Plasmodiophora brassicae is one of the most devastating threats to Brassicaceae crops. However, the molecular mechanisms underlying clubroot disease remain unclear. Initial proteomics results led us to hypothesize that HSP70 proteins regulate host-P. brassicae interactions by modulating both plant defenses and pathogen activity. Using the Arabidopsis thaliana-P. brassicae model system, we studied the role of HSP70 proteins in detail. Through a combination of proteomics and mutant phenotype analyses, we indicate that Plasmodiophora infection induces HSP70 accumulation in Arabidopsis roots, and mutations in specific HSP70 isoforms either promote (HSP70-1, HSP70-13, HSP70-14) or suppress (HSP70-5, HSP70-12) the onset of clubroot disease. Proteomic profiling of root galls showed strong correlations between infection severity and pathogen-derived HSP70 protein CEO96729. Interactomics analyses revealed that CEO96729 interacts with host proteins involved in plant response to Plasmodiophora infection, including an extracellular GDSL esterase/lipase with a putative role in long-distance signaling, and that CEO96729 forms heterodimers with host HSP70 isoforms. These findings suggest that Plasmodiophora hijacks the host chaperone machinery to facilitate infection, offering a potential explanation for the observed modulation of disease progression in HSP70 mutants. Notably, the results also point to possible intracellular interactions with key enzymes in host physiology, including catalase 2, essential for ROS metabolism, and nitrilase, critical for auxin biosynthesis and root gall formation. Collectively, our study highlights the multifaceted roles of HSP70 proteins in Plasmodiophora pathogenicity and host-pathogen interactions, providing insights into chaperone-mediated processes in plant immunity and infection dynamics.

• Klíčová slova
• clubroot disease, interactomics, plant immunity, plant‐pathogen interaction, proteomics,
• MeSH
• Arabidopsis * parazitologie   genetika   metabolismus   MeSH
• interakce hostitele a patogenu * fyziologie   MeSH
• kořeny rostlin parazitologie   metabolismus   genetika   MeSH
• mutace MeSH
• nemoci rostlin * parazitologie   imunologie   MeSH
• Plasmodiophorida * fyziologie   MeSH
• proteiny huseníčku * metabolismus   genetika   MeSH
• proteiny tepelného šoku HSP70 * metabolismus   genetika   MeSH
• proteomika MeSH
• regulace genové exprese u rostlin MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• proteiny huseníčku * MeSH
• proteiny tepelného šoku HSP70 * MeSH

Xylem sap proteomics provides crucial insights into plant defense and root-to-shoot communication. This study highlights the sensitivity and reproducibility of xylem sap proteome analyses, using a single plant per sample to track over 3000 proteins in two model crop plants, Solanum tuberosum and Hordeum vulgare. By analyzing the flg22 response, we identified immune response components not detectable through root or shoot analyses. Notably, we discovered previously unknown elements of the plant immune system, including calcium/calmodulin-dependent kinases and G-type lectin receptor kinases. Despite similarities in the metabolic pathways identified in the xylem sap of both plants, the flg22 response differed significantly: S. tuberosum exhibited 78 differentially abundant proteins, whereas H. vulgare had over 450. However, an evolutionarily conserved overlap in the flg22 response proteins was evident, particularly in the CAZymes and lipid metabolism pathways, where lipid transfer proteins and lipases showed a similar response to flg22. Additionally, many proteins without conserved signal sequences for extracellular targeting were found, such as members of the HSP70 family. Interestingly, the HSP70 response to flg22 was specific to the xylem sap proteome, suggesting a unique regulatory role in the extracellular space similar to that reported in mammalians.

• Klíčová slova
• HSP70, barley, biotic interaction, exudates, potato, protein extraction, proteomics,
• Publikační typ
• časopisecké články MeSH

Parental or ancestral environments can induce heritable phenotypic changes, but whether such environment-induced heritable changes are a common phenomenon remains unexplored. Here, we subject 14 genotypes of Arabidopsis thaliana to 10 different environmental treatments and observe phenotypic and genome-wide gene expression changes over four successive generations. We find that all treatments caused heritable phenotypic and gene expression changes, with a substantial proportion stably transmitted over all observed generations. Intriguingly, the susceptibility of a genotype to environmental inductions could be predicted based on the transposon abundance in the genome. Our study thus challenges the classic view that the environment only participates in the selection of heritable variation and suggests that the environment can play a significant role in generating of heritable variations.

