Nanoscale enrichment of the cytosolic enzyme trichodiene synthase near reorganized endoplasmic reticulum in Fusarium graminearum

Trichothecene-producing and -nonproducing Fusarium graminearum strains were tested for their ability to cause Gibberella ear rot in field trials at two locations—Ottawa, Ontario, and Peoria, Illinois—in 1996. Maize ears were inoculated with wild-type or transgenic F. graminearum strains in which the trichothecene biosynthetic pathway had been disabled by the specific disruption of the trichodiene synthase gene and with a derivative revertant strain in which trichothecene production had been restored through recombination. A silk channel inoculation method was employed at both locations. In addition, a kernel puncture inoculation method was used at the Ontario location. Harvested maize ears were analyzed for visual disease severity, grain yield, deoxynivalenol (DON) concentration, and fungal biomass by quantitative polymerase chain reaction (PCR) and/or ergosterol quantitation. There was a significant correlation (r= 0.86) between data obtained from the two different methods of quantifying fungal biomass. The trichothecene-nonproducing strains were still pathogenic but appeared less virulent on maize than the trichothecene-producing progenitor and revertant strains, as assayed by most parameters. This suggests that the trichothecenes may act as virulence factors to enhance the spread of F. graminearum on maize.

Download Full-text

Real-time PCR Quantification and Mycotoxin Production of Fusarium graminearum in Wheat Inoculated with Isolates Collected from Potato, Sugar Beet, and Wheat

Phytopathology ◽

10.1094/phyto-97-7-0835 ◽

2007 ◽

Vol 97 (7) ◽

pp. 835-841 ◽

Cited By ~ 54

Author(s):

Rishi R. Burlakoti ◽

Rolando Estrada ◽

Viviana V. Rivera ◽

Anuradha Boddeda ◽

Gary A. Secor ◽

...

Keyword(s):

Sugar Beet ◽

Real Time ◽

Fusarium Graminearum ◽

Real Time Pcr ◽

The United States ◽

Taqman Probe ◽

Head Blight ◽

Dry Rot ◽

Trichodiene Synthase ◽

Intergenic Sequences

Fusarium graminearum causes Fusarium head blight (FHB) in small grains worldwide. Although primarily a pathogen of cereals, it also can infect noncereal crops such as potato and sugar beet in the United States. We used a real-time polymerase chain reaction (PCR) method based on intergenic sequences specific to the trichodiene synthase gene (Tri5) from F. graminearum. TaqMan probe and primers were designed and used to estimate DNA content of the pathogen (FgDNA) in the susceptible wheat cv. Grandin after inoculation with the 21 isolates of F. graminearum collected from potato, sugar beet, and wheat. The presence of nine mycotoxins was analyzed in the inoculated wheat heads by gas chromatography and mass spectrometry. All isolates contained the Tri5 gene and were virulent to cv. Grandin. Isolates of F. graminearum differed significantly in virulence (expressed as disease severity), FgDNA content, and mycotoxin accumulation. Potato isolates showed greater variability in producing different mycotoxins than sugar beet and wheat isolates. Correlation analysis showed a significant (P < 0.001) positive relationship between FgDNA content and FHB severity or deoxynivalenol (DON) production. Moreover, a significant (P < 0.001) positive correlation between FHB severity and DON content was observed. Our findings revealed that F. graminearum causing potato dry rot and sugar beet decay could be potential sources of inoculum for FHB epidemics in wheat. Real-time PCR assay provides sensitive and accurate quantification of F. graminearum in wheat and can be useful for monitoring the colonization of wheat grains by F. graminearum in controlled environments, and evaluating wheat germplasms for resistance to FHB.

Download Full-text

A Genetic Map of Gibberella zeae (Fusarium graminearum)

Genetics ◽

10.1093/genetics/160.4.1451 ◽

2002 ◽

Vol 160 (4) ◽

pp. 1451-1460

Author(s):

J E Jurgenson ◽

R L Bowden ◽

K A Zeller ◽

J F Leslie ◽

N J Alexander ◽

...

