabolites, including 76 acyl sugars, all co-locate at the end of Chromosome 2 of Solanum galapagense. Host plant resistance is gaining importance as more and more insecticides are being banned due to environmental concerns. In tomato, resistance towards insects is found in wild relatives and has been attributed to the presence of glandular trichomes and their specific phytochemical composition. In this paper, we describe the results from a large-scale QTL mapping of data from whitefly resistance tests, trichome phenotyping and a comprehensive metabolomics analysis in a recombinant inbred line population derived from a cross between the cultivated Solanum lycopersicum and the wild relative S. galapagense, which is resistant to a range of pest insects. One major QTL (Wf-1) was found to govern the resistance against two different whitefly species. This QTL co-localizes with QTLs for the presence of trichomes type IV and V, as well as all 76 acyl sugars detected and about 150 other non-volatile phytochemicals, including methyl esters of the flavonols myricetin and quercetin. Based on these results, we hypothesize that Wf-1 is regulating the formation of glandular trichome type IV on the leaf epidermis, enabling the production and accumulation of bioactive metabolites in this type of trichomes.

SUBMITTER: Vosman B

PROVIDER: S-EPMC6349790 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

QTL mapping of insect resistance components of Solanum galapagense.

Vosman Ben B Kashaninia Atiyeh A Van't Westende Wendy W Meijer-Dekens Fien F van Eekelen Henriëtte H Visser Richard G F RGF de Vos Ric C H RCH Voorrips Roeland E RE

TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik 20181123 2

<h4>Key message</h4>QTLs for insect resistance parameters, trichome type IV development, and more than 200 non-volatile metabolites, including 76 acyl sugars, all co-locate at the end of Chromosome 2 of Solanum galapagense. Host plant resistance is gaining importance as more and more insecticides are being banned due to environmental concerns. In tomato, resistance towards insects is found in wild relatives and has been attributed to the presence of glandular trichomes and their specific phytoch ...[more]

PMID: 30470858

Similar Datasets

Project description:Identifying genetic sequences underlying insect associations on forest trees will improve the understanding of community genetics on a broad scale. We tested for genomic regions associated with insects in hybrid poplar using quantitative trait loci (QTL) analyses conducted on data from a common garden experiment. The F2 offspring of a hybrid poplar (Populus trichocarpa x P. deltoides) cross were assessed for seven categories of insect leaf damage at two time points, June and August. Positive and negative correlations were detected among damage categories and between sampling times. For example, sap suckers on leaves in June were positively correlated with sap suckers on leaves (P<0.001) but negatively correlated with skeletonizer damage (P<0.01) in August. The seven forms of leaf damage were used as a proxy for seven functional groups of insect species. Significant variation in insect association occurred among the hybrid offspring, including transgressive segregation of susceptibility to damage. NMDS analyses revealed significant variation and modest broad-sense heritability in insect community structure among genets. QTL analyses identified 14 genomic regions across 9 linkage groups that correlated with insect association. We used three genomics tools to test for putative mechanisms underlying the QTL. First, shikimate-phenylpropanoid pathway genes co-located to 9 of the 13 QTL tested, consistent with the role of phenolic glycosides as defensive compounds. Second, two insect association QTL corresponded to genomic hotspots for leaf trait QTL as identified in previous studies, indicating that, in addition to biochemical attributes, leaf morphology may influence insect preference. Third, network analyses identified categories of gene models over-represented in QTL for certain damage types, providing direction for future functional studies. These results provide insight into the genetic components involved in insect community structure in a fast-growing forest tree.

Project description:Most food crops are susceptible to necrotrophic bacteria that cause rotting and wilting diseases in fleshy organs and foods. All varieties of cultivated potato (Solanum tuberosum L.) are susceptible to diseases caused by Pectobacterium species, but resistance has been demonstrated in wild potato relatives including S. chacoense. Previous studies demonstrated that resistance is in part mediated by antivirulence activity of phytochemicals in stems and tubers. Little is known about the genetic basis of antivirulence traits, and the potential for inheritance and introgression into cultivated potato is unclear. Here, the metabolites and genetic loci associated with antivirulence traits in S. chacoense were elucidated by screening a sequenced S. tuberosum x S. chacoense recombinant inbred line (RIL) population for antivirulence traits of its metabolite extracts. Metabolite extracts from the RILs exhibited a quantitative distribution for two antivirulence traits that were positively correlated: quorum sensing inhibition and exo-protease inhibition, with some evidence of transgressive segregation, supporting the role of multiple loci and metabolites regulating these resistance-associated systems. Metabolomics was performed on the highly resistant and susceptible RILs that revealed 30 metabolites associated with resistance, including several alkaloids and terpenes. Specifically, several prenylated metabolites were more abundant in resistant RILs. We constructed a high-density linkage map with 795 SNPs mapped to 12 linkage groups, spanning a length of 1,507 cM and a density of 1 marker per 1.89 cM. Genetic mapping of the antivirulence and metabolite data identified five quantitative trait loci (QTLs) related to quorum sensing inhibition that explained 8-28% of the phenotypic variation and two QTLs for protease activity inhibition that explained 14-19% of the phenotypic variation. Several candidate genes including alkaloid, and secondary metabolite biosynthesis that are related to disease resistance were identified within these QTLs. Taken together, these data support that quorum sensing inhibition and exo-protease inhibition assays may serve as breeding targets to improve resistance to nectrotrophic bacterial pathogens in potato and other plants. The identified candidate genes and metabolites can be utilized in marker assisted selection and genomic selection to improve soft- rot and blackleg disease resistance.

