Mahajabeen Padamsee

Research interests

I am the programme leader of Beyond Myrtle Rust: towards Ecosystem Resilience, which is a five-year collaborative research programme into the behaviour, ecology and impacts of the disease in New Zealand. The programme will run to 2023 and involves  researchers and iwi from across Aotearoa. Beyond myrtle rust has four interlinking research areas: pathogen dynamics; ecosystem impacts; novel mitigation techniques; kaitiakitanga & Māori-led solutions. Within the programme I co-lead the research area that investigates the broad-scale impacts of Austropuccinia psidii on ecosystem functions. Once A. psidii establishes at a site, it will likely have impacts beyond host plant disease and death. For example, other microorganisms (e.g. bacteria and fungi) are likely to be impacted. Some microorganisms may reduce in abundance while others may increase, and this in turn can have impacts on plant health. It is important to understand whether plants with certain features (traits), such as large vs small leaves, are likely to be impacted differently. Combined, changes in plant features and the microbial community could lead to changes in ecosystem functions, such as water fluxes into and out of the ecosystem, carbon storage in soils, and nutrient movements through landscapes. We aim to develop a holistic understanding of the pathogen, host, and ecosystem changes, which will enable the best possible management approaches to be developed. This research project will use several study sites in the North Island.

I use multi-locus phylogenetics to study the evolution of New Zealand rust fungi (Pucciniales, Pucciniomycotina, Basidiomycota). The Pucciniales contain many economically important plant pathogens, which are intensively studied. However rusts that affect wild plants rarely receive the same attention, even though as obligate biotrophs they can play a key role in influencing the evolution of their host plants. New Zealand has approximately 250 species of rust fungi of which half are believed to be endemic. The paucity of endemic species makes it a tractable system within which to study the biogeographic distributions of rusts, species delimitation, and host specializations. I use molecular and morphological data to clarify rust fungal species concepts.

I am investigating the possible impacts of an exotic pathogen on fungal community assemblages in kauri (Agathis australis, Araucariaceae) forests. Kauri dieback was first diagnosed in the 1970s but the causal agent, Phytophthora taxon Agathis, has only recently has been found. I am interested in how the fungal community will change with the spread of this disease and finally, the death of associated kauri trees. I am currently establishing baseline data, using pyrosequencing, of the fungal diversity and density in undisturbed forests. In addition, I am isolating cultures of fungi found in kauri leaf litter and vouchering fresh mushrooms that occur in the vicinity of the trees that I am sampling. I will then research the fungal communities associated with diseased and dead kauri to evaluate how they may be affected by this exotic pathogen.

I used molecular phylogenetic analyses as well as morphology to address generic limits of the little brown mushroom genus Psathyrella (Psathyrellaceae) and related groups for my doctoral thesis research. I explored the evolution of several morphological characters in this family such as gill auto-digestion, basidiospore characteristics, and cystidial (modified sterile gill cells) features (Padamsee et al. 2008. Mol. Phylogenet. Evol.). Using transmission electron microscopy I studied cystidia of two closely related Psathyrella species (Padamsee et al. 2008. Botany). My study of Psathyrellaceae continues with a closer look at Psathyrella in New Zealand.

Publications

Padamsee, M., Arun Kumar, T.K., Riley, R., Binder, M., Boyd, A., Calvo, A.M., Furukawa, K., Hesse, C., Hohmann, S., James, T.Y., LaButti, K., Lapidus, A., Lindquist, E., Lucas, S., Miller, K., Shantappa, S., Grigoriev, I.V., Hibbett, D.S., McLaughlin, D.J., Spatafora, J.W., and Aime, M.C. The genome of the xerotolerant mold Wallemia sebi reveals adaptations to osmotic stress and suggests cryptic sexual reproduction. Fungal Genetics and Biology 49(3): 217-226.

Selosse, M.-A., Martos, F., Perry, B.A., Padamsee, M., and Pailler, T. 2010. New saprotrophic fungal symbionts in tropical achlorophyllous orchids: finding treasures among the ‘molecular leftovers’? Plant Signaling & Behavior. 5: 349-53.

