title: Ethylene response pathway modulates attractiveness of plant roots to soybean cyst nematode Heterodera glycines.
abstract: Plant parasitic nematodes respond to root exudates to locate their host roots. In our studies second stage juveniles of Heterodera glycines, the soybean cyst nematode (SCN), quickly migrated to soybean roots in Pluronic F-127 gel. Roots of soybean and non-host Arabidopsis treated with the ethylene (ET)-synthesis inhibitor aminoethoxyvinylglycine (AVG) were more attractive to SCN than untreated roots, and significantly more nematodes penetrated into roots. Moreover, Arabidopsis ET insensitive mutants (ein2, ein2-1, ein2-5, ein3-1, ein5-1, and ein6) were more attractive than wild-type plants. Conversely, the constitutive triple-response mutant ctr1-1, was less attractive to SCN. While ET receptor gain-of-function mutant ein4-1 attracted more SCN than the wild-type, there were no significant differences in attractiveness between another gain-of-function ET receptor mutant, etr1-3, or the loss-of-function mutants etr1-7 and ers1-3 and the wild type. Expression of the reporter construct EBS: β-glucuronidase (GUS) was detected in Arabidopsis root tips as early as 6 h post infection, indicating that ET signaling was activated in Arabidopsis early by SCN infection. These results suggest that an active ET signaling pathway reduces root attractiveness to SCN in a way similar to that reported for root-knot nematodes, but opposite to that suggested for the sugar beet cyst nematode Heterodera schachtii.
authors.affiliation: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081 China.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081 China.
authors.forename: Jia
authors.initials: J
authors.lastname: You
authors.affiliation: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081 China.
authors.forename: Chunjie
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Plant Pathology, University of California, Davis, CA 95616 USA.
authors.forename: Valerie M
authors.initials: VM
authors.lastname: Williamson
authors.affiliation: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081 China.
authors.forename: Congli
authors.initials: C
authors.lastname: Wang
mesh_terms: D000818:Animals; D005030:Ethylenes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D009943:Organophosphorus Compounds / Q000494:pharmacology; D010935:Plant Diseases / Q000469:parasitology*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000469:parasitology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013025:Glycine max / Q000187:drug effects / Q000235:genetics / Q000469:parasitology*; D014431:Tylenchoidea / Q000187:drug effects / Q000502:physiology*
chemical_list: D005030:Ethylenes; D009943:Organophosphorus Compounds; D011956:Receptors, Cell Surface; C036216:ethylene; C088137:aminoethoxyvinylglycine; D005998:Glycine; C005073:ethephon