Keyword(s):

Linkage Map ◽

Fusarium Graminearum ◽

Gibberella Zeae ◽

Linkage Groups ◽

Genetic Studies ◽

Genomic Libraries ◽

Trichodiene Synthase ◽

Nit Mutants ◽

Length Polymorphisms ◽

Amplified Fragment Length Polymorphisms

Abstract We constructed a genetic linkage map of Gibberella zeae (Fusarium graminearum) by crossing complementary nitrate-nonutilizing (nit) mutants of G. zeae strains R-5470 (from Japan) and Z-3639 (from Kansas). We selected 99 nitrate-utilizing (recombinant) progeny and analyzed them for amplified fragment length polymorphisms (AFLPs). We used 34 pairs of two-base selective AFLP primers and identified 1048 polymorphic markers that mapped to 468 unique loci on nine linkage groups. The total map length is ~1300 cM with an average interval of 2.8 map units between loci. Three of the nine linkage groups contain regions in which there are high levels of segregation distortion. Selection for the nitrate-utilizing recombinant progeny can explain two of the three skewed regions. Two linkage groups have recombination patterns that are consistent with the presence of intercalary inversions. Loci governing trichothecene toxin amount and type (deoxynivalenol or nivalenol) map on linkage groups IV and I, respectively. The locus governing the type of trichothecene produced (nivalenol or deoxynivalenol) cosegregated with the TRI5 gene (which encodes trichodiene synthase) and probably maps in the trichothecene gene cluster. This linkage map will be useful in population genetic studies, in map-based cloning, for QTL (quantitative trait loci) analysis, for ordering genomic libraries, and for genomic comparisons of related species.

Download Full-text

Developing Kernel and Rachis Node Induce the Trichothecene Pathway of Fusarium graminearum During Wheat Head Infection

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-22-8-0899 ◽

2009 ◽

Vol 22 (8) ◽

pp. 899-908 ◽

Cited By ~ 66

Author(s):

Peter Ilgen ◽

Birgit Hadeler ◽

Frank J. Maier ◽

Wilhelm Schäfer

Keyword(s):

Fusarium Graminearum ◽

Green Fluorescence Protein ◽

Head Blight ◽

Plant Infection ◽

Trichodiene Synthase ◽

Gene Coding ◽

In The Wild ◽

Glycerol 3 Phosphate Dehydrogenase ◽

Dsred Gene ◽

Rachis Node

The fungal pathogen Fusarium graminearum is the most common agent of Fusarium head blight (FHB) in small grain cereals and cob rot of maize. The threat posed by this fungus is due to a decrease in yield and, additionally, mycotoxin contamination of the harvested cereals. Among the mycotoxins, trichothecenes influence virulence of F. graminearum in a highly complex manner that is strongly host- as well as chemotype-specific. The factors inducing mycotoxin production during plant infection are still unknown. To evaluate the induction of the trichothecene pathway, the green fluorescence protein (GFP) gene was fused to the promoter of the TRI5 gene coding for the trichodiene synthase and integrated into the genome by homologous integration. The resulting mutant contains a fully functional TRI5 gene ensuring virulence on wheat and exhibits GFP driven by the endogenous TRI5 promoter. We are now able to monitor the induction of trichothecenes under real-time conditions. To localize the fungus in the plant tissue, the dsRed gene was integrated under constitutive control of the glycerol-3-phosphate dehydrogenase (gpdA) promoter. We are now able to show that, first, induction of GFP as well as trichothecene production in the reporter strain reflects TRI5 induction and trichothecene production in the wild type; second, expression of TRI5 is inducible during growth in culture; and, third, trichothecene production is not uniformly induced during the onset of infection but is tissue specific during fungal infection of wheat.

Download Full-text

Expression of the Fusarium graminearum terpenome and involvement of the endoplasmic reticulum-derived toxisome

Fungal Genetics and Biology ◽

10.1016/j.fgb.2019.01.006 ◽

2019 ◽

Vol 124 ◽

pp. 78-87 ◽

Cited By ~ 8

Author(s):

Christopher M. Flynn ◽

Karen Broz ◽

Wilfried Jonkers ◽

Claudia Schmidt-Dannert ◽

H. Corby Kistler

Keyword(s):

Endoplasmic Reticulum ◽

Fusarium Graminearum

Download Full-text

In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050676 ◽

1974 ◽

Vol 32 ◽

pp. 132-133

Author(s):

John J. Wolosewick ◽

John H. D. Bryan

Keyword(s):

