Plant responses to environmental stimuli: A screen for mutants aberrant in TCH4 expression behavior, and a full-genome assessment of touch and darkness inducibility
Doctor of Philosophy
Plants must be capable of detecting and responding to a wide variety of environmental stimuli, yet much remains to be determined about the mechanisms by which these processes occur. I describe herein a proof-of-concept mutant screen for identifying mutants aberrant in their responses to a variety of stimuli including heat, cold, touch, and darkness. Such mutants will undoubtedly serve as tools to investigate the molecular pathways by which plants detect and respond to their environment. In addition, I also describe a large-scale gene expression experiment utilizing Affymetrix ATH1 microarrays which focuses on the short-term responses of plants to touch and darkness. These chips enable an expression level survey of over 22,000 genes simultaneously. We identify 589 genes that have increased expression in plants 30 minutes after touch stimulation and 171 genes that have decreased expression. We also identify 461 genes that have increased expression in plants after 30 minutes of darkness treatment and 72 genes that have decreased expression. The identities of the regulated genes suggest that calcium and kinase signaling, cell wall modification, disease resistance and secondary transcriptional responses may be altered in plants subjected to mechanostimulation or darkness.