Search results for "Magnaporthe"
showing 10 items of 17 documents
Unravelling the biosynthesis of pyriculol in the rice blast fungus Magnaporthe oryzae
2017
Pyriculol was isolated from the rice blast fungus Magnaporthe oryzae and found to induce lesion formation on rice leaves. These findings suggest that it could be involved in virulence. The gene MoPKS19 was identified to encode a polyketide synthase essential for the production of the polyketide pyriculol in the rice blast fungus M. oryzae. The transcript abundance of MoPKS19 correlates with the biosynthesis rate of pyriculol in a time-dependent manner. Furthermore, gene inactivation of MoPKS19 resulted in a mutant unable to produce pyriculol, pyriculariol and their dihydro derivatives. Inactivation of a putative oxidase-encoding gene MoC19OXR1, which was found to be located in the genome cl…
Visualizing fungicide action: anin vivotool for rapid validation of fungicides with target location HOG pathway
2018
BACKGROUND The mitogen-activated protein kinase MoHog1p was fused with a green fluorescent protein (GFP) in the filamentous fungus Magnaporthe oryzae. The MoHOG1::GFP mutant was found to be an excellent tool visualizing in vivo fungicide-dependent translocation of MoHog1p into the nucleus. Validation of pathway specificity was achieved by generating fluorescence-labelled MoHog1p in the ΔMohik1 'loss of function' mutant strain. RESULTS GFP-labelled MoHog1p expressed in the wildtype and in ΔMohik1 demonstrates that fludioxonil is acting on the HOG pathway and even more precisely that fungicide action is dependent on the group III histidine kinase MoHik1p. GFP-tagged MoHog1p translocated into …
Hog1p activation by marasmic acid through inhibition of the histidine kinase Sln1p
2016
BACKGROUND The histidine kinase (HK) MoHik1p within the high-osmolarity glycerol (HOG) pathway is known to be the target of the fungicide fludioxonil. Treatment of the fungus with fludioxonil causes an uncontrolled hyperactivation of the pathway and cell death. In this study, we used a target-based in vivo test system with mutant strains of the rice blast fungus Magnaporthe oryzae to search for new fungicidal compounds having various target locations within the HOG pathway. Mutants with inactivated HOG signalling are resistant to fungicides having the target located in the HOG pathway. RESULTS The HK MoSln1p was identified as being involved in the new antifungal mode of action of marasmic a…
Fungicide resistance towards fludioxonil conferred by overexpression of the phosphatase gene Mo PTP 2 in Magnaporthe oryzae
2018
The fungicide fludioxonil causes hyperactivation of the Hog1p MAPK within the high-osmolarity glycerol signaling pathway essential for osmoregulation in pathogenic fungi. The molecular regulation of MoHog1p phosphorylation is not completely understood in pathogenic fungi. Thus, we identified and characterized the putative MoHog1p-interacting phosphatase gene MoPTP2 in the filamentous rice pathogen Magnaporthe oryzae. We found overexpression of MoPTP2 conferred fludioxonil resistance in M. oryzae, whereas the 'loss of function' mutant ΔMoptp2 was more susceptible toward the fungicide. Additionally, quantitative phosphoproteome profiling of MoHog1p phosphorylation revealed lower phosphorylati…
Fungal genes related to calcium homeostasis and signalling are upregulated in symbiotic arbuscular mycorrhiza interactions
2012
Fluctuations in intracellular calcium levels generate signalling events and regulate different cellular processes. Whilst the implication of Ca2+ in plant responses during arbuscular mycorrhiza (AM) interactions is well documented, nothing is known about the regulation or role of this secondary messenger in the fungal symbiont. The spatio-temporal expression pattern of putatively Ca2+-related genes of Glomus intraradices BEG141 encoding five proteins involved in membrane transport and one nuclear protein kinase, was investigated during the AM symbiosis. Expression profiles related to successful colonization of host roots were observed in interactions of G. intraradices with roots of wild-ty…
A Target-Based In Vivo Test System to Identify Novel Fungicides with Mode of Action in the HOG Pathway
2021
Resistance management plays a key role in modern plant protection. There is a growing need to identify new fungicide targets and new modes of action. In this context, it is also mandatory to find new compounds acting on successful target locations. For the latter, so-called target-site-specific test systems emerged to search for inhibitors. Most of them are based on in vitro assays, in which interaction between a compound and a purified target protein is demonstrated. Consequently, getting essential information about potentially toxic effects in the living cell or in the whole organism is not possible. Thus, we present a fluorescent-labelled mutant strain of the rice blast fungus Magnaporth…
High osmolarity glycerol (HOG) signalling in Magnaporthe oryzae: Identification of MoYPD1 and its role in osmoregulation, fungicide action, and patho…
2015
AbstractThis study comprises a first functional analysis of an YPD1-homologue in filamentous phytopathogenic fungi and its role in the HOG signalling pathway. We generated a gene deletion mutant of the gene MoYPD1 in Magnaporthe oryzae and characterized the resulting mutant strain. We have shown that MoYpd1p is a component of the phosphorelay system acting in the HOG pathway due to its Y2H protein interaction with the HKs MoHik1p and MoSln1p as well as with the response regulator MoSsk1p. Fungicidal activity of fludioxonil was reported to be based on the inhibition of MoHik1p resulting in hyperactivation of the HOG signalling pathway and lethality. Western analysis proved that both, osmotic…
Rapid adaptation of signaling networks in the fungal pathogen Magnaporthe oryzae
2019
Abstract Background One fundamental question in biology is how the evolution of eukaryotic signaling networks has taken place. “Loss of function” (lof) mutants from components of the high osmolarity glycerol (HOG) signaling pathway in the filamentous fungus Magnaporthe oryzae are viable, but impaired in osmoregulation. Results After long-term cultivation upon high osmolarity, stable individuals with reestablished osmoregulation capacity arise independently from each of the mutants with inactivated HOG pathway. This phenomenon is extremely reproducible and occurs only in osmosensitive mutants related to the HOG pathway – not in other osmosensitive Magnaporthe mutants. The major compatible so…
Histidine kinases mediate differentiation, stress response, and pathogenicity in Magnaporthe oryzae.
2014
The aim of this study is a functional characterization of 10 putative histidine kinases (HIKs)-encoding genes in the phytopathogenic fungus Magnaporthe oryzae. Two HIKs were found to be required for pathogenicity in the fungus. It was found that the mutant strains ΔMohik5 and ΔMohik8 show abnormal conidial morphology and furthermore ΔMohik5 is unable to form appressoria. Both HIKs MoHik5p and MoHik8p appear to be essential for pathogenicity since the mutants fail to infect rice plants. MoSln1p and MoHik1p were previously reported to be components of the HOG pathway in M. oryzae. The ΔMosln1 mutant is more susceptible to salt stress compared to ΔMohik1, whereas ΔMohik1 appears to be stronger…
Evidence of a New MoYpd1p Phosphotransferase Isoform in the Multistep Phosphorelay System of Magnaporthe oryzae
2021
Different external stimuli are perceived by multiple sensor histidine kinases and transmitted by phosphorylation via the phosphotransfer protein Ypd1p in the multistep phosphorelay system of the high osmolarity glycerol signaling pathway of filamentous fungi. How the signal propagation takes place is still not known in detail since multiple sensor histidine kinase genes in most filamentous fungi are coded in the genome, whereas only one gene for Ypd1p exists. That raises the hypothesis that various Ypd1p isoforms are produced from a single gene sequence, perhaps by alternative splicing, facilitating a higher variability in signal transduction. We found that the mRNA of MoYPD1 in the rice bl…