Profiling of volatile organic compounds released from individual intact juvenile and mature citrus leaves

Plants release volatiles to communicate with each other and to attract or repel insects. The methods used to collect volatiles are varied. Here, we describe a simple solvent-less, solid phase microextraction-based method to collect the volatiles released from intact citrus leaves. We were able to collect up to 39 volatiles from both juvenile and mature leaves. Our results indicated that juvenile leaves produced both monoterpenes and sesquiterpenes, and while mature leaves continued to produce a variety of monoterpenes, their release of sesquiterpenes decreased dramatically. The finding that juvenile leaves emitted higher levels of sesquiterpenes while mature leaves released mostly monoterpenes suggests that younger leaves of plants may be involved in a more complex chemical communication system. (C) 2016 Elsevier GmbH. All rights reserved.