scholarly journals Cytokinin Metabolism of Pathogenic Fungus Leptosphaeria maculans Involves Isopentenyltransferase, Adenosine Kinase and Cytokinin Oxidase/Dehydrogenase

2017 ◽  
Vol 8 ◽  
Author(s):  
Lucie Trdá ◽  
Monika Barešová ◽  
Vladimír Šašek ◽  
Miroslava Nováková ◽  
Lenka Zahajská ◽  
...  
Keyword(s):  
Pathogenic Fungus ◽  
Leptosphaeria Maculans ◽  
Adenosine Kinase ◽  
Cytokinin Oxidase ◽  
Cytokinin Metabolism

The phytopathogenic fungi Leptosphaeria maculans and Leptosphaeria biglobosa: chemotaxonomical characterization of isolates and metabolite production in different culture media

2007 ◽  
Vol 53 (3) ◽  
pp. 364-371 ◽  
Author(s):  
M.  Soledade C. Pedras ◽  
Paulos B. Chumala ◽  
Yang Yu
Keyword(s):  
Culture Media ◽  
Pathogenic Fungus ◽  
Leptosphaeria Maculans ◽  
Defined Medium ◽  
Phytopathogenic Fungi ◽  
Potato Dextrose Broth ◽  
Chemical Structures ◽  
Morphologic Characteristics ◽  
Metabolite Profiles ◽  
Leptosphaeria Biglobosa

Previous molecular chemotaxonomic analyses of isolates of the plant pathogenic fungus Leptosphaeria maculans (Desm.) Ces. et de Not. (asexual stage Phoma lingam (Tode ex Fr.) Desm.) in a chemically defined medium suggested that this species complex was composed of at least three distinct groups. Subsequently, a group within L. maculans was classified as Leptosphaeria biglobosa , on the basis of morphologic characteristics and the lack of sexual crossing. To obtain clarification regarding the metabolite profiles of the various groups or species of blackleg fungi, the objectives of this work were (i) to determine the chemical structures of metabolites produced by Canadian V isolates and Polish-type isolates in potato dextrose broth (PDB) and (ii) to determine the chemotaxonomic relationship among French isolates of L. biglobosa and among Canadian W isolates and Thlaspi isolates of L. maculans. Here, we report for the first time that Canadian V isolates grown in PDB produced 2,4-dihydroxy-3,6-dimethylbenzaldehyde, a metabolite never reported from L. maculans, but none of the usual phytotoxins (sirodesmins). In addition, we report a new metabolite, 2-[2-(5-hydroxybenzofuranyl)]-3-(4-hydroxyphenyl)propanenitrile, from Polish-type isolates of L. maculans grown in PDB and the metabolite profiles of 16 Thlaspi isolates. The metabolite profiles of Thlaspi isolates indicate that these are part of two distinct groups, the Polish W group and the Canadian W group, i.e., L. biglobosa. Finally, we demonstrate that the metabolite profiles of the French isolates classified as L. biglobosa are similar to those of Canadian W isolates.

scholarly journals Isocitrate Lyase Is Essential for Pathogenicity of the Fungus Leptosphaeria maculans to Canola (Brassica napus)

2002 ◽  
Vol 1 (5) ◽  
pp. 719-724 ◽  
Author(s):  
Alexander Idnurm ◽  
Barbara J. Howlett
Keyword(s):  
Brassica Napus ◽  
Reverse Genetics ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Pathogenic Fungus ◽  
Leptosphaeria Maculans ◽  
Bacterial Pathogen ◽  
Hygromycin Resistance ◽  
Wild Type ◽  
Glyoxylate Pathway