Endoplasmic Reticulum ◽

Smooth Endoplasmic Reticulum ◽

Nuclear Ring ◽

Rough Er ◽

Distal Direction ◽

In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

Download Full-text

Ultrastructure of the Parotid Gland of the Nine-Banded Armadillo

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080626 ◽

1977 ◽

Vol 35 ◽

pp. 640-641

Author(s):

J. R. Ruby

Keyword(s):

Endoplasmic Reticulum ◽

Parotid Gland ◽

Periodic Acid ◽

Acinar Cells ◽

Duct System ◽

Parotid Glands ◽

Dasypus Novemcinctus ◽

Anterior Portion ◽

Periodic Acid Schiff ◽

Thin Sections

Parotid glands were obtained from five adult (four male and one female) armadillos (Dasypus novemcinctus) which were perfusion-fixed. The glands were located in a position similar to that of most mammals. They extended interiorly to the anterior portion of the submandibular gland.In the light microscope, it was noted that the acini were relatively small and stained strongly positive with the periodic acid-Schiff (PAS) and alcian blue techniques, confirming the earlier results of Shackleford (1). Based on these qualities and other structural criteria, these cells have been classified as seromucous (2). The duct system was well developed. There were numerous intercalated ducts and intralobular striated ducts. The striated duct cells contained large amounts of PAS-positive substance.Thin sections revealed that the acinar cells were pyramidal in shape and contained a basally placed, slightly flattened nucleus (Fig. 1). The rough endoplasmic reticulum was also at the base of the cell.

Download Full-text

Organisation in the Structure of the Cytoplasmic Ground Substance

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070357 ◽

1978 ◽

Vol 36 (3) ◽

pp. 627-639

Author(s):

K.R. Porter

Keyword(s):

Endoplasmic Reticulum ◽

Golgi Complex ◽

Random Distribution ◽

Ground Substance ◽

The Matrix ◽

Cell Processes ◽

Cytoplasmic Ground Substance

Most types of cells are known from their structure and overall form to possess a characteristic organization. In some instances this is evident in the non-random disposition of organelles and such system subunits as cisternae of the endoplasmic reticulum or the Golgi complex. In others it appears in the distribution and orientation of cytoplasmic fibrils. And in yet others the organization finds expression in the non-random distribution and orientation of microtubules, especially as found in highly anisometric cells and cell processes. The impression is unavoidable that in none of these cases is the organization achieved without the involvement of the cytoplasmic ground substance (CGS) or matrix. This impression is based on the fact that a matrix is present and that in all instances these formed structures, whether membranelimited or filamentous, are suspended in it. In some well-known instances, as in arrays of microtubules which make up axonemes and axostyles, the matrix resolves itself into bridges (and spokes) between the microtubules, bridges which are in some cases very regularly disposed and uniform in size (Mcintosh, 1973; Bloodgood and Miller, 1974; Warner and Satir, 1974).

Download Full-text

Ultrastructural Changes Associated with Alcoholic Hyalin in Hepatocytes and Biliary Epithelial Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066929 ◽

1971 ◽

Vol 29 ◽

pp. 572-573

Author(s):

Odell T. Minick ◽

Hidejiro Yokoo ◽

Fawzia Batti

Keyword(s):

Endoplasmic Reticulum ◽

Epithelial Cells ◽

Liver Biopsy ◽

Alcoholic Hepatitis ◽

Ultrastructural Changes ◽

Main Mass ◽

Biliary Epithelial Cells ◽

Biopsy Specimens ◽

Alcoholic Hyalin

To learn more of the nature and origin of alcoholic hyalin (AH), 15 liver biopsy specimens from patients with alcoholic hepatitis were studied in detail.AH was found not only in hepatocytes but also in ductular cells (Figs. 1 and 2), although in the latter location only rarely. The bulk of AH consisted of a randomly oriented network of closely packed filaments measuring about 150 Å in width. Bundles of filaments smaller in diameter (40-90 Å) were observed along the periphery of the main mass (Fig. 1), often surrounding it in a rim-like fashion. Fine filaments were also found close to the nucleus in both hepatocytes and biliary epithelial cells, the latter even though characteristic AH was not present (Figs. 3 and 4). Dispersed among the larger filaments were glycogen, RNA particles and profiles of endoplasmic reticulum. Dilated cisternae of endoplasmic reticulum were often conspicuous around the periphery of the AH mass. A limiting membrane was not observed.

Download Full-text