CAREER: Regulatory Mechanisms of Pathogen-Mediated Cellular Stress Signaling in Arabidopsis: Taking Plant Molecular Biology to the Urban Garden

University Of Alabama At Birmingham, Birmingham AL

Investigators

Abstract

NON-TECHNICAL ABSTRACT: This project will establish an innovative and coherent platform to significantly enhance our understanding of pathogen-mediated endoplasmic reticulum (ER) stress in plants, train next-generation minority scientists, and engage an urban community in citizen science. The research scope of the project addresses a unique connection between the cellular stress and accumulation of unfolded proteins, and the plant immune system. Upon pathogen attack, plant cells increase production of new peptides, which consequently puts a burden on the protein folding machinery in the ER and causes cellular stress. Through this project, the investigators will learn about the molecular mechanisms underlying the efficient alleviation of this stress response in Arabidopsis. The insights gained from this research will impact the agricultural sciences by elucidating mechanisms to develop crop plants with the capacity to function under increased cellular stress - a necessity for a more sustainable future. Situated in Birmingham, AL, a city that has one of the most diverse and impoverished populations nationwide (74% African American, 25% below the poverty line), the investigators are in a unique position to foster plant biology-related education through outreach programs for underrepresented and socioeconomically underprivileged minorities. The investigators will implement an integrative service- and discovery-based learning outreach platform "OUTPACE" (OUTreach plant PAthology Clinic & Education) that is directed towards undergraduate students and citizen scientists: low-income urban gardening families of the local Community Gardens. OUTPACE will enable the students to acquire laboratory- and field-based knowledge of plant immunity and assist community growers in diagnosing plant diseases. These efforts are well aligned with current regional initiatives to enhance civic engagement and sustainable living, and combat urban malnutrition and hunger. TECHNICAL ABSTRACT: Inositol-Requiring Enzyme 1 (IRE1) is a highly conserved eukaryotic endoplasmic reticulum (ER) stress sensor. While chronic ER stress is linked with metazoan immune disorders, the role of IRE1a in plant immunity remains elusive. Recently, the principal investigator established the first known connection between the IRE1a and its client mRNA for the bZIP60 transcription factor in Arabidopsis immune signaling. Based on these findings, the investigators will expand their research questions to other key areas of ER signaling in plant immunity and address the following objectives: 1) Understanding the molecular mechanisms of biotic stress-dependent IRE1a activation and deactivation under oscillating ER stress conditions; 2) Elucidating the regulatory mechanisms of IRE1a functions in cellular adaptation or pathogen-mediated cell death; 3) Deciphering the feedback mechanisms between IRE1a and the salicylic acid receptor NPR1; 4) Genome-wide discovery and characterization of novel IRE1a substrates. To achieve these goals, the investigators will employ well-established and newly developed methodologies, including: mutant/transgenic plants studies, in planta fluorescent reporter-based microscopy, pathogen infections and cell death assays, protein-protein interaction and enzymatic assays, a novel yeast reporter-based system, transcriptional profiling, and bioinformatics-aided analyses.