Mechanisms of Plant Steroid Hormone Regulated Gene Expression in Arabidopsis

Iowa State University, Ames IA

Investigators

Abstract

Plant steroid hormones, Brassinosteroids (BRs), play important roles in plant growth, development and response to environmental stresses. BRs act through several signaling components to regulate BES1/BZR1 and other families of transcription factors (TFs), which in turn control the expression of about 4000 genes required for various BR responses. How BR-regulated TFs control the expression of the large number of target genes and various BR responses is not well defined and will be the main focus of the proposal. The functions and mechanisms of several BR-regulated transcription factors (proteins responsible for activating or inactivating genes) will be studied by reverse genetic and genomic approaches and their regulation by BR signaling will be investigated by biochemical experiments. The results will reveal how each of the BR-regulated TFs controls a subset of BR target genes and a portion of BR responses. The studies will also provide important insight into how BR signal is integrated into the complex transcriptional network to control various BR-regulated processes. The knowledge obtained can be used to design strategies to improve the crop yield and tolerance to environmental stresses. Both mutants and transgenic lines generated from the project will be made available through the Arabidopsis Information Resource. In addition, the large-scale gene expression data will be deposited into NASC Arrays or GEO Datasets for wide dissemination. The proposed research will generate new knowledge that is essential for agriculture and bioenergy, especially under the constant environmental changes. In addition, a graduate student, research assistant and high school teacher will be trained to carry out the proposed experiments as a coordinated and cohesive team. The high school biology teacher will also be trained to bring some of the BR mutants to high school biology classes. The proposal, therefore, has a great potential in training future scientists and educators.