Plasmodiophora brassicae, a soil-borne biotroph, establishes galls as strong physiological sinks on Brassicaceae plants including Brassica napus and Arabidopsis thaliana. We compare transcriptional profiles of phloem dissected from leaf petioles and hypocotyls of healthy and infected B. napus plants. Our results highlight how pathogenesis accompanies phloem-mediated defence responses whilst exerting a strong influence on carbon-nitrogen (C-N) economy. We observe transcriptional changes indicating decreased aliphatic glucosinolate biosynthesis, fluctuating jasmonic acid responses, altered amino acid (AA) and nitrate transport, carbohydrate metabolism and modified cytokinin responses. Changes observed in phloem-dissected from upper versus lower plant organs point to phloem as a conduit in mediating C-N repartitioning, nutrition-related signalling and cytokinin dynamics over long distances during clubroot disease. To assess changes in physiology, we measured AAs, sugars and cytokinins, in phloem exudates from B. napus plants. Despite the decrease in most AA and sucrose levels, isopentyl-type cytokinins increased within infected plants. Furthermore, we employed Arabidopsis for visualising promoter activities of B. napus AA and N transporter orthologues and tested the impact of disrupted cytokinin transport during P. brassicae-induced gall formation using Atabcg14 mutants. Our physiological and microscopy studies show that the host developmental reaction to P. brassicae relies on cytokinin and is accompanied by intense nitrogen and carbon repartitioning. Overall, our work highlights the systemic aspects of host responses that should be taken into account when studying clubroot disease.

• Klíčová slova
• Brassica napus, Plasmodiophora brassicae, clubroot, laser dissection transcriptomics, oilseed rape, phloem,
• MeSH
• aminokyseliny metabolismus   MeSH
• Arabidopsis * genetika   fyziologie   MeSH
• Brassica napus * genetika   metabolismus   fyziologie   parazitologie   MeSH
• cyklopentany metabolismus   MeSH
• cytokininy metabolismus   MeSH
• dusík metabolismus   MeSH
• floém * metabolismus   genetika   MeSH
• glukosinoláty metabolismus   MeSH
• listy rostlin genetika   metabolismus   MeSH
• nemoci rostlin * parazitologie   genetika   MeSH
• oxylipiny metabolismus   MeSH
• Plasmodiophorida * fyziologie   MeSH
• regulace genové exprese u rostlin * MeSH
• transkriptom MeSH
• uhlík metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminokyseliny MeSH
• cyklopentany MeSH
• cytokininy MeSH
• dusík MeSH
• glukosinoláty MeSH
• jasmonic acid MeSH Prohlížeč
• oxylipiny MeSH
• uhlík MeSH

Hormonal dynamics after Plasmodiophora brassicae infection were compared in two Brassica napus cultivars-more resistant SY Alister and more sensitive Hornet, in order to elucidate responses associated with efficient defense. Both cultivars responded to infection by the early transient elevation of active cytokinins (predominantly cis-zeatin) and auxin indole-3-acetic acid (IAA) in leaves and roots, which was longer in Hornet. Moderate IAA levels in Hornet roots coincided with a high expression of biosynthetic gene nitrilase NIT1 (contrary to TAA1, YUC8, YUC9). Alister had a higher basal level of salicylic acid (SA), and it stimulated its production (via the expression of isochorismate synthase (ICS1)) in roots earlier than Hornet. Gall formation stimulated cytokinin, auxin, and SA levels-with a maximum 22 days after inoculation (dai). SA marker gene PR1 expression was the most profound at the time point where gall formation began, in leaves, roots, and especially in galls. Jasmonic acid (JA) was higher in Hornet than in Alister during the whole experiment. To investigate SA and JA function, SA was applied before infection, and twice (before infection and 15 dai), and JA at 15 dai. Double SA application diminished gall formation in Alister, and JA promoted gall formation in both cultivars. Activation of SA/JA pathways reflects the main differences in clubroot resistance.

• Klíčová slova
• Brassica napus, Plasmodiophora brassicae, auxin, cytokinin, gene expression, jasmonic acid, plant hormone, resistance, salicylic acid,
• MeSH
• aminohydrolasy genetika   MeSH
• Brassica napus růst a vývoj   metabolismus   parazitologie   MeSH
• cyklopentany analýza   MeSH
• cytokininy analýza   MeSH
• intramolekulární transferasy genetika   MeSH
• kořeny rostlin růst a vývoj   metabolismus   parazitologie   MeSH
• kyseliny indoloctové analýza   MeSH
• listy rostlin růst a vývoj   metabolismus   parazitologie   MeSH
• nemoci rostlin parazitologie   MeSH
• odolnost vůči nemocem MeSH
• oxylipiny analýza   MeSH
• Plasmodiophorida patogenita   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin analýza   MeSH
• rostlinné proteiny genetika   MeSH
• vývojová regulace genové exprese MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• aminohydrolasy MeSH
• cyklopentany MeSH
• cytokininy MeSH
• intramolekulární transferasy MeSH
• isochorismate synthase MeSH Prohlížeč
• jasmonic acid MeSH Prohlížeč
• kyseliny indoloctové MeSH
• nitrilase MeSH Prohlížeč
• oxylipiny MeSH
• regulátory růstu rostlin MeSH
• rostlinné proteiny MeSH

Fungi, nematodes and oomycetes belong to the most prominent eukaryotic plant pathogenic organisms. Unicellular organisms from other eukaryotic lineages, commonly addressed as protists, also infect plants. This review provides an introduction to plant pathogenic protists, including algae infecting oomycetes, and their current state of research.

• Klíčová slova
• algae, phytomonas, phytomyxae, plant pathogens, plasmodiophorids, protist, stramenopiles,
• MeSH
• oomycety patogenita   MeSH
• Plasmodiophorida patogenita   MeSH
• rostliny mikrobiologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH