The primary aim of this research is to investigate how the RNA degrading machinery of a model plant is controlled. Specifically, the compartmentalization of ribonucleases (RNase in Arabidopsis, and the temporal and spacial constrains on RNase activity will be studied. Our initial experiments have identified 15 RNase activities from Arabidopsis using a substrate-based gel assay. We plan to investigate the compartmentalization of these enzymes by gradient fractionation and organellar purification. RNases associated with vacuoles, nuclei, chloroplasts, and polysomes will be identified. For one or more selected RNases, protein purification will be performed and antiserum will be raised and used for further analyses. Preliminary studies indicate that some RNases accumulate differentially in Arabidopsis. THerefore, the RNase profiles in different organs will be compared at different stages of development, and under different environmental conditions. Beyond it contribution to basic knowledge, this research should enhance the potential use of Arabidopsis as a genetic model to study the functions of individual RNases in the future.//
