Mahajabeen Padamsee

Manaaki Whenua - Landcare Research · Systematics Team

ABSTRACT Rust fungi are obligate plant pathogens, usually restricted to a single host species or genus, although some species such as myrtle rust (Austropuccinia psidii) and some cereal and grass rusts (Puccinia spp.) can infect many members of the families Myrtaceae and Poaceae, respectively. The rust life cycle can involve up to five spore stages...

Fungi play vital roles in ecosystems as endophytes, pathogens and saprobes. The current estimate of fungal diversity is highly uncertain, ranging from 1.5 to 12 million, but only around 150,000 species have been named and classified to date. Since the introduction of DNA based methods for species identification, the number of newly described taxa h...

Early diverging taxa of Ascomycota and Basidiomycota share similarities in subcellular characters of the spindle pole body (SPB), nuclear division, and septal pore apparatus, but our understanding of character evolution is incomplete because of the limited number of structural studies within the earliest diverging subphyla of Dikarya, Taphrinomycot...

Molecular phylogenies using 1-4 gene regions and information on ecology, morphology and pigment chemistry were used in a partial revision of the agaric family Hygro- phoraceae. The phylogenetically supported genera we recognize here in the Hygrophoraceae based on these and previous analyses are: Acantholichen, Ampulloclitocybe, Arrhenia, Cantharell...

Wallemia (Wallemiales, Wallemiomycetes) is a genus of xerophilic Fungi of uncertain phylogenetic position within Basidiomycota. Most commonly found as food contaminants, species of Wallemia have also been isolated from hypersaline environments. The ability to tolerate environments with reduced water activity is rare in Basidiomycota. We sequenced t...

Wallemia (Wallemiales, Wallemiomycetes) is a genus of xerophilic Fungi that is of uncertain phylogenetic position within the Basidiomycota. Most commonly found as food contaminants, species of Wallemia have also been isolated from hypersaline environments. The ability to tolerate low water environments is rare in the Basidiomycota and suggests seve...

Mycoheterotrophic plants are achlorophyllous plants that obtain carbon from their mycorrhizal fungi. They are usually considered to associate with fungi that are (1) specific of each mycoheterotrophic species and (2) mycorrhizal on surrounding green plants, which are the ultimate carbon source of the entire system. Here we review recent works revea...

Deletion of the acyltransferases responsible for triglyceride and steryl ester synthesis in Saccharomyces cerevisiae serves as a genetic model of diseases where lipid overload is a component. The yeast mutants lack detectable neutral lipids and cytoplasmic lipid droplets and are strikingly sensitive to unsaturated fatty acids. Expression of human d...

Ultrastructure of the cystidia of Psathyrella aff. nolitangere (Fr.) A.Pearson & Dennis and Psathyrellarhodospora Weaver & Smith (Agaricales) was examined primarily using freeze substitution, with the goal of evaluating whether these cells could provide phylogenetically informative characters with which to study morphological evolution. Within the...

Cystidia of Suillus americanus and S. granulatus (Boletales) were examined cytochemically and ultrastructurally with cells prepared by freeze substitution. We present the first study showing ultrastructural details and cytological functions of the cystidium to be conserved in two closely related species. The results are presented for inclusion in t...

As a part of a broader study to determine whether the subcellular structure of cystidia can provide synapomorphies for clades of Agaricomycetes, cystidia of Auriscalpium vulgare Gray and Russula emetica (Schaeff.) Pers. were examined ultrastructurally, after freeze substitution. Vesicles with tubular invaginations occurred in immature hymenial cyst...

Psathyrella is the archetypal little brown mushroom genus with few easily discernable characters causing it to be considered a "clean-up" genus for other small brown-spored saprotrophic species found worldwide. While molecular studies have demonstrated that mushroom genera based on homoplastic morphological characters are artificial, the degree of...

Ultrastructure of the septal pore apparatus and nuclear division of Auriscalpium vulgare (Russulales) was examined with freeze substitution and is presented for inclusion in the AFTOL Structural and Biochemical Database (http://aftol.umn.edu). Previously unreported septal characters for the Russulales (Agaricomycotina) were observed: Septa of the h...

Ultrastructure of the septal pore apparatus and nuclear division of Auriscalpium vulgare (Russulales) was examined with freeze substitution and is presented for inclusion in the AFTOL Structural and Biochemical Database (http://aftol.umn.edu). Previously unreported septal characters for the Russulales (Agaricomycotina) were observed: Septa of the h...

A major goal of the Assembling the Fungal Tree of Life project is to create a searchable database <http://aftol.umn.edu> of selected ultrastructural and biochemical characters from published and new data for use in phylogenetic and other analyses. While developing this database such issues as evaluating specimen fixation quality in published microg...

A major goal of the Assembling the Fungal Tree of Life project is to create a searchable database <http://aftol.umn.edu> of selected ultrastructural and biochemical characters from published and new data for use in phylogenetic and other analyses. While developing this database such issues as evaluating specimen fixation quality in published microg...

The esterification of alcohols such as sterols, diacylglycerols, and monoacylglycerols with fatty acids represents the formation of both storage and cytoprotective molecules. Conversely, the overproduction of these molecules is associated with several disease pathologies, including atherosclerosis and obesity. The human acyl-CoA:diacylglycerol acyl...

Based on an overview of progress in molecular systematics of the true fungi (Fungi/Eumycota) since 1990, little overlap was found among single-locus data matrices, which explains why no large-scale multilocus phylogenetic analysis had been undertaken to reveal deep relationships among fungi. As part of the project "Assembling the Fungal Tree of Lif...

A phylogeny of the Basidiomycota is presented drawing upon nucleotide and amino acid sequences of nuclear ribosomal RNA loci (18S and 25S) and protein-coding genes that include RPB1 and RPB2 (which encode the largest and second largest subunits of RNA polymerase II, respectively), elongation factor 1-alpha, and mitochondrial ATP6. Taxon sampling, g...

Lipid movement between organelles is a critical component of eukaryotic membrane homeostasis. Niemann Pick type C (NP-C) disease is a fatal neurodegenerative disorder typified by lysosomal accumulation of cholesterol and sphingolipids. Expression of yeast NP-C-related gene 1 (NCR1), the orthologue of the human NP-C gene 1 (NPC1) defective in the di...

We present an overview of progress in molecular systematics of Fungi since 1990, and demonstrate that overlap among data matrices has been very low. As a result, many of the currently available data cannot be used in multi-locus analyses to infer fungal relationships on a large scale. We report here the results of four Bayesian analyses with comple...

Diacylglycerol esterification provides an excellent target for the pharmacological reduction of triglyceride accumulation in several human disease states. We have usedSaccharomyces cerevisiae as a model system to study this critical component of triglyceride synthesis. Recent studies of an oleaginous fungus, Mortierella ramanniana, identified a new...

Thesis (M.S.)--University of Minnesota, 2001. Includes bibliographical references (leaves 69-74).