A Molecular Approach to Distinguish the Bean Rust and Siratro Rust Pathogens

1991 ◽  
Vol 39 (6) ◽  
pp. 527 ◽  
Author(s):  
KS Braithwaite ◽  
JM Manners ◽  
DJ Maclean ◽  
JAG Irwin
Keyword(s):  
Rust Fungus ◽  
Repeat Unit ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Rust Disease ◽  
Dna Repeat ◽  
Total Dna ◽  
Macroptilium Atropurpureum ◽  
Genomic Probes ◽  
Rust Pathogens

Rust disease on the tropical pasture legume Macroptilium atropurpureum (siratro) is caused by Uromyces appendiculatus var. crassitunicatus. This pathogen was believed to be closely related to the bean (Phaseolus vulgaris) rust pathogen Uromyces appendiculatus var. appendiculatus. The genetic relationship between these two fungi was investigated. Total DNA hybridisations indicated that little homology exists between the high copy genomic DNA of these two rust fungi. Random genomic probes cloned from the bean rust fungus detected extensive Polymorphisms between the two, with only one probe from 17 being monomorphic. The ribosomal DNA repeat unit was also distinguished by RFLPs. It was calculated from the RFLP data that the bean rust fungus and the siratro rust fungus share only 8-14% sequence homology. The results indicate that the two fungi, although morphologically very similar, are not closely related genetically.

scholarly journals Isolates of Uromyces appendiculatus with Specific Virulence to Landraces of Phaseolus vulgaris of Andean Origin

Plant Disease ◽  
1999 ◽  
Vol 83 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Craig M. Sandlin ◽  
James R. Steadman ◽  
Carlos M. Araya ◽  
Dermot P. Coyne
Keyword(s):  
Phaseolus Vulgaris ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Rust Fungus ◽  
Distinct Group ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Banding Patterns ◽  
Highly Virulent ◽  
Specific Virulence

Five isolates of the bean rust fungus Uromyces appendiculatus were shown to be specifically virulent on bean genotypes of Andean origin. This specificity was demonstrated by the virulence of five pairs of isolates on a differential set of 30 Phaseolus vulgaris landraces. Each isolate pair was from a different country in the Americas and consisted of one Andean-specific isolate and one nonspecific isolate. Of the differential P. vulgaris landraces, 15 were of Middle American origin and 15 were of Andean origin. The Andean-specific rust isolates were highly virulent on Andean landraces but not on landraces of Middle American origin. Rust isolates with virulence to Middle American landraces were also generally virulent on Andean material; no truly Middle American-specific isolates were found. Random amplified polymorphic DNA (RAPD) analysis of the rust isolates also distinguished the two groups. Four of the Andean-specific rust isolates formed a distinct group compared to four of the nonspecific isolates. Two of the isolates, one from each of the two virulence groups, had intermediate RAPD banding patterns, suggesting that plasmagomy but not karyogamy occurred between isolates of the two groups.

scholarly journals Virulence and isozyme diversity of sexual versus asexual collections of Uromyces appendiculatus (bean rust fungus)

Heredity ◽  
1995 ◽  
Vol 75 (3) ◽  
pp. 234-242 ◽  
Author(s):  
James V Groth ◽  
John W McCain ◽  
Alan P Roelfs
Keyword(s):  
Rust Fungus ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Isozyme Diversity

Uromyces appendiculatus var. crassitunicatus, var. nov. from Macroptilium atropurpureum

1988 ◽  
Vol 1 (4) ◽  
pp. 363
Author(s):  
JAG Irwin
Keyword(s):  
Rust Fungi ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Entire Surface ◽  
New Variety ◽  
Morphological Studies ◽  
Side Walls ◽  
Macroptilium Atropurpureum ◽  
Uromyces Vignae

Morphological studies on the rust fungi of Macroptilium, Phaseolus and Vigna show that three taxa can be distinguished. The Vigna rust, Uromyces vignae, is maintained as a species distinct from the bean rust, U. appendiculatus var. appendiculatus. A new variety, Uromyces appendiculatus (Pers.) Unger var. crassitunicatus J. Irwin, is described from Macroptilium atropurpureum. It differs from var. appendiculatus in having urediniospores with thicker side walls and more closely spaced echinulae. The teliospores are similar to those of var. appendiculatus, except that the side walls are thicker; the side walls are darker, with lineal rows of warts over the entire surface, and a conspicuous channel in the base; the hyaline apical thickening is thinner; and pedicels are more broadly attached.

scholarly journals Vegetative development of Uromyces appendiculatus var. appendiculatus in Phaseolus vulgaris

1984 ◽  
Vol 62 (10) ◽  
pp. 2003-2010 ◽  
Author(s):  
R. E. Gold ◽  
K. Mendgen
Keyword(s):  
Phaseolus Vulgaris ◽  
Host Cell ◽  
Rust Fungus ◽  
Mesophyll Cell ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Palisade Parenchyma ◽  
Vegetative Development ◽  
Electron Microscopic ◽  
Mesophyll Cells

