The emerging role of biosynthetic gene clusters in plant defense and plant interactions
Guy Polturak, Anne Osbourn
Abstract
The plant kingdom produces a diverse array of chemicals, collectively making an estimated 105 to 106 different metabolites [1,2]. These compounds are either known or likely to have important ecological functions, for example, in providing protection against herbivores, pests, and pathogens; in allelopathy (competition with neighboring plants); and in shaping the plant microbiome. In some cases, they have also been shown to function as regulators of plant growth and defense as well as primary metabolites sensu lato [3]. Plant natural products are formed by a series of enzyme-mediated chemical reactions that together constitute biosynthetic pathways. While it is well known that the genes for some well-characterized plant natural product pathways are dispersed throughout the genome, the last 2 decades have revealed a growing number of examples in which the genes for specific biosynthetic pathways are co-localized in plant genomes in biosynthetic gene clusters (BGCs). Several comprehensive reviews covering the nature and general features of plant BGCs have been published previously [4–8]. However, there has not as yet been a focused review of the roles of these clusters in the context of plant defense and plant interactions. Here, we review this topic, highlight major recent advances in the field, and discuss potential implications for crop improvement.