Mary Wildermuth, Professor

Closed (1) Salicylic acid biosynthesis and regulation in Arabidopsis

Closed. This professor is continuing with Fall 2018 apprentices on this project; no new apprentices needed for Spring 2019.

Salicylic acid (SA, 2-hydroxybenzoate) accumulates in Arabidopsis leaves in response to pathogen infection and acts as a signaling molecule to induce plant defensive responses. We propose that conjugation of SA to the amino acid Aspartate changes it to an inactive form of the hormone that is then catabolized. In this way, the active concentration of the hormone SA can be tightly regulated. We have identified mutants and candidate genes that impact this process and seek to further characterize their function in the regulation of the plant immune response.

Perform a variety of assays to assess the role of identified mutants and candidate genes to assess their function in SA metabolism and plant immunity. Includes planting and caring for plants, performing disease assays, extracting SA metabolites for analysis, and quantitative gene expression analysis.

Day-to-day supervisor for this project: Rebecca Mackelprang, Graduate Student

Qualifications: Role: The undergraduate will work directly with a graduate student and the PI to design and implement experiments relevant to the above goals. Methodologies utilized will likely include RNA isolation and polymerase chain reaction (PCR), plant pathology assays, and small molecule extraction and HPLC analysis. Qualifications: Introductory Biology, Chemistry, Biochemistry (preferred), Organic Chemistry (preferred), Genetics and Plant Biology major preferred. 12-15 hrs/week preferred.

Weekly Hours: 12 or more hours

Closed (2) Elucidation of host plant and powdery mildew factors controlling powdery mildew growth on Arabidopsis

Applications for Spring 2019 are now closed for this project.

Powdery mildew is an obligate biotrophic fungus that infects a broad variety of plants including plants of agronomic (e.g. grapevine) and ornamental (e.g. roses) import. It has lost many essential metabolic pathways and relies on the plant for these compounds. We are interested in figuring out the plant metabolites required by the powdery mildew at each phase of its infection process as well as mechanisms by which the powdery mildew uptakes and alters plant metabolism to provide it with what it needs.

We also discovered that host nuclear DNA is amplified in the plant cells underlying the powdery mildew-infected mesophyll site. This process is called endoreduplication and is an alternate cell cycle in which DNA is replicated but mitosis does not occur, resulting in a doubling of the DNA content. Little is known about the regulators of this process. We are interested in elucidating regulators and function of powdery mildew-induced endoreduplication in host plants.

Project goals include i) examination of plant mutants in putative host genes of importance to key powdery mildew-acquired metabolites and/or cell cycle control and ii) silencing of plant and fungal targets to assess their impact on fungal growth, metabolite acquisition, and powdery mildew-induced endoreduplication.

Role: The undergraduate will work directly with a senior graduate student or postdoc and the PI to design and implement experiments relevant to the above goals. Methodologies utilized may include powdery mildew infections and quantitative disease scoring, cloning, transient expression assays, gene silencing, confocal microscopy, transcriptional profiling, and/or metabolite analyses. Genetic approaches are used to assess whether a given plant gene of interest contributes to disease resistance/susceptibility, metabolite acquisition by the fungus and/or endoreduplication. Transcriptional profiling and biochemical analyses may also help elucidate the function of a given gene of interest. Cloning and microscopy is used to determine localization of powdery mildew secreted proteins (effectors) in planta and interactions with host proteins. Undergraduates will also plant and care for plants used in their studies.

Day-to-day supervisor for this project: Amanda McRae, Jyoti Taneja, Graduate Student

Qualifications: Qualifications: Introductory Biology, Chemistry, Exposure to Molecular Biology desired but not required. Would like a student that can continue with this research for the full academic year. There will also be a possibility of summer funding. 12-15 hrs/week preferred.

Weekly Hours: 12 or more hours