Integrated transcriptomics and metabolomics decipher differences in the resistance of pedunculate oak to the herbivore Tortrix viridanaL.

Abstract

BackgroundThe interaction between insect pests and their host plants is a never-ending race of evolutionary adaption. Plants have developed an armament against insect herbivore attacks, and attackers continuously learn how to address it. Using a combined transcriptomic and metabolomic approach, we investigated the molecular and biochemical differences between Quercus robur L. trees that resisted (defined as resistant oak type) or were susceptible (defined as susceptible oak type) to infestation by the major oak pest, Tortrix viridana L.ResultsNext generation RNA sequencing revealed hundreds of genes that exhibited constitutive and/or inducible differential expression in the resistant oak compared to the susceptible oak. Distinct differences were found in the transcript levels and the metabolic content with regard to tannins, flavonoids, and terpenoids, which are compounds involved in the defence against insect pests. The results of our transcriptomic and metabolomic analyses are in agreement with those of a previous study in which we showed that female moths prefer susceptible oaks due to their specific profile of herbivore-induced volatiles. These data therefore define two oak genotypes that clearly differ on the transcriptomic and metabolomic levels, as reflected by their specific defensive compound profiles.ConclusionsWe conclude that the resistant oak type seem to prefer a strategy of constitutive defence responses in contrast to more induced defence responses of the susceptible oaks triggered by feeding. These results pave the way for the development of biomarkers for an early determination of potentially green oak leaf roller-resistant genotypes in natural pedunculate oak populations in Europe.

Decoding the oak genome: public release of sequence data, assembly, annotation and publication strategies

“…; Kersten et al . ) were generated. A reference genome for oak will make it possible to extend these findings through a broader exploration of genes of adaptive significance by studying structural and expressional variations in different genetic contexts.…”

“…; Kersten et al . ) and abiotic environments (Dassanayake et al . ) and infer the role of the genes involved in adaptation (Hohenlohe et al .…”

“…This trend is allowing evolutionary biologists to harness the genomic toolbox and to study the rules governing the processes influencing the history, distribution and abundance of organisms (Ekblom & Galindo 2011). Through molecular approaches, they can now easily study the short-term responses of organisms to their biotic (Barakat et al 2009;Kersten et al 2013) and abiotic environments (Dassanayake et al 2009) and infer the role of the genes involved in adaptation (Hohenlohe et al 2010). The oak genome project falls within the scope of this new front line in science, 'Ecological and Evolutionary Genomics', which seeks to understand the genetic mechanisms underlying the past and present responses of organisms to their natural and changing environments.…”

Dual herbivore attack and herbivore density affect metabolic profiles of Brassica nigra leaves

“…Although literature on this topic is limited, both caterpillar and aphid herbivory are known to induce changes in the plant metabolome related to both primary and secondary metabolism. Caterpillar herbivory often leads to large‐scale changes in metabolic profiles (Kersten et al ), although these effects can vary according to the species (Steinbrenner et al ), specialization (generalist versus specialist) (Sutter & Müller ), or larval instar (Widarto et al ). In contrast, aphid infestation triggers metabolome changes on a smaller scale (Kutyniok & Müller ; Sutter & Müller ), which may be a result of the minimal damage caused by the piercing/sucking feeding mode (Will et al ).…”

Plants under dual attack : consequences for plant chemistry and parasitoid behavior

“…Although literature on this topic is limited, both caterpillar and aphid herbivory are known to induce changes in the plant metabolome, with aphid-induced effects of a lower magnitude. Caterpillar herbivory often leads to large scale changes in metabolic profiles (Kersten et al, 2013), though these effects can vary according to the species (Steinbrenner et al, 2011), specialization (generalist versus specialist) (Sutter & Müller, 2011), or larval instar (Widarto et al, 2006). In contrast, aphid infestation triggers metabolome changes on a smaller scale (Sutter & Müller, 2011;Kutyniok & Müller, 2012), which may be a result of the minimal damage caused by the piercing/sucking feeding mode.…”