Transcriptome analysis of contrasting resistance to herbivory by Empoasca fabae in two shrub willow species and their hybrid progeny

PLoS One. 2020 Jul 29;15(7):e0236586. doi: 10.1371/journal.pone.0236586. eCollection 2020.

Abstract

Short rotation woody biomass cultivars developed from fast-growing shrub species of willow (Salix spp.) have superior properties as perennial energy crops for the Northeast and Midwest US. However, the insect pest potato leafhopper (PLH) Empoasca fabae (Harris) can cause serious damage and reduce yield of susceptible genotypes. Currently, the willow cultivars in use display varying levels of susceptibility under PLH infestation. However, genes and markers for resistance to PLH are not yet available for marker-assisted selection in breeding. In this study, transcriptome differences between a resistant genotype 94006 (S. purpurea) and a susceptible cultivar 'Jorr' (S. viminalis), and their hybrid progeny were determined. Over 600 million RNA-Seq reads were generated and mapped to the Salix purpurea reference transcriptome. Gene expression analyses revealed the unique defense mechanism in resistant genotype 94006 that involves PLH-induced secondary cell wall modification. In the susceptible genotypes, genes involved in programed cell death were highly expressed, explaining the necrosis symptoms after PLH feeding. Overall, the discovery of resistance genes and defense mechanisms provides new resources for shrub willow breeding and research in the future.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Cell Wall / chemistry
  • Cell Wall / metabolism
  • Crops, Agricultural
  • Gene Expression Profiling
  • Gene Regulatory Networks / genetics
  • Genotype
  • Hemiptera / physiology
  • Herbivory
  • Host-Parasite Interactions / genetics
  • Phenotype
  • Principal Component Analysis
  • RNA, Plant / chemistry
  • RNA, Plant / metabolism
  • Salix / genetics*
  • Salix / parasitology
  • Transcriptome*

Substances

  • RNA, Plant

Grants and funding

Primary support for this research was provided to LBS and JEC as grant No. 2012-68005-19703 from the USDA Agriculture and Food Research Initiative of the National Institute of Food and Agriculture (https://nifa.usda.gov/grants). Additional support was provided to JEC from through the USDA National Institute of Food and Agriculture Federal Appropriations (https://nifa.usda.gov/nifas-discretionary-and-mandatoryfunding) under Project PEN04532 and Accession number 1000326. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.