Cytokinins are plant hormones with biological functions ranging from coordination of plant growth to the regulation of biotic and abiotic stress-related responses and senescence. The components of the plant immune system can learn from past elicitations by microbial pathogens and herbivores and adapt to new threats. It is known that plants can enter the primed state of enhanced defense induced by either natural or synthetic compounds. While the involvement of cytokinins in defense priming has been documented, no comprehensive model of their action has been provided to date. Here, we report the functional characterization of two aromatic cytokinin derivatives, 6-benzylaminopurine-9-arabinosides (BAPAs), 3-methoxy-BAPA and 3-hydroxy-BAPA, that proved to be effective in delaying senescence in detached leaves while having low interactions with the cytokinin pathway. An RNA-seq profiling study on Arabidopsis leaves treated with 3-methoxy-BAPA revealed that short and extended treatments with this compound shifted the transcriptional response markedly toward defense. Both treatments revealed upregulation of genes involved in processes associated with plant innate immunity such as cell wall remodeling and upregulation of specific MAP kinases, most importantly MPK11, which is a MAPK module involved in stress-related signaling during the pathogen-associated molecular patterns (PAMPs) response. In addition, elevated levels of JA and its metabolites, jasmonate/ethylene-driven upregulation of PLANT DEFENSIN 1.2 (PDF1.2) and other defensins, and also temporarily elevated levels of reactive oxygen species marked the plant response to 3-methoxy-BAPA treatment. Synergistic interactions were observed when plants were cotreated with 3-hydroxy-BAPA and the flagellin-derived bacterial PAMP peptide (flg22), leading to the enhanced expression of the PAMP-triggered immunity (PTI) marker gene FRK1. Our data collectively show that some BAPAs can sensitively prime the PTI responses in a low micromolar range of concentrations while having no observable negative effects on the overall fitness of the plant.

• MeSH
• Arabidopsis chemie   metabolismus   MeSH
• arabinonukleosidy chemie   farmakologie   MeSH
• cytokininy chemie   farmakologie   MeSH
• imunita rostlin účinky léků   MeSH
• listy rostlin účinky léků   MeSH
• MAP kinasový signální systém účinky léků   MeSH
• mitogenem aktivované proteinkinasy genetika   metabolismus   MeSH
• molekulární struktura MeSH
• PAMP struktury farmakologie   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Studying stress pathways on the level of secondary metabolites that are found in very small concentration in the cells is complicated. In the algae, the role of individual metabolites (such as carotenoids, phenolic compounds, organic acids, and vitamins) and miRNAs that participate in plant's defence are very poorly understood during stressful conditions. Therefore, in the present experiment, the model organism Chlamydomonas reinhardtii was exposed to stress conditions (Lyc and UV-C irradiation) to detect these substances, even at very low concentrations. The purpose was to monitored changes at each response level with a future view to identifying their specific roles under different stress factors. In stress-treated cultures, numerous transcriptomic and metabolomic pathways were triggered in C. reinhardtii. Although Lyc significantly decreased the concentration of AA, suggesting that Lyc has a similar function in C. reinhardtii as in plants. The negative effect of UV-C radiation was based on the production of ROS and enhancement of antioxidant responses, resulting in increased levels of polyphenols and simple phenolic compounds. Both treatments did lead to extensive changes in transcript levels and miRNA expression patterns.

• MeSH
• alkaloidy amarylkovitých farmakologie   MeSH
• Chlamydomonas reinhardtii účinky léků   genetika   metabolismus   účinky záření   MeSH
• fenantridiny farmakologie   MeSH
• mikro RNA * MeSH
• polyfenoly metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulace genové exprese u rostlin účinky léků   účinky záření   MeSH
• RNA rostlin * MeSH
• ultrafialové záření * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Hydrogen peroxide promotes seed germination, but the molecular mechanisms underlying this process are unclear. This study presents the results of eggplant (Solanum melongena) germination analyses conducted at two different temperatures and follows the effect of hydrogen peroxide treatment on seed germination and the seed proteome. Hydrogen peroxide was found to promote eggplant germination in a way not dissimilar to that of increased temperature stimuli. LC-MS profiling detected 729 protein families, 77 of which responded to a temperature increase or hydrogen peroxide treatment. These differentially abundant proteins were found to be involved in a number of processes, including protein and amino acid metabolism, carbohydrate metabolism, and the glyoxylate cycle. There was a very low overlap between hydrogen peroxide and temperature-responsive proteins, highlighting the differences behind the seemingly similar outcomes. Furthermore, the observed changes from the seed proteome indicate that hydrogen peroxide treatment diminished the seed endogenous hydrogen peroxide pool and that a part of manifested positive hydrogen peroxide effect might be related to altered sensitivity to abscisic acid.

• MeSH
• chromatografie kapalinová MeSH
• fyziologický stres účinky léků   MeSH
• hmotnostní spektrometrie MeSH
• klíčení účinky léků   MeSH
• metabolismus sacharidů účinky léků   MeSH
• peroxid vodíku farmakologie   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• rostlinné proteiny metabolismus   MeSH
• Solanum melongena účinky léků   fyziologie   MeSH
• teplota MeSH
• vývojová regulace genové exprese účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH

S-nitrosoglutathione reductase (GSNOR) exerts crucial roles in the homeostasis of nitric oxide (NO) and reactive nitrogen species (RNS) in plant cells through indirect control of S-nitrosation, an important protein post-translational modification in signaling pathways of NO. Using cultivated and wild tomato species, we studied GSNOR function in interactions of key enzymes of reactive oxygen species (ROS) metabolism with RNS mediated by protein S-nitrosation during tomato root growth and responses to salinity and cadmium. Application of a GSNOR inhibitor N6022 increased both NO and S-nitrosothiol levels and stimulated root growth in both genotypes. Moreover, N6022 treatment, as well as S-nitrosoglutathione (GSNO) application, caused intensive S-nitrosation of important enzymes of ROS metabolism, NADPH oxidase (NADPHox) and ascorbate peroxidase (APX). Under abiotic stress, activities of APX and NADPHox were modulated by S-nitrosation. Increased production of H2O2 and subsequent oxidative stress were observed in wild Solanumhabrochaites, together with increased GSNOR activity and reduced S-nitrosothiols. An opposite effect occurred in cultivated S. lycopersicum, where reduced GSNOR activity and intensive S-nitrosation resulted in reduced ROS levels by abiotic stress. These data suggest stress-triggered disruption of ROS homeostasis, mediated by modulation of RNS and S-nitrosation of NADPHox and APX, underlies tomato root growth inhibition by salinity and cadmium stress.

• MeSH
• aldehydoxidoreduktasy metabolismus   MeSH
• askorbátperoxidasa metabolismus   MeSH
• benzamidy chemie   metabolismus   farmakologie   MeSH
• chlorid sodný farmakologie   MeSH
• fyziologický stres MeSH
• kadmium toxicita   MeSH
• kořeny rostlin účinky léků   růst a vývoj   metabolismus   MeSH
• NADPH-oxidasy metabolismus   MeSH
• nitrosace MeSH
• oxid dusnatý metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• peroxid vodíku metabolismus   MeSH
• pyrroly chemie   metabolismus   farmakologie   MeSH
• reaktivní formy dusíku chemie   metabolismus   MeSH
• reaktivní formy kyslíku chemie   metabolismus   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• rostlinné proteiny metabolismus   MeSH
• S-nitrosoglutathion farmakologie   MeSH
• S-nitrosothioly metabolismus   MeSH
• Solanum lycopersicum účinky léků   růst a vývoj   metabolismus   MeSH
• Solanum růst a vývoj   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Singlet oxygen produced from triplet excited chlorophylls in photosynthesis is a signal molecule that can induce programmed cell death (PCD) through the action of the OXIDATIVE STRESS INDUCIBLE 1 (OXI1) kinase. Here, we identify two negative regulators of light-induced PCD that modulate OXI1 expression: DAD1 and DAD2, homologs of the human antiapoptotic protein DEFENDER AGAINST CELL DEATH. Overexpressing OXI1 in Arabidopsis (Arabidopsis thaliana) increased plant sensitivity to high light and induced early senescence of mature leaves. Both phenomena rely on a marked accumulation of jasmonate and salicylate. DAD1 or DAD2 overexpression decreased OXI1 expression, jasmonate levels, and sensitivity to photooxidative stress. Knock-out mutants of DAD1 or DAD2 exhibited the opposite responses. Exogenous applications of jasmonate upregulated salicylate biosynthesis genes and caused leaf damage in wild-type plants but not in the salicylate biosynthesis mutant Salicylic acid induction-deficient2, indicating that salicylate plays a crucial role in PCD downstream of jasmonate. Treating plants with salicylate upregulated the DAD genes and downregulated OXI1 We conclude that OXI1 and DAD are antagonistic regulators of cell death through modulating jasmonate and salicylate levels. High light-induced PCD thus results from a tight control of the relative activities of these regulating proteins, with DAD exerting a negative feedback control on OXI1 expression.

• MeSH
• apoptóza genetika   účinky záření   MeSH
• Arabidopsis cytologie   genetika   metabolismus   MeSH
• biosyntetické dráhy účinky léků   genetika   účinky záření   MeSH
• cyklopentany metabolismus   farmakologie   MeSH
• fosfolipasy A1 genetika   metabolismus   MeSH
• kyselina salicylová metabolismus   farmakologie   MeSH
• listy rostlin cytologie   genetika   metabolismus   MeSH
• mutace MeSH
• oxylipiny metabolismus   farmakologie   MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin účinky léků   účinky záření   MeSH
• regulátory růstu rostlin metabolismus   farmakologie   MeSH
• singletový kyslík metabolismus   MeSH
• stanovení celkové genové exprese metody   MeSH
• světlo MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Recognition of pathogen-associated molecular patterns (PAMPs) is crucial for plant defence against pathogen attack. The best characterized PAMP is flg22, a 22 amino acid conserved peptide from flagellin protein. In Arabidopsis thaliana, flg22 is recognized by the flagellin sensing 2 (FLS2) receptor. In this study, we focused on biotic stress responses triggered by flg22 after exposure to temporary heat stress (HS). It is important to study the reactions of plants to multiple stress conditions because plants are often exposed simultaneously to a combination of both abiotic and biotic stresses. Transient early production of reactive oxygen species (ROS) is a well-characterized response to PAMP recognition. We demonstrate the strong reduction of flg22-induced ROS production in A. thaliana after HS treatment. In addition, a decrease in FLS2 transcription and a decrease of the FLS2 presence at the plasma membrane are shown after HS. In summary, our data show the strong inhibitory effect of HS on flg22-triggered events in A. thaliana. Subsequently, temporary HS strongly decreases the resistance of A. thaliana to Pseudomonas syringae. We propose that short exposure to high temperature is a crucial abiotic stress factor that suppresses PAMP-triggered immunity, which subsequently leads to the higher susceptibility of plants to pathogens.

• MeSH
• alarminy metabolismus   MeSH
• Arabidopsis účinky léků   genetika   imunologie   mikrobiologie   MeSH
• flagelin farmakologie   MeSH
• genetická transkripce účinky léků   MeSH
• imunita rostlin * účinky léků   MeSH
• nemoci rostlin imunologie   mikrobiologie   MeSH
• odolnost vůči nemocem imunologie   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• Pseudomonas syringae účinky léků   fyziologie   MeSH
• reakce na tepelný šok * účinky léků   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• respirační vzplanutí účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Uptake of water and nutrients by roots affects the ontogenesis of the whole plant. Nanoparticles, e.g. gold nanoparticles, have a broad range of applications in many fields which leads to the transfer of these materials into the environment. Thus, the understanding of their impact on the growth and development of the root system is an emerging issue. During our studies on the effect of positively charged gold nanoparticles on the barley roots, a hairless phenotype was found. We investigated whether this phenotype correlates with changes in symplasmic communication, which is an important factor that regulates, among others, differentiation of the rhizodermis into hair and non-hair cells. The results showed no restriction in symplasmic communication in the treated roots, in contrast to the control roots, in which the trichoblasts and atrichoblasts were symplasmically isolated during their differentiation. Moreover, differences concerning the root morphology, histology, ultrastructure and the cell wall composition were detected between the control and the treated roots. These findings suggest that the harmful effect of nanoparticles on plant growth may, among others, consist in disrupting the symplasmic communication/isolation, which leads to the development of a hairless root phenotype, thus limiting the functioning of the roots.

• MeSH
• buněčná diferenciace účinky léků   MeSH
• buněčná membrána metabolismus   MeSH
• epidermis rostlin cytologie   účinky léků   metabolismus   MeSH
• ječmen (rod) účinky léků   genetika   růst a vývoj   metabolismus   MeSH
• kořeny rostlin cytologie   účinky léků   růst a vývoj   metabolismus   MeSH
• kovové nanočástice toxicita   MeSH
• látky znečišťující půdu toxicita   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• semenáček účinky léků   růst a vývoj   MeSH
• voda metabolismus   MeSH
• živiny metabolismus   MeSH
• zlato toxicita   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Systemin (SYS), an octadecapeptide hormone processed from a 200-amino-acid precursor (prosystemin, PS), plays a central role in the systemic activation of defense genes in tomato in response to herbivore and pathogen attacks. However, whether PS mRNA is transferable and its role in systemic defense responses remain unknown. We created the transgenic tomato PS gene tagged with the green fluorescent protein (PS-GFP) using a shoot- or root-specific promoter, and the constitutive 35S promoter in Arabidopsis. Subcellular localization of PS-/SYS-GFP was observed using confocal laser scanning microscopy and gene transcripts were determined using quantitative real-time PCR. In Arabidopsis, PS protein can be processed and SYS is secreted. Shoot-/root-specific expression of PS-GFP in Arabidopsis, and grafting experiments, revealed that the PS mRNA moves in a bi-directional manner. We also found that ectopic expression of PS improves Arabidopsis resistance to the necrotrophic fungus Botrytis cinerea, consistent with substantial upregulation of the transcript levels of specific pathogen-responsive genes. Our results provide novel insights into the multifaceted mechanism of SYS signaling transport and its potential application in genetic engineering for increasing pathogen resistance across diverse plant families.

• MeSH
• Arabidopsis účinky léků   genetika   mikrobiologie   MeSH
• Botrytis účinky léků   fyziologie   MeSH
• fluorescence MeSH
• geneticky modifikované rostliny MeSH
• kořeny rostlin účinky léků   genetika   MeSH
• messenger RNA genetika   metabolismus   MeSH
• nemoci rostlin genetika   mikrobiologie   MeSH
• odolnost vůči nemocem účinky léků   genetika   MeSH
• peptidy farmakologie   MeSH
• proteolýza účinky léků   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• semenáček účinky léků   růst a vývoj   fyziologie   MeSH
• Solanum lycopersicum mikrobiologie   MeSH
• subcelulární frakce metabolismus   MeSH
• transport RNA účinky léků   genetika   MeSH
• výhonky rostlin účinky léků   genetika   MeSH
• zelené fluorescenční proteiny metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

