Background:The pathway to form green leaf volatiles is important for plant defense against pathogens and herbivores. Results: Galactolipids with truncated oxoacids are formed as counterparts of green leaf volatiles. Conclusion: Galactolipid-hydroperoxides are substrates for hydroperoxide lyase. Significance: The biosynthetic pathway partly proceeds directly with galactolipids, without the involvement of lipases, to form free fatty acids.