Garbarino, J., Padamsee, M., Wilcox, L., Oelkers, P.M., D’Ambrosio, D., Ramsey, N., Jabado, O., Turkish, A.R., and Sturley, S.L. Sterol and Diacylglycerol Acyltransferase deficiency leads to unsaturated fatty acid mediated cell death. 2009. Journal of Biological Chemistry. 284: 30994-1005.

Padamsee, M., Matheny, P.B., Dentinger, B.T.M., and McLaughlin, D.J. 2008. The mushroom family Psathyrellaceae: evidence for large-scale polyphyly of the genus Psathyrella. Molecular Phylogenetics and Evolution 46: 415-429.

Padamsee, M., Celio, G.J., and McLaughlin, D.J. 2008. Using phylogeny and ultrastructure to study cystidia of two Psathyrella species: reciprocal illumination. Botany (formerly Canadian Journal of Botany) 86: 1334-1342.

McLaughlin, D.J., Celio, G.J., Padamsee, M., and Dentinger, B.T.M. Cystidial structure in two genera of the Russulales. 2008. Botany 86: 545-550.

Jenkinson, T.S., Celio, G.J., Padamsee, M., Dentinger, B.T.M., Myers, M.L., and McLaughlin, D.J. 2008. Conservation of cytoplasmic organization in the cystidia of Suillus species. Mycologia 100: 539-547.

Celio, G.J., Padamsee, M., Dentinger, B.T.M., Jenkinson, T.S., McLaughlin, E.G., and McLaughlin, D.J. 2007. Septal pore apparatus and nuclear division of Auriscalpium vulgare. Mycologia 99: 644-654.

Celio, G.J., Padamsee, M., Dentinger, B.T.M., Bauer, R., and McLaughlin, D.J. 2006. Assembling the Fungal Tree of Life: Constructing the structural and biochemical database. Mycologia 98:  850-859.

Turkish, A.R., Henneberry, A.L., Cromley, D., Padamsee, M., Oelkers, P., Bazzi, H., Christiano, A.M., Billheimer, J.T., and Sturley, S.L. 2005. Identification of two novel human acyl-CoA wax alcohol acyltransferases: members of the diacylglycerol acyltransferase 2 (DGAT2) gene superfamily. Journal of Biological Chemistry 280: 14755-14764.

Lutzoni, F., Kauff, F., C.J. Cox, C.J., McLaughlin, D.J., Celio, G., Dentinger, B.T., Padamsee, M., Hibbett, D., James, T.Y., Baloch, E.,  Grube, M., Reeb, V., Hofstetter, V., Schoch, C., Arnold, A.E., Miadlikowska, J., Spatafora, J.,  Johnson, D., Hambleton, S., Crockett, M., Shoemaker, R., Sung, G.-H., Lucking, R., Lumbsch, T., O’Donnell, K., Binder, M., Diederich, P., Ertz, D., Gueidan, C., Hall, B., Hansen, K., Harris, R.C., Hosaka, K., Lim, Y.-W., Liu, Y., Matheny, P.B., Nishida, H., Pfister, D., Rogers, J., Rossman, A., Schmitt, I., Sipman, H., Stone, J., Sugiyama, J., Yahr, R., and Vilgalys, R.  2004.  Where are we in assembling the fungal tree of life, classifying the fungi, and understanding the evolution of their subcellular traits. American Journal of Botany. 91: 1446-1480.

Krishnamurthy, M., Higaki, K., Tinkelenberg, A.H., Balderes, D.A., Almanzar-Paramio, D., Wilcox, L.J., Erdeniz, N., Redican, F., Padamsee, M., Liu, Y., Khan, S., Alcantara, F., Carstea, E.D., Morris, J.A., and Sturley, S.L. 2004. Mutagenesis of the putative sterol-sensing domain of yeast Niemann Pick C–related protein reveals a primordial role in subcellular sphingolipid distribution. Journal of Cell Biology 164: 547-556.

Oelkers, P., Cromley, D., Padamsee, M., Billheimer, J.T., and Sturley, S.L. 2002. The DGA1 gene determines a second triglyceride synthetic pathway in yeast. Journal of Biological Chemistry 277: 8877-8881.

Qualifications

Minnesota
PhD Plant Biological Science
2008

Publications