Volatile Exchange Between Undamaged Plants - A New Mechanism Affecting Insect Orientation in Intercropping

PLoS One. 2013 Jul 29;8(7):e69431. doi: 10.1371/journal.pone.0069431. Print 2013.

Abstract

Changes in plant volatile emission can be induced by exposure to volatiles from neighbouring insect-attacked plants. However, plants are also exposed to volatiles from unattacked neighbours, and the consequences of this have not been explored. We investigated whether volatile exchange between undamaged plants affects volatile emission and plant-insect interaction. Consistently greater quantities of two terpenoids were found in the headspace of potato previously exposed to volatiles from undamaged onion plants identified by mass spectrometry. Using live plants and synthetic blends mimicking exposed and unexposed potato, we tested the olfactory response of winged aphids, Myzus persicae. The altered potato volatile profile deterred aphids in laboratory experiments. Further, we show that growing potato together with onion in the field reduces the abundance of winged, host-seeking aphids. Our study broadens the ecological significance of the phenomenon; volatiles carry not only information on whether or not neighbouring plants are under attack, but also information on the emitter plants themselves. In this way responding plants could obtain information on whether the neighbouring plant is a competitive threat and can accordingly adjust their growth towards it. We interpret this as a response in the process of adaptation towards neighbouring plants. Furthermore, these physiological changes in the responding plants have significant ecological impact, as behaviour of aphids was affected. Since herbivore host plants are potentially under constant exposure to these volatiles, our study has major implications for the understanding of how mechanisms within plant communities affect insects. This knowledge could be used to improve plant protection and increase scientific understanding of communication between plants and its impact on other organisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aphids / drug effects
  • Aphids / physiology*
  • Crops, Agricultural / parasitology*
  • Flight, Animal / physiology
  • Odorants
  • Onions / parasitology
  • Orientation / drug effects*
  • Smell / drug effects
  • Smell / physiology
  • Solanum tuberosum / parasitology
  • Terpenes / pharmacology
  • Volatile Organic Compounds / pharmacology*

Substances

  • Terpenes
  • Volatile Organic Compounds

Grant support

The study was financially supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Project No. III 46008– Development of integrated management of harmful organisms in plant production in order to overcome resistance and to improve food quality and safety) and by the Swedish Foundation for Strategic Environmental Research (MISTRA) through the PlantComMistra programme. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.