Why are momilactones always associated with biosynthetic gene clusters in plants?

Abstract

<p>There is an emerging realization that plant genomes contain biosynthetic gene clusters (BGCs) for more specialized metabolism in certain cases (1). However, while horizontal gene transfer seems to drive the assembly of self-sufficient BGCs in microbes, the limitations of strict vertical gene transmission necessitates a distinct driving force for the assembly of BGCs in plants. The evidence for horizontal gene transfer of BGCs in microbes is derived from the appearance of homologous such loci, leading to biosynthesis of the same (or very closely related) natural products, in phylogenetically distinct species. By contrast, there has been much less investigation of such occurrences in plants. This is due to many fewer examples of BGCs, as well as instances of natural products that skip across phylogenetic distances in this kingdom.</p>