• MeSH
• Arabidopsis * genetika   MeSH
• fenotyp * MeSH
• genetická variace MeSH
• genom rostlinný MeSH
• genotyp * MeSH
• interakce genů a prostředí MeSH
• regulace genové exprese u rostlin * MeSH
• transpozibilní elementy DNA * genetika   MeSH
• životní prostředí MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• transpozibilní elementy DNA * MeSH

Cadmium is one of the most toxic heavy metal pollutants, and its accumulation in the soil is harmful to agriculture. Plants have a higher cadmium tolerance than animals, and some species can be used for phytoremediation. Flax (Linum usitatissimum L.) can accumulate high amounts of cadmium, but the molecular mechanism behind its tolerance is unknown. Here, we employed four genotypes representing two fiber cultivars, an oilseed breeding line, and a transgenic line overexpressing the metallothionein domain for improved cadmium tolerance. We analyzed the proteome of suspensions and the proteome and metabolome of seedling roots in response to cadmium. We identified more than 1400 differentially abundant proteins representing putative mechanisms in cadmium tolerance, including metal-binding proteins and transporters, enzymes of flavonoid, jasmonate, polyamine, glutathione metabolism, and HSP70 proteins. Our data indicated the role of the phytohormone cytokinin in the observed responses. The metabolome profiling found that pipecolinic acid could be a part of the cadmium accumulation mechanism, and the observed accumulation of putrescine, coumaric acid, cinnamic acid, and coutaric acid confirmed the role of polyamines and flavonoids in tolerance to cadmium. In conclusion, our data provide new insight into cadmium tolerance and prospective targets for improving cadmium tolerance in other plants.

• Klíčová slova
• Cd2+, HSP70, heavy metals, phenolic compounds, pipecolinic acid, polyamines, proteome, toxicity,
• Publikační typ
• časopisecké články MeSH

Poplars are among the fastest-growing trees and significant resources in agriculture and forestry. However, rapid growth requires a large water consumption, and irrigation water provides a natural means for pathogen spread. That includes members of Phytophthora spp. that have proven to be a global enemy to forests. With the known adaptability to new hosts, it is only a matter of time for more aggressive Phytophthora species to become a threat to poplar forests and plantations. Here, the effects of artificial inoculation with two different representatives of aggressive species (P. cactorum and P. plurivora) were analyzed in the proteome of the Phytophthora-tolerant hybrid poplar clone T-14 [Populus tremula L. 70 × (Populus × canescens (Ait.) Sm. 23)]. Wood microcore samples were collected at the active necrosis borders to provide insight into the molecular processes underlying the observed tolerance to Phytophthora. The analysis revealed the impact of Phytophthora on poplar primary and secondary metabolism, including carbohydrate-active enzymes, amino acid biosynthesis, phenolic metabolism, and lipid metabolism, all of which were confirmed by consecutive metabolome and lipidome profiling. Modulations of enzymes indicating systemic response were confirmed by the analysis of leaf proteome, and sampling of wood microcores in distal locations revealed proteins with abundance correlating with proximity to the infection, including germin-like proteins, components of proteosynthesis, glutamate carboxypeptidase, and an enzyme that likely promotes anthocyanin stability. Finally, the identified Phytophthora-responsive proteins were compared to those previously found in trees with compromised defense against Phytophthora, namely, Quercus spp. and Castanea sativa. That provided a subset of candidate markers of Phytophthora tolerance, including certain ribosomal proteins, auxin metabolism enzymes, dioxygenases, polyphenol oxidases, trehalose-phosphate synthase, mannose-1-phosphate guanylyltransferase, and rhamnose biosynthetic enzymes. In summary, this analysis provided the first insight into the molecular mechanisms of hybrid poplar defense against Phytophthora and identified prospective targets for improving Phytophthora tolerance in trees.

• Klíčová slova
• Phytophthora cactorum, Phytophthora plurivora, Populus, biotic interaction, lipidome, metabolome, proteome,
• Publikační typ
• časopisecké články MeSH

Pythium oligandrum, strain M1, is a soil oomycete successfully used as a biological control agent (BCA), protecting plants against fungal, yeast, and oomycete pathogens through mycoparasitism and elicitor-dependent plant priming. The not yet described Pythium strains, X42 and 00X48, have shown potential as BCAs given the high activity of their secreted proteases, endoglycosidases, and tryptamine. Here, Solanum lycopersicum L. cv. Micro-Tom seeds were coated with Pythium strains, and seedlings were exposed to fungal pathogens, either Alternaria brassicicola or Verticillium albo-atrum. The effects of both infection and seed-coating on plant metabolism were assessed by determining the activity and isoforms of antioxidant enzymes and endoglycosidases and the content of tryptamine, amino acids, and heat shock proteins. Dual culture competition testing and microscopy analysis confirmed mycoparasitism in all three Pythium strains. In turn, seed treatment significantly increased the total free amino acid content, changing their abundance in both non-infected and infected plants. In response to pathogens, plant Hsp70 and Hsp90 isoform levels also varied among Pythium strains, most likely as a strategy for priming the plant against infection. Overall, our results show in vitro mycoparasitism between Pythium strains and fungal pathogens and in planta involvement of heat shock proteins in priming.

• Klíčová slova
• antioxidants, capillary electrophoresis, fungal diseases, plant protection, seed-coating,
• Publikační typ
• časopisecké články MeSH