Towards global understanding of plant defence against aphids--timing and dynamics of early Arabidopsis defence responses to cabbage aphid (Brevicoryne brassicae) attack.
Insect feeding on plants causes a complex series of coordinated defence responses. Little is known, however, about the time-dependent aspect of induced changes. Here we present a time series-based investigation of Arabidopsis thaliana Ler subjected to attack by a specialist pest of Brassicaceae species, Brevicoryne brassicae. Transcriptome and metabolome changes were studied at 6, 12, 24 and 48 h after infestation to monitor the progress of early induced responses. The use of full-genome oligonucleotide microarrays revealed the initiation of extensive gene expression changes already during the first 6 h of infestation. Data indicated the involvement of reactive oxygen species (ROS) and calcium in early signalling, and salicylic acid (SA) and jasmonic acid (JA) in the regulation of defence responses. Transcripts related to senescence, biosynthesis of anti-insect proteins, indolyl glucosinolates (GS) and camalexin, as well as several uncharacterized to date WRKY transcription factors, were induced. Follow-up studies of defence-involved secondary metabolites revealed depositions of callose at the insects' feeding sites, a decrease in the total level of aliphatic GS, particularly 3-hydroxypropyl glucosinolate, and accumulation of 4-methoxyindol-3-ylmethyl glucosinolate 48 h after the attack. The novel role of camalexin, induced as a part of defence against aphids, was verified in fitness experiments. Fecundity of B. brassicae was reduced on camalexin-accumulating wild-type (WT) plants as compared with camalexin-deficient pad3-1 mutants. Based on experimental data, a model of plant-aphid interactions at the early phase of infestation was proposed.
Kuśnierczyk
Anna
A
Department of Biology, The Norwegian University of Science and Technology, Realfagbygget, 7491 Trondheim, Norway.
Winge
Per
P
Jørstad
Tommy S
TS
Troczyńska
Joanna
J
Rossiter
John T
JT
Bones
Atle M
AM
D000818:Animals; D001042:Aphids / Q000187:drug effects / Q000502:physiology*; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000276:immunology* / Q000469:parasitology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001937:Brassica / Q000469:parasitology*; D020013:Calcium Signaling / Q000187:drug effects; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism / Q000469:parasitology; D003517:Cyclopentanes / Q000494:pharmacology; D005030:Ethylenes / Q000494:pharmacology; D005298:Fertility / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005961:Glucosinolates / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007211:Indoles / Q000378:metabolism; D008954:Models, Biological; D018384:Oxidative Stress / Q000187:drug effects; D054883:Oxylipins / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism / Q000469:parasitology; D020156:Salicylic Acid / Q000494:pharmacology; D013844:Thiazoles / Q000378:metabolism; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D000094162:Phytoalexins
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D005030:Ethylenes; D005961:Glucosinolates; D006861:Hydrogen Peroxide; D007211:Indoles; D054883:Oxylipins; D020156:Salicylic Acid; D013844:Thiazoles; D014157:Transcription Factors; C102405:camalexin; D000094162:Phytoalexins; C011006:jasmonic acid