Defensive changes in maize leaves induced by feeding of Mediterranean corn borer larvae

Abstract

BackgroundPlants can respond to insect attack via defense mechanisms that reduce insect performance. In this study, we examined the effects of several treatments applied to two maize genotypes (one resistant, one susceptible) on the subsequent growth and survival of Sesamia nonagrioides Lef. (Mediterranean corn borer, MCB) larvae. The treatments were infestation with MCB larvae, application of MCB regurgitant upon wounding, wounding alone, or exposure to methyl jasmonate, and they were applied at the V6–V8 stage of maize development. We also monitored changes in the concentrations of compounds known to be involved in constitutive resistance, such as cell wall-bound hydroxycinnamates and benzoxazinoids.ResultsIn both maize genotypes, the leaves of plants pre-infested with MCB larvae were less suitable for larval development than those from untreated plants. Application of MCB regurgitant upon wounding, and wounding itself, resulted in leaf tissues becoming less suitable for larval growth than those of pre-infested plants, suggesting that there could be herbivore-associated effector molecules that suppress some wounding responses. A single application of MCB regurgitant did not seem to mimic feeding by MCB larvae, although the results suggested that regurgitant deposited during feeding may have enhanced ferulates and diferulates synthesis in infested vs. control plants. Jasmonic acid may play a role in mediating the maize response to MCB attack, but it did not trigger hydroxycinnamate accumulation in the leaves to a level comparable to that induced by larval leaf feeding. The EP39 maize genotype showed an increase in leaf cell wall strength by increasing hemicellulose cross-linking in response to MCB attack, while induced defenses in the EP42 plants appeared to reflect a broader array of resistance mechanisms.ConclusionsThe results indicated that leaf feeding by MCB larvae can increase leaf antibiosis against MCB in two maize genotypes with contrasting levels of resistance against this borer. Also, the larval regurgitant played a positive role in eliciting a defense response. We determined the effects of the plant response on larval growth, and detected defense compounds related to borer resistance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-017-0991-9) contains supplementary material, which is available to authorized users.

Diverse lignocellulosic feedstocks can achieve high field‐scale ethanol yields while providing flexibility for the biorefinery and landscape‐level environmental benefits

“…It is unclear as to the reason for the elevated hydroxycinnamate levels in the 2014 corn stover compared to the other years investigated for the same hybrid (2012 and 2013). Maize pest herbivory has been shown to cause an increase in hydroxycinnamate content (Santiago et al, 2017), and it may be that pest infestation of the maize grown in 2014 was higher compared with other years, although we have no data on pest infestation to support or disprove this hypothesis. Another possibility is that environmental conditions, such as temperature and precipitation, affected the quality of the corn biomass during that growing season.…”

Maize Combined Insect Resistance Genomic Regions and Their Co-localization With Cell Wall Constituents Revealed by Tissue-Specific QTL Meta-Analyses

“…Cell wall components (CWC), especially fiber and hydroxycinnamates provide maize resistance to feeding by several stem borers (Cardinal and Lee, 2005 ; Krakowsky et al, 2007 ; Santiago et al, 2016 ). Fiber components such as acid detergent fiber (ADF), neutral detergent fiber (NDF), and lignin, and hydroxycinnamates such a p -coumaric acid ( p -CA), ferulic acid (FA), and diferulic acid (DiFA), which are byproducts of the phenylpropanoids pathway, are involved in maize resistance to ECB, SCB, SWCB, and MCB both in leaves and stems (Santiago et al, 2013 , 2017 ). Besides, the hydroxycinnamates and several other cell wall bound constituents are also associated with maize kernels resistance to MW (García-lara et al, 2010 ; Castro-Álvarez et al, 2015 ).…”

Genetic Diversity and Responses of Some Selected Yellow Maize Genotypes to Stem Borer (Sesamia calamistis Hampson) Infestation

“…Maize (Zea mays L) is an important cereal crop in Africa serving as source of food and industrial raw material for industries such as brewery, confectionery, livestock and flour feed mills [1]. Despite its importance, maize grain yield is severely constrained by biotic stress, especially stem-borer (S. calamistis) infestation.The activities of the stem-borers' larvae on maize plants result in leaf feeding and stem tunnelling, which in turn leads to reduced translocation of nutrients and assimilates to appropriate sinks, death of young plants (dead heart), lodging of older plants and direct damage to maize ears [2,3].…”