Indole Antibiotic Biosynthesis in Edible Plants: From Genomes to Bioactive Molecules    
A. KLEIN (1), E. Sattely (2) (1) Stanford University, U.S.A.; (2) Stanford University, U.S.A.

The construction of antimicrobial chemicals is a central feature of the plant defense response to stress. Cruciferous vegetables (Brassicaceae family) produce a bouquet of sulfur-containing molecules that restrict fungal pathogens and also possess drug-like activities in humans. Knowledge of the enzymes that assemble these natural compounds — termed the biosynthetic pathway — is crucial to robustly test their biological functions, such as in plant–microbe interactions. Furthermore, elucidating a complete biosynthetic pathway would open the door to targeted breeding or metabolic engineering of these pathways for plant and human health. Here I describe three studies that discover and characterize enzymes involved in plant specialized metabolism. These investigations employ a combination of mass spectrometry-based metabolite profiling, gene expression analysis, and enzyme biochemistry. The three studies include: (i) uncovering a branch point for phytoalexin biosynthesis in Arabidopsis thaliana; (ii) identifying the first enzymes in the brassinin pathway from Brassica rapa; and (iii) progressing to characterize the entire pathway of Brassica phytoalexin biosynthesis, and examining the chemical diversity across >20 genome-sequenced species in Brassicaceae and sister families. The biochemical and genetic basis of phytoalexin biosynthesis elucidated here provides insights into the evolution of the complex chemical communication among plants and their associated microbiota.    

Abstract Number: C4-3, P3-85
Session Type: Concurrent