Faculty Opinions recommendation of Transformation of the flax rust fungus, Melampsora lini: selection via silencing of an avirulence gene.

2013 ◽  
Author(s):  
Alexander Idnurm
Keyword(s):  
Rust Fungus ◽  
Avirulence Gene ◽  
Melampsora Lini

scholarly journals Genome analysis and avirulence gene cloning using a high-density RADseq linkage map of the flax rust fungus, Melampsora lini

BMC Genomics ◽  
2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Claire Anderson ◽  
Muhammad Adil Khan ◽  
Ann-Maree Catanzariti ◽  
Cameron A. Jack ◽  
Adnane Nemri ◽  
...  
Keyword(s):  
Gene Cloning ◽  
Linkage Map ◽  
Genome Analysis ◽  
Rust Fungus ◽  
High Density ◽  
Avirulence Gene ◽  
Melampsora Lini

Metabolism of glucose-14C, pyruvate-14C, and mannitol-14C by Melampsora lini. II. Conversion to soluble products

1968 ◽  
Vol 46 (4) ◽  
pp. 453-460 ◽  
Author(s):  
D. Mitchell ◽  
Michael Shaw
Keyword(s):  
Pentose Phosphate Pathway ◽  
Tricarboxylic Acid Cycle ◽  
Rust Fungus ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Pentose Phosphate ◽  
Soluble Carbohydrates ◽  
Melampsora Lini ◽  
Carbohydrate Fraction ◽  
The Tca Cycle

Mycelium of the flax rust fungus (Melampsora lini (Pers.) Lév.), grown on flax cotyledons in tissue culture, had a mean [Formula: see text]of 4.1 and a mean C6/C1 ratio of 0.14, measured after 4 hours in radioactive glucose. The C6/C1 ratio increased with time and also after treatment with 10−5 M 2,4-dinitrophenol. The relative labelling of the (80%) ethanol-soluble carbohydrates, and organic and amino acid fractions after incubation with glucose-1-, -2-, or -6-14C also indicated preferential release of C1 as 14CO2. Trehalose (unknown A) was tentatively identified in the carbohydrate fraction and was mildly radioactive after incubation of the mycelium with labelled glucose for 3 hours. The principal radioactive products of glucose in this fraction were two unknowns, B and C, which were tentatively identified as mannitol and arabitol. The labelling patterns were consistent with their formation from intermediates of the pentose phosphate pathway. The distribution of radioactivity derived from glucose in alanine, glutamate, and aspartate also indicated that hexose or triose units formed in the pentose phosphate pathway were converted to pyruvate, which either gave rise to alanine or was further oxidized in the tricarboxylic acid cycle. Incubation with pyruvate-1-, -2-, or -3-14C for 3 hours gave rise to 14CO2 and labelled alanine, glutamate, and aspartate in a manner consistent with the operation of the TCA cycle. Mannitol-1-6-14C was not metabolized to any appreciable extent in this period, but did give rise to 14CO2 and to several unidentified compounds in the carbohydrate fraction.

Metabolism of glucose-14C, pyruvate-14C, and mannitol-14C by Melampsora lini. I. Uptake

1968 ◽  
Vol 46 (4) ◽  
pp. 435-440 ◽  
Author(s):  
P. G. Williams ◽  
Michael Shaw
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Rust Fungus ◽  
Aerial Mycelium ◽  
Dry Weight ◽  
Significant Negative Correlation ◽  
Mean Value ◽  
Pentose Phosphate ◽  
Endogenous Respiration ◽  
Melampsora Lini ◽  
Pentose Phosphate Pathways

Aerial mycelium of the flax rust fungus (Melampsora lini (Pers.) Lév.) was grown on infected flax cotyledons in tissue culture. The endogenous respiration of detached mycelium varied from 1.5 to 4.8 μl/h per milligram dry weight, with a mean value of 2.6 ± 1.0. There was a significant negative correlation between respiration rate and percentage dry weight (r = −0.832; P < 0.025). The respiration of mycelium stored for longer than 10 h after excision was stimulated by the addition of glucose; such stimulation was not obtained consistently with freshly collected mycelium.The production of 14CO2 and the disappearance of radioactivity from the medium were measured at intervals during incubation of mycelium with glucose-1- and -6-14C, sodium pyruvate-1-, -2-, and -3-14C and mannitol-1-6-14C. Evidence was obtained that glucose is oxidized in the Embden–Meyerhof and pentose phosphate pathways and that pyruvate is oxidized via acetyl CoA and the tricarboxylic acid cycle. Rapid utilization of pyruvate- and mannitol-14C was preceded by a lag period of 4 to 9 h. The results are discussed in relation to the suitability of aerial mycelium for the study of rust metabolism.

