Metabolic profiling of Persea americana cv. Hass branch volatiles reveals seasonal chemical changes associated to the avocado branch borer, Copturus aguacatae

Abstract Plants produce a plethora of variable metabolites that could be involved in constitutive and induced defense against herbivorous insects. Recently, metabolomics have showed to be a complementary approach in chemical ecology to screen dozens of plant metabolites, and identify those related with plant resistance or susceptibility to herbivorous insects. We compared GC–MS metabolic profiles of cambial tissue from Persea americana cv. Hass trees infested and non-infested by the avocado branch borer (ABB), Copturus aguacatae , and between undamaged and ABB damaged branches from the same tree. Using several multivariate techniques we discriminated between several overlaid dimensions of branches phytochemical variation (intraclonal, seasonal and induced response). Specifically, we found a set of sixteen highly correlated terpenoids, showing increasing proportions in borer trees as response to ABB larvae. In addition, low proportions of isoobtusilactone A and α-humulene were found in non-bored trees. The implications of dimensions of avocado phytochemical variation, and diversity as defensive traits in the interaction with Copturus aguacatae are discussed.