Volatile compounds from plants. Origin, emission, effects, analysis and agro applications

Abstract

Plants produce and emit large amounts of volatile organic compounds. The smell produced by plants has always been recognized for its commercial and aesthetic value and it is emitted not only from flowers and fruits, but also from vegetative tissues. Since approximately two decades, the influence of these scents in a vast array of interactions has been established carrying out physiological, ecological and more recently atmospheric functions. Generally these mixtures consist of terpenes, fatty acid derivatives and aromatic compounds. One of the major volatile's role is their involvement as signals to other organisms, and even for the same plant. Furthermore, they can be exported to modify the environment of the releaser species and influence the behavior of neighbors and enemies. Chemical volatiles have so many functions: in plant reproduction, attracting pollinators or seed dispersers

in chemical defense, repelling insects, avoiding bacterial or fungi phytopathogen colonization, attracting natural enemies of herbivores

or using them like intra and inter specific messengers. The progress on analytical techniques, molecular biology and biochemistry, have allowed the elucidation of biosynthetic pathways, enzymes and genes involved in plant volatiles production and emission, helping to understand, partially, the reason why this kind of compounds perform an active role in organisms and environmental relationships. This review offers a general vision about properties of plant volatiles, including the function that these compounds accomplish in several relationships at different trophic levels.