The morphology of intercellular and intracellular hyphae derived from basidiospores of Uromyces appendiculatus var. appendiculatus is described. Light and electron microscopic observations of the bean rust fungus were made on susceptible leaves of Phaseolus vulgaris from 3 to 10 days after inoculation. Following egress from invaded epidermal and palisade parenchyma cells, the fungus grew rapidly and developed extensive intercellular mycelium. An amorphous to fibrillar extracellular matrix was deposited between fungal and host cell walls. Intercellular hyphae grew closely appressed to the mesophyll cells and penetrated them to form intracellular hyphae from either a terminal or nonterminal mother cell. Intracellular hyphae were fingerlike, sometimes septate, and generally remained terminal in the invaded mesophyll cell. Occasionally the fungus exited the cell to become an intercellular hypha or an intracellular hypha in an adjacent host cell. The plant rarely exhibited a resistantlike reaction at sites of penetration into mesophyll cells.

scholarly journals Melampsora larici-populina Transcript Profiling During Germination and Timecourse Infection of Poplar Leaves Reveals Dynamic Expression Patterns Associated with Virulence and Biotrophy

2011 ◽  
Vol 24 (7) ◽  
pp. 808-818 ◽  
Author(s):  
Sébastien Duplessis ◽  
Stéphane Hacquard ◽  
Christine Delaruelle ◽  
Emilie Tisserant ◽  
Pascal Frey ◽  
...  
Keyword(s):  
Rust Fungus ◽  
Expression Patterns ◽  
Infection Process ◽  
Plant Colonization ◽  
In Planta ◽  
Rust Disease ◽  
Dynamic Expression ◽  
Transcript Profiles ◽  
Rust Pathogens ◽  
Poplar Leaves

Melampsora larici-populina is responsible for poplar leaf rust disease and causes severe epidemics in poplar plantations in Europe. The poplar rust genome has been recently sequenced and, in order to find the genetic determinants associated with its biotrophic lifestyle, we generated a whole-genome custom oligoarray and analyzed transcript profiles of M. larici-populina during the infection timecourse in poplar leaves. Different stages were investigated during the asexual development of the rust fungus, including resting and germinating urediniospores and seven in planta stages in the telial host. In total, 76% of the transcripts were detected during leaf infection as well as in urediniospores, whereas 20% were only detected in planta, including several transporters and many small secreted proteins (SSP). We focused our analysis on gene categories known to be related to plant colonization and biotrophic growth in rust pathogens, such as SSP, carbohydrate active enzymes (CAZymes), transporters, lipases, and proteases. Distinct sets of SSP transcripts were expressed all along the infection process, suggesting highly dynamic expression of candidate rust effectors. In contrast, transcripts encoding transporters and proteases were mostly expressed after 48 h postinoculation, when numerous haustoria are already formed in the leaf mesophyll until uredinia formation, supporting their role in nutrient acquisition during biotrophic growth. Finally, CAZymes and lipase transcripts were predominantly expressed at late stages of infection, highlighting their importance during sporulation.

DNA Markers Reveal Hybrids Between Two Diverse Background Genotypes in Australian Collections of the Bean Rust Fungus Uromyces appendiculatus

1994 ◽  
Vol 42 (3) ◽  
pp. 255 ◽  
Author(s):  
KS Braithwaite ◽  
JM Manners ◽  
JAG Irwin ◽  
DJ Maclean
Keyword(s):  
Comprehensive Evaluation ◽  
Genetic Recombination ◽  
Random Amplified Polymorphic Dna ◽  
Rust Fungus ◽  
Uromyces Appendiculatus ◽  
Rflp Markers ◽  
Clear Correlation ◽  
Bean Rust ◽  
Arbitrary Primers ◽  
Polymorphic Bands

Two classes of molecular markers, RFLPs (restriction fragment length polymorphisms) and RAPDs (random amplified polymorphic DNA) were used to assess genetic diversity among Australian bean rust isolates (Uromyces appendiculatus (Pers.) Unger var. appendiculatus) collected from diverse geographic locations spanning the period 1973-1990. Initially we screened 22 isolates using WLPs from five DNA probes. This was followed by analysis of a subset of 12 of these isolates using RFLPs from 10 cDNA probes and RAPDs from 10 arbitrary primers for a comprehensive evaluation of background genotype. Polymorphic bands revealed the existence of two divergent clusters of isolates, representing genotypes designated A and B. The RFLP markers showed 30% band dissimilarity between A and B, and RAPDs 16% dissimilarity. Isolates in a third cluster (genotype AB) exhibited most of the polymorphic bands present in A and B, but no unique polymorphic bands of their own, indicating that they had most probably arisen from recent hybridisation between isolates of genotype A and B. The subset of 12 isolates included 10 race phenotypes, but no clear correlation between background genotype (as assessed by RFLP and RAPD markers) and race phenotype was evident. We suggest that Australian races of bean rust have most probably evolved by a combination of mutation to virulence from common A and B background genotypes, and genetic recombination.

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