Green leaf volatiles

Green Leaf Volatiles

Green leaf volatiles (GLVs) are a group of volatile organic compounds that are released by plants when they experience mechanical damage, such as herbivore attack or physical injury. These compounds play a crucial role in plant defense mechanisms and inter-plant communication.

Chemical Composition

GLVs are primarily composed of six-carbon aldehydes, alcohols, and esters. The most common GLVs include hexanal, hexenol, and hexenyl acetate. These compounds are derived from the lipoxygenase pathway, which involves the enzymatic oxidation of fatty acids.

Biosynthesis

Enzymatic pathways involved in the biosynthesis of GLVs.

The biosynthesis of GLVs begins with the action of lipoxygenase on linolenic acid, a fatty acid found in plant membranes. This reaction produces hydroperoxides, which are then cleaved by hydroperoxide lyase to form C6 aldehydes. These aldehydes can be further reduced to alcohols or esterified to form esters.

Ecological Role

GLVs serve multiple ecological functions. They act as signals to attract natural enemies of herbivores, such as predators and parasitoids, thereby providing an indirect defense mechanism for the plant. Additionally, GLVs can signal neighboring plants to activate their own defense responses, a phenomenon known as "priming".

Human Perception and Uses

Humans perceive GLVs as the "green" smell associated with freshly cut grass or crushed leaves. This characteristic aroma is utilized in the flavor and fragrance industries to create products with a fresh, green scent.

Related Pages

• Volatile organic compound
• Plant defense against herbivory
• Lipoxygenase
• Priming (biology)