Proteomics of opium poppy latex

Opium poppy accumulates copious amounts of several benzylisoquinoline alkaloids including morphine, noscapine, and papaverine, in the specialized cytoplasm of laticifers. The contiguous latex includes an abundance of related proteins belonging to the pathogenesis-related (PR)10 family known collectively as major latex proteins (MLPs) and representing at least 35% of the total cellular protein content. We show that the major latex proteins are a family of alkaloid-binding proteins.