ABSTRACT A pathogenicity gene has been identified in Leptosphaeria maculans, the ascomycetous fungus that causes blackleg disease of canola (Brassica napus). This gene encodes isocitrate lyase, a component of the glyoxylate cycle, and is essential for the successful colonization of B. napus. It was identified by a reverse genetics approach whereby a plasmid conferring hygromycin resistance was inserted randomly into the L. maculans genome. Twelve of 516 transformants tested had reduced pathogenicity on cotyledons of B. juncea and B. napus, and 1 of these 12 had a deletion of the isocitrate lyase gene, as well as an insertion of the hygromycin resistance gene. This mutant was unable to grow on fatty acids, including monolaurate, and the isocitrate lyase transcript was not detected. When the wild-type gene was reintroduced into the mutant, growth on monolaurate was restored and pathogenicity was partially restored. L. maculans isocitrate lyase is produced during infection of B. napus cotyledons, while the plant homologue is not. When 2.5% glucose was added to the inoculum of the isocitrate lyase mutant, lesions of sizes similar to those caused by wild-type isolate M1 developed on B. napus cotyledons. These findings suggest that the glyoxylate pathway is essential for disease development by this plant-pathogenic fungus, as has been shown recently for a fungal and bacterial pathogen of animals and a bacterial pathogen of plants. Involvement of the glyoxylate pathway in pathogenesis in animals and plants presents potential drug targets for control of diseases.

scholarly journals Salt Stress Induces Production of Melanin Related Metabolites in the Phytopathogenic Fungus Leptosphaeria Maculans

2009 ◽  
Vol 4 (1) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
M. Soledade C. Pedras ◽  
Yang Yu
Keyword(s):  
Salt Stress ◽  
Pathogenic Fungus ◽  
Leptosphaeria Maculans ◽  
2D Nmr ◽  
Phytopathogenic Fungus ◽  
Chemical Transformations ◽  
Melanin Biosynthesis ◽  
Protection Mechanism ◽  
Chemical Structures ◽  
Stress Metabolites

A search for stress metabolites produced by the plant pathogenic fungus Leptosphaeria maculans (asexual stage Phoma lingam) cultured in high salt medium led to the isolation and structure elucidation of two metabolites associated with melanin biosynthesis and cell melanization, a self-protection mechanism against salt stress. The chemical structures of the metabolites were deduced by detailed analysis of 1D and 2D NMR spectroscopic data and chemical transformations.

scholarly journals Constitutive expression of transcription factor SirZ blocks pathogenicity in Leptosphaeria maculans independently of sirodesmin production

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252333
Author(s):  
Andrew S. Urquhart ◽  
Candace E. Elliott ◽  
Wei Zeng ◽  
Alexander Idnurm
Keyword(s):  
Transcription Factor ◽  
Pathogenic Fungus ◽  
Leptosphaeria Maculans ◽  
Constitutive Expression ◽  
Blackleg Disease ◽  
Gene Encoding ◽  
Over Expression ◽  
Expression Construct ◽  
New Strategies

Sirodesmin, the major secondary metabolite produced by the plant pathogenic fungus Leptosphaeria maculans in vitro, has been linked to disease on Brassica species since the 1970s, and yet its role has remained ambiguous. Re-examination of gene expression data revealed that all previously described genes and two newly identified genes within the sir gene cluster in the genome are down-regulated during the crucial early establishment stages of blackleg disease on Brassica napus. To test if this is a strategy employed by the fungus to avoid damage to and then detection by the host plant during the L. maculans asymptomatic biotrophic phase, sirodesmin was produced constitutively by overexpressing the sirZ gene encoding the transcription factor that coordinates the regulation of the other genes in the sir cluster. The sirZ over-expression strains had a major reduction in pathogenicity. Mutation of the over-expression construct restored pathogenicity. However, mutation of two genes, sirP and sirG, required for specific steps in the sirodesmin biosynthesis pathway, in the sirZ over-expression background resulted in strains that were unable to synthesize sirodesmin, yet were still non-pathogenic. Elucidating the basis for this pathogenicity defect or finding ways to overexpress sirZ during disease may provide new strategies for the control of blackleg disease.

scholarly journals Cloning and characterization of an adenosine kinase fromPhyscomitrellainvolved in cytokinin metabolism

1998 ◽  
Vol 13 (2) ◽  
pp. 249-257 ◽  
Author(s):  
Klaus Vo ◽  
Schwartzenberg ◽  
Sven Kruse ◽  
Ralf Reski ◽  
Barbara Moffatt ◽  
...  
Keyword(s):  
Adenosine Kinase ◽  
Cytokinin Metabolism

scholarly journals Epigenetic Control of Effector Gene Expression in the Plant Pathogenic Fungus Leptosphaeria maculans

PLoS Genetics ◽  
2014 ◽  
Vol 10 (3) ◽  
pp. e1004227 ◽  
Author(s):  
Jessica L. Soyer ◽  
Mennat El Ghalid ◽  
Nicolas Glaser ◽  
Bénédicte Ollivier ◽  
Juliette Linglin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pathogenic Fungus ◽  
Leptosphaeria Maculans ◽  
Plant Pathogenic Fungus ◽  
Epigenetic Control ◽  
Effector Gene

scholarly journals Knockout of the HvCKX1 or HvCKX3 Gene in Barley (Hordeum vulgare L.) by RNA-Guided Cas9 Nuclease Affects the Regulation of Cytokinin Metabolism and Root Morphology

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 782 ◽  
Author(s):  
Gasparis ◽  
Przyborowski ◽  
Kała ◽  
Nadolska-Orczyk
Keyword(s):  
Grain Yield ◽  
Root Morphology ◽  
Genetic Manipulation ◽  
Root Hairs ◽  
Cytokinin Oxidase ◽  
Cytokinin Metabolism ◽  
Hordeum Vulgare L ◽  
Crop Species ◽  
Grain Yields ◽  
Mutant Lines

Barley is among four of the most important cereal crops with respect to global production. Increasing barley yields to desired levels can be achieved by the genetic manipulation of cytokinin content. Cytokinins are plant hormones that regulate many developmental processes and have a strong influence on grain yield. Cytokinin homeostasis is regulated by members of several multigene families. CKX genes encode the cytokinin oxidase/dehydrogenase enzyme, which catalyzes the irreversible degradation of cytokinin. Several recent studies have demonstrated that the RNAi-based silencing of CKX genes leads to increased grain yields in some crop species. To assess the possibility of increasing the grain yield of barley by knocking out CKX genes, we used an RNA-guided Cas9 system to generate ckx1 and ckx3 mutant lines with knockout mutations in the HvCKX1 and HvCKX3 genes, respectively. Homozygous, transgene-free mutant lines were subsequently selected and analyzed. A significant decrease in CKX enzyme activity was observed in the spikes of the ckx1 lines, while in the ckx3 lines, the activity remained at a similar level to that in the control plants. Despite these differences, no changes in grain yield were observed in either mutant line. In turn, differences in CKX activity in the roots between the ckx1 and ckx3 mutants were reflected via root morphology. The decreased CKX activity in the ckx1 lines corresponded to greater root length, increased surface area, and greater numbers of root hairs, while the increased CKX activity in the ckx3 mutants gave the opposite results. RNA-seq analysis of the spike and root transcriptomes revealed an altered regulation of genes controlling cytokinin metabolism and signaling, as well as other genes that are important during seed development, such as those that encode nutrient transporters. The observed changes suggest that the knockout of a single CKX gene in barley may be not sufficient for disrupting cytokinin homeostasis or increasing grain yields.

scholarly journals Structure-based insights into evolution of rhodopsins

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Dmitrii Zabelskii ◽  
Natalia Dmitrieva ◽  
Oleksandr Volkov ◽  
Vitaly Shevchenko ◽  
Kirill Kovalev ◽  
...  
Keyword(s):  
Pathogenic Fungus ◽  
Leptosphaeria Maculans ◽  
Direct Interaction ◽  
Striking Similarity ◽  
Proton Pumps ◽  
Evolution Of Life ◽  
High Resolution Structure ◽  
Domains Of Life ◽  
Life On Earth ◽  
Insight Into

AbstractRhodopsins, most of which are proton pumps generating transmembrane electrochemical proton gradients, span all three domains of life, are abundant in the biosphere, and could play a crucial role in the early evolution of life on earth. Whereas archaeal and bacterial proton pumps are among the best structurally characterized proteins, rhodopsins from unicellular eukaryotes have not been well characterized. To fill this gap in the current understanding of the proton pumps and to gain insight into the evolution of rhodopsins using a structure-based approach, we performed a structural and functional analysis of the light-driven proton pump LR (Mac) from the pathogenic fungus Leptosphaeria maculans. The first high-resolution structure of fungi rhodopsin and its functional properties reveal the striking similarity of its membrane part to archaeal but not to bacterial rhodopsins. We show that an unusually long N-terminal region stabilizes the protein through direct interaction with its extracellular loop (ECL2). We compare to our knowledge all available structures and sequences of outward light-driven proton pumps and show that eukaryotic and archaeal proton pumps, most likely, share a common ancestor.

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