Genetic Basis of Maize Resistance to Multiple Insect Pests: Integrated Genome-Wide Comparative Mapping and Candidate Gene Prioritization
Open Access
- 24 June 2020
- Vol. 11 (6), 689
- https://doi.org/10.3390/genes11060689
Abstract
Several species of herbivores feed on maize in field and storage setups, making the development of multiple insect resistance a critical breeding target. In this study, an association mapping panel of 341 tropical maize lines was evaluated in three field environments for resistance to fall armyworm (FAW), whilst bulked grains were subjected to a maize weevil (MW) bioassay and genotyped with Diversity Array Technology’s single nucleotide polymorphisms (SNPs) markers. A multi-locus genome-wide association study (GWAS) revealed 62 quantitative trait nucleotides (QTNs) associated with FAW and MW resistance traits on all 10 maize chromosomes, of which, 47 and 31 were discovered at stringent Bonferroni genome-wide significance levels of 0.05 and 0.01, respectively, and located within or close to multiple insect resistance genomic regions (MIRGRs) concerning FAW, SB, and MW. Sixteen QTNs influenced multiple traits, of which, six were associated with resistance to both FAW and MW, suggesting a pleiotropic genetic control. Functional prioritization of candidate genes (CGs) located within 10–30 kb of the QTNs revealed 64 putative GWAS-based CGs (GbCGs) showing evidence of involvement in plant defense mechanisms. Only one GbCG was associated with each of the five of the six combined resistance QTNs, thus reinforcing the pleiotropy hypothesis. In addition, through in silico co-functional network inferences, an additional 107 network-based CGs (NbCGs), biologically connected to the 64 GbCGs, and differentially expressed under biotic or abiotic stress, were revealed within MIRGRs. The provided multiple insect resistance physical map should contribute to the development of combined insect resistance in maize.Other Versions
Funding Information
- Carnegie Corporation of New York (RUFORUM: RU/2016/Intra-ACP/RG/001)
This publication has 115 references indexed in Scilit:
- Comprehensive genotyping of the USA national maize inbred seed bankGenome Biology, 2013
- Impact of Cell Wall Composition on Maize Resistance to Pests and DiseasesInternational Journal of Molecular Sciences, 2013
- The advantages and limitations of trait analysis with GWAS: a reviewPlant Methods, 2013
- Comparative Sequence Analysis of the Ghd7 Orthologous Regions Revealed Movement of Ghd7 in the Grass GenomesPLOS ONE, 2012
- Comparative Analysis of Syntenic Genes in Grass Genomes Reveals Accelerated Rates of Gene Structure and Coding Sequence Evolution in Polyploid WheatPlant Physiology, 2012
- Mechanisms of plant defense against insect herbivoresPlant Signaling & Behavior, 2012
- Comparative SNP and Haplotype Analysis Reveals a Higher Genetic Diversity and Rapider LD Decay in Tropical than Temperate Germplasm in MaizePLOS ONE, 2011
- RefGenes: identification of reliable and condition specific reference genes for RT-qPCR data normalizationBMC Genomics, 2011
- A unified mixed-model method for association mapping that accounts for multiple levels of relatednessNature Genetics, 2005
- Quantitative Trait Loci Conferring Resistance to Fall Armyworm and Southwestern Corn Borer Leaf Feeding DamageCrop Science, 2005