Chemical convergence between plants and insects: biosynthetic origins and functions of common secondary metabolites

First author: Franziska Beran; Affiliations: Max Planck Institute for Chemical Ecology (马克斯-普朗克化学生态学研究所): Jena, Germany

Corresponding author: Dorothea Tholl

Despite the phylogenetic distance between plants and insects, these two groups of organisms produce some secondary metabolites in common. Identical structures belonging to chemical classes such as the simple monoterpenes and sesquiterpenes, iridoid monoterpenes, cyanogenic glycosides, benzoic acid derivatives, benzoquinones and naphthoquinones are sometimes found in both plants and insects. In addition, very similar glucohydrolases involved in activating two component defenses, such as glucosinolates and cyanogenic glycosides, occur in both plants and insects. While this trend was first noted many years ago, researchers have long struggled to find convincing explanations for such co‐occurrence. In some cases, identical compounds may be produced by plants to interfere with their function in insects. But, in other cases, plant and insect compounds may simply have parallel functions, probably in defense or attraction, and their co‐occurrence is a coincidence. The biosynthetic origin of such co‐occurring metabolites may be very different in insects as compared to plants. Plants and insects may have different pathways to the same metabolite, or similar sequences of intermediates, but different enzymes. Further knowledge of the ecological roles and biosynthetic pathways of secondary metabolites may shed more light on why plants and insects produce identical substances.

植物与昆虫之间除了在演化上的关系外，这两者某些物种还会产生一些共同的次生代谢物。在植物和昆虫中经常会鉴定到一些属于同一类化学结构的物质，比如单萜类和倍半萜类、环烯醚萜类、氰苷类、苯甲酸衍生物以及苯醌类和萘醌类化合物。另外，参与双组分防御激活的葡聚糖水解酶硫代葡萄糖苷和氰甙在植物和昆虫中均存在。当第一次有人注意到这种情况的时候，研究人员们就一直致力于寻求这种共存状态发生的合理解释。某些情况下，植物会产生与昆虫中结构一样的化合物以干扰昆虫中这类化合物的功能。但在其它的情况下，植物和昆虫化合物可能会具有类似的功能，可能作用于防御或性吸引，而这种类似化合物的共存可能只是一种巧合。昆虫中这类化合物的合成可能与植物中的完全不一样。植物和昆虫可能会有不同的通路产生同一种化合物或类似的中间产物，但作用的酶完全不同。进一步的对这些次生代谢物的生态作用及生物合成通路的研究将有助于理解植物为何和昆虫产生一致的物质。

doi: https://doi.org/10.1111/nph.15718

Journal: New Phytologist

First Published: February 01, 2019