Plant reactions to stress vary with development stage and fitness. This study assessed the relationship between light and chilling stress in Arabidopsis acclimation. By analysing the transcriptome and proteome responses of expanding leaves subjected to varying light intensity and cold, 2251 and 2064 early response genes and proteins were identified, respectively. Many of these represent as a yet unknown part of the early response to cold, illustrating a development-dependent response to stress and duality in plant adaptations. While standard light promoted photosynthetic upregulation, plastid maintenance, and increased resilience, low light triggered a unique metabolic shift, prioritizing ribosome biogenesis and lipid metabolism and attenuating the expression of genes associated with plant immunity. The comparison of early response in young leaves with that in expanded ones showed striking differences, suggesting a sacrifice of expanded leaves to support young ones. Validations of selected DEGs in mutant background confirmed a role of HSP90-1, transcription factor FLZ13, and Phospholipase A1 (PLIP) in response to cold, and the PLIP family emerged as crucial in promoting acclimation and freezing stress tolerance. The findings highlight the dynamic mechanisms that enable plants to adapt to challenging environments and pave the way for the development of genetically modified crops with enhanced freezing tolerance.

• Klíčová slova
• acclimation, freezing tolerance, jasmonic acid, leaf development, lipidome, proteome, transcriptome,
• MeSH
• aklimatizace * fyziologie   účinky záření   MeSH
• Arabidopsis * fyziologie   účinky záření   genetika   MeSH
• fotosyntéza MeSH
• listy rostlin * fyziologie   účinky záření   genetika   MeSH
• nízká teplota * MeSH
• proteiny huseníčku metabolismus   genetika   MeSH
• proteom MeSH
• regulace genové exprese u rostlin MeSH
• světlo * MeSH
• transkriptom MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• proteiny huseníčku MeSH
• proteom MeSH

Volatile organic compounds (VOCs) function as infochemicals and are important means of communication between bacteria and plants. Bacterial VOCs can promote plant growth and protect plants against both biotic and abiotic stresses. Most studies to date have focused on VOCs from single bacterial strains; consequently, very little is known about VOCs emitted by bacterial communities and their role in modulating plant phenotypes. In this work, we showed that VOCs from a root-derived 16-strain synthetic community affect Arabidopsis growth and root system architecture, whereas VOCs from individual strains produce a range of different effects. Removal of key species from the community changed the relative abundances of other strains and altered the VOC composition; however, the effect on plant growth remained the same. We therefore concluded that bacterial VOC-induced modulation of plant responses in the rhizosphere may be an emergent property of bacterial communities, rather than merely the sum of effects exerted by individual species. In total, we detected 135 different volatiles from individual strains, with dimethyl disulfide (DMDS) being the most abundant compound emitted by the community. Correlation analysis predicted several sulfur-containing compounds to promote plant growth, and revealed that exposure to two such VOCs, along with DMDS, leads to plant growth promotion. We also identified plant mutants unresponsive to DMDS, suggesting that its mechanism of action may involve assimilation into S-methylcysteine. Finally, we propose that the ecological role of VOCs is to provide early signaling alerts that prime plants for interaction with the bacterial community through modulation of root exudate composition and accumulation of defense compounds, thereby affecting the bacterial colonization of the plants.

• Klíčová slova
• Arabidopsis, bacterial volatiles, dimethyl disulfide, plant–microbe interactions, sulfur, synthetic communities,
• MeSH
• Arabidopsis * růst a vývoj   mikrobiologie   účinky léků   MeSH
• Bacteria * metabolismus   MeSH
• kořeny rostlin * růst a vývoj   mikrobiologie   anatomie a histologie   MeSH
• rhizosféra MeSH
• těkavé organické sloučeniny * metabolismus   farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• těkavé organické sloučeniny * MeSH

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

Heavy water (D2O) is scarce in nature, and despite its physical similarity to water, D2O disrupts cellular function due to the isotope effect. While microbes can survive in nearly pure D2O, eukaryotes such as Arabidopsis thaliana are more sensitive and are unable to survive higher concentrations of D2O. To explore the underlying molecular mechanisms for these differences, we conducted a comparative proteomic analysis of E. coli, S. cerevisiae, and Arabidopsis after 180 min of growth in a D2O-supplemented media. Shared adaptive mechanisms across these species were identified, including changes in ribosomal protein abundances, accumulation of chaperones, and altered metabolism of polyamines and amino acids. However, Arabidopsis exhibited unique vulnerabilities, such as a muted stress response, lack of rapid activation of reactive oxygen species metabolism, and depletion of stress phytohormone abscisic acid signaling components. Experiments with mutants show that modulating the HSP70 pool composition may promote D2O resilience. Additionally, Arabidopsis rapidly incorporated deuterium into sucrose, indicating that photosynthesis facilitates deuterium intake. These findings provide valuable insights into the molecular mechanisms that dictate differential tolerance to D2O across species and lay the groundwork for further studies on the biological effects of uncommon isotopes, with potential implications for biotechnology and environmental science.

