Ecology and Evolution of Soil Nematode Chemotaxis

• Published in: Journal of chemical ecology Vol. 38; no. 6; pp. 615 - 628
• Main Authors: Rasmann, Sergio, Ali, Jared Gregory, Helder, Johannes, van der Putten, Wim H.
• Format: Journal Article
• Language: English
• Published: New York Springer-Verlag 01-06-2012; Springer Nature B.V
• Subjects: Agriculture; Animals; Biochemistry; Biological Evolution; Biological Microscopy; Biomedical and Life Sciences; Biota; c-elegans; Carbon dioxide; Chemical ecology; Chemotaxis; Community composition; Ecology; Ecosystem; Entomology; entomopathogenic nematodes; Evolution; globodera-rostochiensis; host search strategies; Host-Parasite Interactions; Life Sciences; meloidogyne-incognita; natural enemies; Nematoda; Nematoda - physiology; Nematodes; phylogenetic-relationships; Phylogeny; Plant ecology; Plant Roots - parasitology; plant-parasitic nematodes; Plants - parasitology; potato cyst nematodes; Rhizosphere; root-feeding caterpillars; Soil - parasitology; Soils; Functional phylogenetic; Soil chemical ecology; Plant-parasitic nematodes; Carbon dioxide; Nematode; Sense organs; Entomopathogenic nematodes; Chemotaxis
• ISSN: 0098-0331; 1573-1561
• DOI: 10.1007/s10886-012-0118-6

Plants influence the behavior of and modify community composition of soil-dwelling organisms through the exudation of organic molecules. Given the chemical complexity of the soil matrix, soil-dwelling organisms have evolved the ability to detect and respond to these cues for successful foraging. A key question is how specific these responses are and how they may evolve. Here, we review and discuss the ecology and evolution of chemotaxis of soil nematodes. Soil nematodes are a group of diverse functional and taxonomic types, which may reveal a variety of responses. We predicted that nematodes of different feeding guilds use host-specific cues for chemotaxis. However, the examination of a comprehensive nematode phylogeny revealed that distantly related nematodes, and nematodes from different feeding guilds, can exploit the same signals for positive orientation. Carbon dioxide (CO
2
), which is ubiquitous in soil and indicates biological activity, is widely used as such a cue. The use of the same signals by a variety of species and species groups suggests that parts of the chemo-sensory machinery have remained highly conserved during the radiation of nematodes. However, besides CO
2
, many other chemical compounds, belonging to different chemical classes, have been shown to induce chemotaxis in nematodes. Plants surrounded by a complex nematode community, including beneficial entomopathogenic nematodes, plant-parasitic nematodes, as well as microbial feeders, are thus under diffuse selection for producing specific molecules in the rhizosphere that maximize their fitness. However, it is largely unknown how selection may operate and how belowground signaling may evolve. Given the paucity of data for certain groups of nematodes, future work is needed to better understand the evolutionary mechanisms of communication between plant roots and soil biota.