| Title: | Homologs of Caenorhabditis elegans Chemosensory Genes Have Roles in Behavior and Chemotaxis in the Root-Knot Nematode Meloidogyne incognita |
| Author(s): | Shivakumara TN; Dutta TK; Chaudhary S; von Reuss SH; Williamson VM; Rao U; |
| Address: | "1 Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India. 2 Institute of Chemistry, University of Neuchatel, Neuchatel, Avenue de Bellevaux 51, Switzerland. 3 Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A" |
| Journal Title: | Mol Plant Microbe Interact |
| DOI: | 10.1094/MPMI-08-18-0226-R |
| ISSN/ISBN: | 0894-0282 (Print) 0894-0282 (Linking) |
| Abstract: | "Nematode chemosensation is a vital component of their host-seeking behavior. The globally important phytonematode Meloidogyne incognita perceives and responds (via sensory organs such as amphids and phasmids) differentially to various chemical cues emanating from the rhizosphere during the course of host finding. However, compared with the free-living worm Caenorhabditis elegans, the molecular intricacies behind the plant nematode chemotaxis are a yet-unexploited territory. In the present study, four putative chemosensory genes of M. incognita, namely, Mi-odr-1, Mi-odr-3, Mi-tax-2, and Mi-tax-4 were molecularly characterized. Mi-odr-1 mRNA was found to be expressed in the cell bodies of amphidial neurons and phasmids of M. incognita. Mi-odr-1, Mi-odr-3, Mi-tax-2, and Mi-tax-4 transcripts were highly expressed in early life stages of M. incognita, consistent with a role of these genes in host recognition. Functional characterization of Mi-odr-1, Mi-odr-3, Mi-tax-2, and Mi-tax-4 via RNA interference revealed behavioral defects in M. incognita and perturbed attraction to host roots in Pluronic gel medium. Knockdown of Mi-odr-1, Mi-odr-3, Mi-tax-2, and Mi-tax-4 resulted in defective chemotaxis of M. incognita to various volatile compounds (alcohol, ketone, aromatic compound, ester, thiazole, pyrazine), nonvolatiles of plant origin (carbohydrate, phytohormone, organic acid, amino acid, phenolic), and host root exudates in an agar-Pluronic gel-based assay plate. In addition, ascaroside-mediated signaling was impeded by downregulation of chemosensory genes. This new information that behavioral response in M. incognita is modulated by specific olfactory genes can be extended to understand chemotaxis in other nematodes" |
| Keywords: | "Animals Behavior, Animal/physiology Caenorhabditis elegans/genetics *Chemotaxis/genetics RNA Interference *Tylenchoidea/genetics/metabolism nematode-plant interactions;" |
| Notes: | "MedlineShivakumara, Tagginahalli N Dutta, Tushar K Chaudhary, Sonam von Reuss, Stephan H Williamson, Valerie M Rao, Uma eng 2019/02/14 Mol Plant Microbe Interact. 2019 Jul; 32(7):876-887. doi: 10.1094/MPMI-08-18-0226-R. Epub 2019 Jun 10" |
