The beet cyst nematode Heterodera schachtii causes major yield losses in sugar beet. Understanding the interaction between H. schachtii and its host plant is important for developing a sustainable management system. Nematode effectors play a crucial role in initializing and sustaining successful parasitism. In our study, we identified a gene (Hs-Tyr) encoding a tyrosinase functional domain (PF00264). We describe Hs-Tyr as a novel nematode effector. Hs-Tyr is localized in the nematode esophageal gland. Up-regulation of its expression coincided with the parasitic developmental stages of the nematode. Silencing Hs-Tyr by RNA interference made the treated nematodes less virulent. When RNAi-treated nematodes succeeded in infecting the plant, developing females and their associated syncytial nurse cells were significantly smaller than in control plants. Ectopically expressing the Hs-Tyr effector in Arabidopsis increased plant susceptibility to H. schachtii, but not to the root-knot nematode Meloidogyne incognita. Interestingly, Hs-Tyr in the plant promoted plant growth and changed the root architecture. Additionally, the expression of Hs-Tyr in Arabidopsis caused changes in the homeostasis of several plant hormones especially auxin and the ethylene precursor aminocyclopropane-carboxylic acid.

• MeSH
• Arabidopsis metabolismus   parazitologie   MeSH
• ezofágus metabolismus   MeSH
• hlístice metabolismus   patogenita   MeSH
• interakce hostitele a parazita * MeSH
• proteiny červů genetika   metabolismus   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• tyrosinasa genetika   metabolismus   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• proteiny červů MeSH
• regulátory růstu rostlin MeSH
• tyrosinasa MeSH

Above- and belowground plant parts are simultaneously attacked by different pests and pathogens. The host mediates these interactions and physiologically reacts, e.g. with local and systemic alterations of endogenous hormone levels coupled with coordinated transcriptional changes. This in turn affects attractiveness and susceptibility of the plant to subsequent attackers. Here, the model plant Arabidopsis thaliana is used to study stress hormone-based systemic responses triggered by simultaneous root parasitism by the cyst nematode Heterodera schachtii and shoot herbivory by the thrips Frankliniella occidentalis and the spider mite Tetranychus urticae. First, HPLC/MS and quantitative reverse transcriptase PCR are used to show that nematode parasitism strongly affects stress hormone levels and expression of hormone marker genes in shoots. Previous nematode infection is then demonstrated to affect the behavioural and life history performance of both arthropods. While thrips explicitly avoid nematode-infected plants, spider mites prefer them. In addition, the life history performance of T. urticae is significantly enhanced by nematode infection. Finally, systemic changes triggered by shoot-feeding F. occidentalis but not T. urticae are shown to make the roots more attractive for H. schachtii. This work emphasises the importance of above- and belowground signalling and contributes to a better understanding of plant systemic defence mechanisms against plant-parasitic nematodes.

• Klíčová slova
• Aboveground–belowground interactions, Frankliniella occidentalis, Heterodera schachtii, Tetranychus urticae., herbivores, phytohormones, plant-parasitic nematodes, systemic responses,
• MeSH
• Arabidopsis imunologie   parazitologie   MeSH
• býložravci * MeSH
• kořeny rostlin imunologie   parazitologie   MeSH
• mezibuněčná komunikace MeSH
• regulátory růstu rostlin fyziologie   MeSH
• rostlinné buňky metabolismus   MeSH
• Tetranychidae fyziologie   MeSH
• Thysanoptera fyziologie   MeSH
• Tylenchoidea fyziologie   MeSH
• výhonky rostlin imunologie   parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• regulátory růstu rostlin MeSH