• Klíčová slova
• HSP70, ROS metabolism, adaptation, deuterium oxide, proteome, stress response,
• Publikační typ
• časopisecké články MeSH

Heterobasidion annosum sensu lato comprises some of the most devastating pathogens of conifers. Exploring virocontrol as a potential strategy to mitigate economic losses caused by these fungi holds promise for the future. In this study, we conducted a comprehensive screening for viruses in 98 H. annosum s.l. specimens from different regions of Czechia aiming to identify viruses inducing hypovirulence. Initial examination for dsRNA presence was followed by RNA-seq analyses using pooled RNA libraries constructed from H. annosum and Heterobasidion parviporum, with diverse bioinformatic pipelines employed for virus discovery. Our study uncovered 25 distinct ssRNA viruses, including two ourmia-like viruses, one mitovirus, one fusarivirus, one tobamo-like virus, one cogu-like virus, one bisegmented narna-like virus and one segment of another narna-like virus, and 17 ambi-like viruses, for which hairpin and hammerhead ribozymes were detected. Coinfections of up to 10 viruses were observed in six Heterobasidion isolates, whereas another six harbored a single virus. Seventy-three percent of the isolates analyzed by RNA-seq were virus-free. These findings show that the virome of Heterobasidion populations in Czechia is highly diverse and differs from that in the boreal region. We further investigated the host effects of certain identified viruses through comparisons of the mycelial growth rate and proteomic analyses and found that certain tested viruses caused growth reductions of up to 22% and significant alterations in the host proteome profile. Their intraspecific transmission rates ranged from 0% to 33%. Further studies are needed to fully understand the biocontrol potential of these viruses in planta.IMPORTANCEHeterobasidion annosum sensu lato is a major pathogen causing significant damage to conifer forests, resulting in substantial economic losses. This study is significant as it explores the potential of using viruses (virocontrol) to combat these fungal pathogens. By identifying and characterizing a diverse array of viruses in H. annosum populations from Czechia, the research opens new avenues for biocontrol strategies. The discovery of 25 distinct ssRNA viruses, some of which reduce fungal growth and alter proteome profiles, suggests that these viruses could be harnessed to mitigate the impact of Heterobasidion. Understanding the interactions between these viruses and their fungal hosts is crucial for developing effective, environmentally friendly methods to protect conifer forests and maintain ecosystem health. This study lays the groundwork for future research on the application of mycoviruses in forest disease management.

• Klíčová slova
• Heterobasidion annosum, growth rate, mycovirus, proteomics, root rot, ssRNA,
• MeSH
• Basidiomycota * MeSH
• fylogeneze MeSH
• genom virový MeSH
• mykoviry genetika   izolace a purifikace   MeSH
• nemoci rostlin virologie   mikrobiologie   MeSH
• RNA virová genetika   MeSH
• RNA-viry * genetika   izolace a purifikace   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• RNA virová 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

The vast majority of agricultural land undergoes abiotic stress that can significantly reduce agricultural yields. Understanding the mechanisms of plant defenses against stresses and putting this knowledge into practice is, therefore, an integral part of sustainable agriculture. In this review, we focus on current findings in plant resistance to four cardinal abiotic stressors-drought, heat, salinity, and low temperatures. Apart from the description of the newly discovered mechanisms of signaling and resistance to abiotic stress, this review also focuses on the importance of primary and secondary metabolites, including carbohydrates, amino acids, phenolics, and phytohormones. A meta-analysis of transcriptomic studies concerning the model plant Arabidopsis demonstrates the long-observed phenomenon that abiotic stressors induce different signals and effects at the level of gene expression, but genes whose regulation is similar under most stressors can still be traced. The analysis further reveals the transcriptional modulation of Golgi-targeted proteins in response to heat stress. Our analysis also highlights several genes that are similarly regulated under all stress conditions. These genes support the central role of phytohormones in the abiotic stress response, and the importance of some of these in plant resistance has not yet been studied. Finally, this review provides information about the response to abiotic stress in major European crop plants-wheat, sugar beet, maize, potatoes, barley, sunflowers, grapes, rapeseed, tomatoes, and apples.

• Klíčová slova
• abiotic stress, cold stress, crop, drought, heat stress, metabolites, phytohormones, salinity,
• MeSH
• Arabidopsis * genetika   MeSH
• fyziologický stres genetika   MeSH
• pěstování plodin MeSH
• reakce na tepelný šok genetika   MeSH
• regulátory růstu rostlin * MeSH
• rostliny MeSH
• Publikační typ
• časopisecké články MeSH
• metaanalýza MeSH
• přehledy MeSH
• Názvy látek
• regulátory růstu rostlin * MeSH

The reproductive stage of plant development has the most critical impact on yield. Flowering is highly sensitive to abiotic stress, and increasing temperatures and drought harm crop yields. Salicylic acid is a phytohormone that regulates flowering and promotes stress resilience in plants. However, the exact molecular mechanisms and the level of protection are far from understood and seem to be species-specific. Here, the effect of salicylic acid was tested in a field experiment with Pisum sativum exposed to heat stress. Salicylic acid was administered at two different stages of flowering, and its effect on the yield and composition of the harvested seeds was followed. Plants treated with salicylic acid produced larger seed pods, and a significant increase in dry weight was found for the plants with a delayed application of salicylic acid. The analyses of the seed proteome, lipidome, and metabolome did not show any negative impact of salicylic treatment on seed composition. Identified processes that could be responsible for the observed improvement in seed yields included an increase in polyamine biosynthesis, accumulation of storage lipids and lysophosphatidylcholines, a higher abundance of components of chromatin regulation, calmodulin-like protein, and threonine synthase, and indicated a decrease in sensitivity to abscisic acid signaling.

• Klíčová slova
• field, heat stress, lipidome, metabolome, phytohormone, proteome, seed development, stress attenuation, yield,
• MeSH
• fyziologický stres MeSH
• hrách setý * metabolismus   MeSH
• kyselina salicylová * farmakologie   metabolismus   MeSH
• rostliny metabolismus   MeSH
• semena rostlinná metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina salicylová * MeSH