CoPIs: Adam J. Bogdanove, Julie A. Dickerson, Daniel S. Nettleton, and Adah Leshem-Ackerman (Iowa State University)
Collaborator: Pietro Spanu [Imperial College (UK)]
Plant diseases are among the greatest detriments to crop production worldwide. The plant immune system plays a crucial role in preventing infection by responding to pathogen-associated molecular patterns (PAMPs) and effector proteins delivered by the pathogen. This project focuses on the well-characterized barley-powdery mildew pathosystem to address fundamental questions in susceptibility and host resistance.
The project will build upon the recent discovery of a new monocot-specific family of cysteine-rich peptides, designated blufensins. Blufensin1 (Bln1) negatively regulates plant defense during fungal infection. BLN1 is predicted to be secreted, and contains both structural and sequence similarities to knottins, small disulfide-rich proteins characterized by a unique "disulfide through disulfide knot." The project team will perform comparative analysis of host (barley) versus nonhost (maize and rice) interactions with powdery mildew that define the interactome of cereals with this important fungal pathogen. Plants silenced for Bln1 will be interrogated by Barley1 GeneChip transcript profiling to identify significant new genes in the regulation of host innate immunity. Complementary investigations will be carried out with international collaborators that lead the powdery mildew genome sequence consortium to isolate powdery mildew effectors, which will then be used to identify important plant targets that promote or suppress defense. For this, the project will employ a new Xanthomonas type III secretion delivery vector to determine function in plant cells. Characterization of effectors will be carried out in all three cereals to identify and compare plant genes that govern host and non-host interactions. High-throughput reverse genetic tools will be utilized to functionally characterize genes identified via the Bln1- and powdery mildew effector-based approaches. Data will be integrated into PLEXdb (http://plexdb.org/), the unified gene expression resource for plants and plant pathogens, for genetic and regulatory network analysis.
Broader impacts will be achieved by integrating into the project training and mentoring for undergraduate and graduate students, postdocs, and NSF/NIH CSBSI summer interns in Bioinformatics. International research exchanges in powdery mildew effector prediction (UK) and functional analysis (USA) will enhance the experiences of graduate students and postdocs. In addition, underrepresented and underserved students in secondary science education will be engaged by partnering with the Des Moines School District to implement a biology classroom module on Gene Expression and Segregation Analysis in agriculture and human health. Public access to all project data will be fostered through the PLEXdb on-line relational database for gene expression for plants and plant pathogens as well as NCBI-GEO (www.ncbi.nlm.nih.gov/geo/). Thus, this project will promote research, education, and dissemination of results to a broad audience, while developing a new generation of agricultural scientists.
