Understanding Regulatory Mechanisms of ERF/AP2 Transcription Factor Activity in Higher Plants

Washington State University, Pullman WA

Investigators

Abstract

Intellectual merit. Growth of sessile plants depends on accurate and timely cellular responses to environmental changes. In the face of global climate change, which is leading to further regional extremes in temperature and precipitation [e.g. more hot extremes, fewer cold extremes, severe drought, flooding (The Copenhagen Diagnosis, 2009)], understanding how plants achieve stress tolerance will become ever more important. Cellular responses to environmental change depend on and are facilitated by transcription factors that serve as response mediators by activating or repressing gene expression. It has been demonstrated that transcription factors can be regulated through the ubiquitin proteasome pathway. This highly conserved system in eukaryotic cells facilitates recognition and degradation of protein substrates. A major transcription factor family specific to plants, which plays a key role in development and abiotic stress tolerance (drought, heat, cold, and salinity) is represented by the AP2/ERF family. Recent work has shown that members of this family can interact with a set of adapter proteins, called BPMs, which are known to assemble into a complex that participates in recognition and tagging of substrates for proteasomal degradation. This project will study how BPM substrate adaptors act to regulate AP2/ERF transcription factors and the resulting impacts on developmental processes and stress responses in plants. The specific aims of this project are 1) to determine the specificity of BPM assembly with ERF/AP2 transcription factors, including interaction patterns and locations, 2) to determine how BPM-ERF/AP2 interaction may mediate transcriptional activity and 3) to determine the impact of BPM function on plant phenotype. Overall, the work will generate new knowledge about novel regulatory mechanisms affecting transcriptional activities in plants. In addition, because the BPM proteins have orthologs in animals, this knowledge will be applicable across a broad range of fields. Broader impacts. Due to the rapidly changing environment across the globe, knowledge of how regulatory processes affect plant performance becomes increasingly important. The proposed work will further our understanding of how the control of gene expression impacts plant growth and stress resistance. Due to the conserved nature of the proteasome degradation pathway across kingdoms of life, the proposed work has the potential to provide new, interdisciplinary information relevant to a broad scientific community. This project will impact student education by both building on the current knowledge base and by directly involving students in the research. Besides training graduate and postgraduate students, it will foster training of undergraduate students with an emphasis on the recruitment of underrepresented minorities. The undergraduate students will be able to accomplish smaller objectives within the framework of this project. They will learn a wide range of technical approaches and will be involved in extensive discussions about their research and how it relates to the current work in the field. The project will also give students the opportunity to disseminate their results during WSU campus activities, such as the WSU Annual Undergraduate Student Poster Competition and the WSU Showcase, or at national meetings. In general, the project will provide students with a valuable experience, important for their future careers in the sciences. Hence, while advancing our understanding of molecular mechanisms in plants, the project will strongly promote student teaching and training and will thereby also have broad, positive societal and educational impacts.