Project description:BackgroundHaemonchus contortus, a gastrointestinal nematode parasite of sheep, is mainly controlled by anthelmintics; the occurrence of anthelmintic resistance leads to treatment failures and increases economic burden. Because molecular mechanisms involved in drug resistance can be elucidated by genomic studies, an extreme quantitative trait locus (X-QTL) mapping approach was used to identify co-segregation of the resistance phenotype with genetic markers to detect the genome-wide variants associated with monepantel resistance in H. contortus.MethodsA cross between H. contortus isolates using parental susceptible (Par-S) males and monepantel resistant (Par-R) females resulted in SR progeny, while reciprocal cross resulted in RS progeny. Pools (n = 30,000) of infective larvae (L3) recovered from Par-R, and from SR and RS populations in the F3 generation, collected both before (unselected group) and 7 days after (selected group) selection with monepantel treatment in sheep hosts, were subjected to genome sequencing (Pool-Seq). Pairwise comparisons of allele frequencies between unselected and selected groups were performed for each population by Fisher's exact test (FET) and for both populations combined by a Cochran-Mantel-Haenszel (CMH) test.ResultsMapping rates varied from 80.29 to 81.77% at a 90.4X mean coverage of aligned reads. After correction for multiple testing, significant (P < 0.05) changes in allele frequencies were detected by FET for 6 and 57 single nucleotide polymorphisms (SNPs) in the SR and RS populations, respectively, and by the CMH test for 124 SNPs in both populations. The significant variants located on chromosome 2 generated a selection signal in a genomic region harboring the mptl-1, deg-3 and des-2 genes, previously reported as candidates for monepantel resistance. In addition, three new variants were identified in the mptl-1 gene.ConclusionsThis study expands knowledge on genome-wide molecular events underlying H. contortus resistance to monepantel. The identification of a genome region harboring major genes previously associated with monepantel resistance supports the results of the employed X-QTL approach. In addition, a deletion in exon 11 of the mptl-1 gene should be further investigated as the putative causal mutation leading to monepantel resistance.

Project description:Key messageFine-mapping separated Qfhs.ifa-5A into a major QTL mapping across the centromere and a minor effect QTL positioned at the distal half of 5AS. Both increase Fusarium resistance and anther extrusion. The Fusarium head blight (FHB) resistance QTL Qfhs.ifa-5A resides in the low-recombinogenic pericentromeric region of chromosome 5A making fine-mapping particularly arduous. Qfhs.ifa-5A primarily contributes resistance to fungal entry with the favorable allele descending from the highly Fusarium resistant cultivar Sumai-3. Fine-mapping a near-isogenic recombinant inbred line population partitioned the Qfhs.ifa-5A interval into 12 bins. Near-isogenic lines recombining at the interval were phenotyped for FHB severity, anther retention and plant height. Composite interval mapping separated the initially single QTL into two QTL. The major effect QTL Qfhs.ifa-5Ac mapped across the centromere and the smaller effect QTL Qfhs.ifa-5AS mapped to the distal half of 5AS. Although Qfhs.ifa-5Ac and Qfhs.ifa-5AS intervals were as small as 0.1 and 0.2 cM, their corresponding physical distances were large, comprising 44.1 Mbp and 49.2 Mbp, respectively. Sumai-3 alleles at either QTL improved FHB resistance and increased anther extrusion suggesting a pleiotropic effect of anthers on resistance. This hypothesis was supported by greenhouse experiments using the susceptible cultivar Remus and its resistant near-isogenic line NIL3 carrying the entire Qfhs.ifa-5A segment. By manually removing anthers prior to spray inoculation both, Remus and NIL3 became almost equally resistant in the early phase of the disease development and were significantly less diseased than variants without anther manipulation. At late time points the positive effect of the anther removal became smaller for Remus and disappeared completely for NIL3. Results affirm that absence of anthers enhanced resistance to initial infection but did not protect plants from fungal spreading within spikes.

Dataset Information

QTL mapping of insect resistance components of Solanum galapagense.

Key message

Publications

QTL mapping of insect resistance components of Solanum galapagense.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets