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
Actin cytoskeleton is the fundamental structural component of eukaryotic cells. It has a role in numerous elementary cellular processes such as reproduction, development and also in response to abiotic and biotic stimuli. Remarkably, the role of actin cytoskeleton in plant response to pathogens is getting to be under magnifying glass. Based on microscopic studies, most of the data showed, that actin plays an important role in formation of physiological barrier in the site of infection. Actin dynamics is involved in the transport of antimicrobial compounds and cell wall fortifying components (e.g. callose) to the site of infection. Also the role in PTI (pathogen triggered immunity) and ETI (effector triggered immunity) was recently indicated. On the other hand much less is known about the transcriptome reprogramming upon changes in actin dynamics. Our recently published results showed that drugs inhibiting actin polymerization (latrunculin B, cytochalasin E) cause the induction of genes which are involved in salicylic acid (SA) signaling pathway. In this addendum we would like to highlight in more details current state of knowledge concerning the involvement of actin dynamics in plant defense signaling.
Growth is the best visible sign of plant comfort. If plants are under stress, a difference in growth with control conditions can indicate that something is going wrong (or better). Phytohormones such as auxin, cytokinins, brassinosteroids or giberellins, are important growth regulators and their role in plant growth was extensively studied. On the other hand the role of salicylic acid (SA), a phytohormone commonly connected with plant defense responses, in plant growth is under-rated. However, studies with SA-overaccumulating mutants directly showed an influence of SA on plant growth. Recently we characterized an Arabidopsis SA-overaccumulating mutant impaired in phosphatidylinositol-4-kinases (pi4kIIIβ1β2). This mutant is dwarf. The crossing with mutants impaired in SA signaling revealed that pi4kIIIβ1β2 stunted rosette is due to high SA, while the short root length is not. This brings into evidence that upper and lower parts of the plants, even though they may share common phenotypes, are differently regulated.
- MeSH
- 1-fosfatidylinositol-4-kinasa genetika MeSH
- Arabidopsis anatomie a histologie enzymologie MeSH
- kořeny rostlin anatomie a histologie MeSH
- kyselina salicylová metabolismus MeSH
- listy rostlin anatomie a histologie MeSH
- mutace genetika MeSH
- proteiny huseníčku genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Napadení zemědělsky významných rostlin patogeny patří mezi důležité faktory snižující jejich výnos. Jedním ze způsobů jak tomuto problému čelit, je pochopit molekulární mechanismy obranných reakcí rostlin při napadení a umět této znalosti využít. Při infekci rostlin patří mezi klíčové molekuly kyselina salicylová. Studium signální dráhy SA ukázalo, že tato látka je součástí systémově získané rezistence a že není pouze lineární drahou, ba naopak, že je velmi těsně provázána i s jinými fytohormonálními signálními drahami. V nedávné době byly konečně popsány receptory SA, kterými jsou proteiny NPR3 a NPR4. Zajímavostí je, že BTH (benzothiadiazol), funkční analog SA, je komerčně prodáván jako induktor rezistence rostlin vůči patogenům.
Infestation of crops by pathogens belongs among the major factors decreasing their yield. One way how to solve that problem is to understand the plant‘s defense against infection and be able to take advantage of this knowledge. Salicylic acid is a key molecule participating in the defense against infection. In the study of SA signalling pathway it was shown that SA is a part of systemic acquired resistance and that this is not only a linear path; on the contrary, SA signalling is very closely connected with the pathways mediated by other fytohormons. In the year 2012 NPR3 and NPR4 proteins were described as receptors for SA. Interestingly BTH (benzothiadiazole), functional analog of SA, is commercially used as the induktor which enhances the resistance plants toward pathogens.
- MeSH
- apoptóza MeSH
- cyklopentany MeSH
- fyziologie rostlin MeSH
- kyselina alfa-linolenová * analogy a deriváty MeSH
- kyselina salicylová * MeSH
- lidé MeSH
- mediátory zánětu MeSH
- oxylipiny MeSH
- patogeny v krvi izolace a purifikace MeSH
- prostaglandiny MeSH
- regulace genové exprese u rostlin MeSH
- regulátory růstu rostlin * MeSH
- rostliny MeSH
- signální transdukce MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Phosphoglycerolipids are essential structural constituents of membranes and some also have important cell signalling roles. In this review, we focus on phosphoglycerolipids that are mediators in hormone signal transduction in plants. We first describe the structures of the main signalling phosphoglycerolipids and the metabolic pathways that generate them, namely the phospholipase and lipid kinase pathways. In silico analysis of Arabidopsis transcriptome data provides evidence that the genes encoding the enzymes of these pathways are transcriptionally regulated in responses to hormones, suggesting some link with hormone signal transduction. The involvement of phosphoglycerolipid signalling in the early responses to abscisic acid, salicylic acid and auxins is then detailed. One of the most important signalling lipids in plants is phosphatidic acid. It can activate or inactivate protein kinases and/or protein phosphatases involved in hormone signalling. It can also activate NADPH oxidase leading to the production of reactive oxygen species. We will interrogate the mechanisms that allow the activation/deactivation of the lipid pathways, in particular the roles of G proteins and calcium. Mediating lipids thus appear as master players of cell signalling, modulating, if not controlling, major transducing steps of hormone signals.
- MeSH
- Arabidopsis fyziologie MeSH
- fosfolipasy metabolismus MeSH
- fosfotransferasy metabolismus MeSH
- glycerofosfolipidy metabolismus MeSH
- kyselina abscisová metabolismus MeSH
- kyseliny fosfatidové metabolismus MeSH
- regulace genové exprese u rostlin MeSH
- regulátory růstu rostlin metabolismus MeSH
- rostlinné proteiny metabolismus MeSH
- rostliny MeSH
- signální transdukce fyziologie MeSH
- transkriptom MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
