| Title: | Parasitic nematode Meloidogyne incognita interactions with different Capsicum annum cultivars reveal the chemical constituents modulating root herbivory |
| Author(s): | Kihika R; Murungi LK; Coyne D; Ng'ang'a M; Hassanali A; Teal PEA; Torto B; |
| Address: | "Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya. Kenyatta University, P.O. Box 43844- 00100, Nairobi, Kenya. Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya. International Institute of Tropical Agriculture (IITA), P.O. Box 30772-00100, Nairobi, Kenya. USDA/ARS-CMAVE, 1600/1700 SW23rd Dr., Gainesville, FL, 32608, USA. Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya. btorto@icipe.org" |
| DOI: | 10.1038/s41598-017-02379-8 |
| ISSN/ISBN: | 2045-2322 (Electronic) 2045-2322 (Linking) |
| Abstract: | "Plant volatile signatures are often used as cues by herbivores to locate their preferred hosts. Here, we report on the volatile organic compounds used by the subterranean root-knot nematode (RKN) Meloidogyne incognita for host location. We compared responses of infective second stage juveniles (J2s) to root volatiles of three cultivars and one accession of the solanaceous plant, Capsicum annum against moist sand in dual choice assays. J2s were more attracted to the three cultivars than to the accession, relative to controls. GC/MS analysis of the volatiles identified common constituents in each plant, five of which were identified as alpha-pinene, limonene, 2-methoxy-3-(1-methylpropyl)-pyrazine, methyl salicylate and tridecane. We additionally identified thymol as being specific to the accession. In dose-response assays, a blend of the five components elicited positive chemotaxis (71-88%), whereas individual components elicited varying responses; Methyl salicylate (MeSA) elicited the highest positive chemotaxis (70-80%), alpha-pinene, limonene and tridecane were intermediate (54-60%), and 2-methoxy-3-(1-methylpropyl)-pyrazine the lowest (49-55%). In contrast, thymol alone or thymol combined with either the preferred natural plant root volatiles or the five-component synthetic blend induced negative chemotaxis. Our results provide insights into RKN-host plant interactions, creating new opportunities for plant breeding programmes towards management of RKNs" |
| Keywords: | Animals Capsicum/*chemistry/*parasitology Gas Chromatography-Mass Spectrometry *Herbivory Phytochemicals/*chemistry Plant Diseases/parasitology Plant Roots/*chemistry/*parasitology Tylenchoidea/*physiology Volatile Organic Compounds/analysis/chemistry; |
| Notes: | "MedlineKihika, Ruth Murungi, Lucy K Coyne, Danny Ng'ang'a, Margaret Hassanali, Ahmed Teal, Peter E A Torto, Baldwyn eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. England 2017/06/08 Sci Rep. 2017 Jun 6; 7(1):2903. doi: 10.1038/s41598-017-02379-8" |
