title: Transcriptional changes of the root-knot nematode Meloidogyne incognita in response to Arabidopsis thaliana root signals.
abstract: Root-knot nematodes are obligate parasites that invade roots and induce the formation of specialized feeding structures. Although physiological and molecular changes inside the root leading to feeding site formation have been studied, very little is known about the molecular events preceding root penetration by nematodes. In order to investigate the influence of root exudates on nematode gene expression before plant invasion and to identify new genes potentially involved in parasitism, sterile root exudates from the model plant Arabidopsis thaliana were produced and used to treat Meloidogyne incognita pre-parasitic second-stage juveniles. After confirming the activity of A. thaliana root exudates (ARE) on M. incognita stylet thrusting, six new candidate genes identified by cDNA-AFLP were confirmed by qRT-PCR as being differentially expressed after incubation for one hour with ARE. Using an in vitro inoculation method that focuses on the events preceding the root penetration, we show that five of these genes are differentially expressed within hours of nematode exposure to A. thaliana roots. We also show that these genes are up-regulated post nematode penetration during migration and feeding site initiation. This study demonstrates that preceding root invasion plant-parasitic nematodes are able to perceive root signals and to respond by changing their behaviour and gene expression.
authors.affiliation: Rothamsted Research, Harpenden, Herts, United Kingdom. teillet@wisc.edu
authors.forename: Alice
authors.initials: A
authors.lastname: Teillet
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Dybal
authors.forename: Brian R
authors.initials: BR
authors.lastname: Kerry
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Miller
authors.forename: Rosane H C
authors.initials: RH
authors.lastname: Curtis
authors.forename: Peter
authors.initials: P
authors.lastname: Hedden
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D000818:Animals; D017360:Arabidopsis / Q000187:drug effects / Q000469:parasitology*; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D017238:Genes, Helminth; D006790:Host-Parasite Interactions / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics / Q000469:parasitology*; D053147:Plant Exudates / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects / Q000469:parasitology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic / Q000187:drug effects*; D014431:Tylenchoidea / Q000187:drug effects / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D053147:Plant Exudates; D012333:RNA, Messenger