During plant growth and defense, cell cycle activity needs to be coordinated with cell wall integrity. Little is known about how this coordination is achieved. Here, we investigated coordination in Arabidopsis thaliana seedlings by studying the impact of cell wall damage (CWD, caused by cellulose biosynthesis inhibition) on cytokinin homeostasis, cell cycle gene expression and cell shape in root tips. CWD inhibited cell cycle gene expression and increased transition zone cell width in an osmosensitive manner. These results were correlated with CWD-induced, osmosensitive changes in cytokinin homeostasis. Expression of CYTOKININ OXIDASE/DEHYDROGENASE 2 and 3 (CKX2, CKX3), which encode cytokinin-degrading enzymes, was induced by CWD and reduced by osmoticum treatment. In nitrate reductase1 nitrate reductase2 (nia1 nia2) seedlings, CKX2 and CKX3 transcript levels were not increased and cell cycle gene expression was not repressed by CWD. Moreover, established CWD-induced responses, such as jasmonic acid, salicylic acid and lignin production, were also absent, implying a central role of NIA1/2-mediated processes in regulation of CWD responses. These results suggest that CWD enhances cytokinin degradation rates through a NIA1/2-mediated process, leading to attenuation of cell cycle gene expression.

• MeSH
• Arabidopsis cytologie   účinky léků   genetika   MeSH
• benzamidy farmakologie   MeSH
• biologické modely MeSH
• buněčná stěna účinky léků   metabolismus   MeSH
• buněčný cyklus účinky léků   genetika   MeSH
• cytokininy farmakologie   MeSH
• fenotyp MeSH
• homeostáza účinky léků   MeSH
• kořeny rostlin cytologie   účinky léků   růst a vývoj   MeSH
• messenger RNA genetika   metabolismus   MeSH
• nitrátreduktasa metabolismus   MeSH
• osmóza MeSH
• proteiny huseníčku metabolismus   MeSH
• regulace genové exprese u rostlin * účinky léků   MeSH
• semenáček účinky léků   genetika   MeSH
• sorbitol farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Exposition to pharmaceutical compounds released to the environment is considered as a potential risk for various organisms. We exposed Arabidopsis thaliana plants to naproxen (NAP) and praziquantel (PZQ) in 5 µM concentration for 2 days and recorded transcriptomic response in their roots with the aim to estimate ecotoxicity and to identify gene candidates potentially involved in metabolism of both compounds. Nonsteroidal anti-inflammatory drug NAP up-regulated 105 and down-regulated 29 genes (p-value ≤ 0.1, fold change ≥ 2), while anthelmintic PZQ up-regulated 389 and down-regulated 353 genes with more rigorous p-value ≤ 0.001 (fold change ≥ 2). High number of up-regulated genes coding for heat shock proteins and other genes involved in response to biotic and abiotic stresses as well as down-regulation of genes involved in processes such as cell proliferation, transcription and water transport indicates serious negative effect of PZQ. NAP up-regulated mostly genes involved in various biological processes and signal transduction and down-regulated mainly genes involved in signal transduction and electron transport or energy pathways. Further, two cytochrome P450s (demethylation) and one methyltransferase (methylation of carboxyl group) were identified as candidates for phase I and several glutathione- and glycosyltransferases (conjugation) for phase II of NAP metabolism. Cytochrome P450s, glutathione and glycosyltransferases seem to play role also in metabolism of PZQ. Up-regulation of several ABC and MATE transporters by NAP and PZQ indicated their role in transport of both compounds.

• MeSH
• anthelmintika farmakologie   MeSH
• antiflogistika nesteroidní farmakologie   MeSH
• Arabidopsis účinky léků   metabolismus   MeSH
• biologický transport účinky léků   MeSH
• down regulace MeSH
• glutathion metabolismus   MeSH
• glykosyltransferasy metabolismus   MeSH
• kořeny rostlin metabolismus   MeSH
• methyltransferasy metabolismus   MeSH
• naproxen farmakologie   MeSH
• praziquantel farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• proteiny tepelného šoku metabolismus   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• signální transdukce účinky léků   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom účinky léků   MeSH
• transport elektronů účinky léků   MeSH
• upregulace MeSH
• Publikační typ
• časopisecké články MeSH