A quantitative histological and ultrastructural analysis of interactions between the flax rust and near-isogenic host lines varying in their degree of incompatibility

1983 ◽  
Vol 61 (7) ◽  
pp. 1831-1850 ◽  
Author(s):  
Michael D. Coffey ◽  
Frances H. E. Allen
Keyword(s):  
Phosphotungstic Acid ◽  
Rust Fungus ◽  
Periodic Acid ◽  
Fungal Growth ◽  
Host Cells ◽  
Similar Proportion ◽  
Thin Sections ◽  
Melampsora Lini ◽  
Uninfected Host ◽  
Electron Lucent

Histological differences were evident in the leaves of eight near-isogenic lines of flax infected with the rust fungus Melampsora lini. Compared with the compatible L9 and M1 interactions, fungal growth was progressively more restricted in the moderately incompatible K and M4, incompatible M and P, and highly incompatible L and M3 interactions. This restriction took place in advance of appreciable necrosis of host cells in K, M4, M, and P. At 72 h the proportion of haustoria-containing cells which were necrotic was only 10–15% in K and M4. In M at 72 h necrosis was 80% or more at infection sites with small colonies but was negligible at sites with large colonies. In P, by contrast, a similar proportion of necrosis, 40% at 72 h, was present at all infection sites. However, in L and M3 host necrosis was much more rapid and the fungus was restricted to a few host cells. An early ultrastructural event was the appearance of extensive fibrillar deposits in the initially electron-lucent extrahaustorial matrices of both the incompatible M and P and moderately incompatible M4 and K interactions. A positive reaction with silver proteinate indicated that these matrical deposits contained carbohydrate, possibly a mucopolysaccharide or glycoprotein, but they were not extracted by either cellulase, pectinase, or chitinase. The extrahaustorial membrane, surrounding the haustoria in the compatible L9 and M1 interactions and the moderately incompatible K interaction was not stained by the periodic acid – phosphotungstic acid – chromic acid (PACP) procedure believed specific for the plasmalemma. In incompatible reactions clusters of electron-dense particles sometimes replaced starch in plastids of infected host cells. This event usually coincided with the appearance of extensive matrical deposits around fungal haustoria. At the same time particles were also found in plastids in uninfected host cells immediately adjacent to infection sites, particularly in the M and P interactions. These particles were extracted from thin sections by using pullulanase followed by α-amylase, indicating that they consisted of highly branched amylopectin.

Further observations on the growth of flax rust fungus in axenic culture

1984 ◽  
Vol 62 (10) ◽  
pp. 2175-2180 ◽  
Author(s):  
Rosalinda Boasson ◽  
Michael Shaw
Keyword(s):  
Heat Shock ◽  
Incubation Period ◽  
Rust Fungus ◽  
Axenic Culture ◽  
Subsequent Development ◽  
Stages Of Growth ◽  
Melampsora Lini ◽  
Tube Emergence ◽  
Initial Ph ◽  
Total Growth

Axenic cultures of flax rust (Melampsora lini (Ehrenb.) Lév.) grown from sterile uredospores on a defined liquid medium in 125-mL Erlenmeyer flasks exhibited an incubation period of 12 to 20 days followed by a period of rapid growth and sporulation. A heat shock (31–33 °C for 2–2.5 h) administered 3 h after seeding the medium did not induce the formation of infection structures, but doubled the number of vegetative colonies initiated and increased total growth per flask (protein/flask) in 4 weeks by 20-fold. The optimum timing of the heat shock corresponded closely with the maximum rate of germ tube emergence. Ambient CO2 was not essential for germination or perception of the heat shock, but was essential, during the first half of the incubation period, for the subsequent development of vegetative colonies. CO2 fixation occurred at all stages of growth from 1 day onward, 14CO2 being incorporated into ethanol-insoluble and ethanol-soluble fractions, including amino acids. Growth rate following the incubation period was not affected by the initial pH of the medium between 5.0 and 6.0, but the incubation period was shorter at pH 6.0.

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