The world population is projected to increase to over 9 billion people by 2050, necessitating a 70% increase in the food supply. Such a goal can only be accomplished by increasing the yields of the major crop plants, especially the cereals, whose grains meet substantial nutritional needs in the form of protein and starch for a significant portion of the world's population. Results from this research will provide new insights and innovative strategies to improve crop yields by manipulating the enzymes (proteins that facilitate chemical reactions) involved in the early steps of the production of the proteins and starch that are stored in rice grains. In addition, this project will provide state-of-the-art research training in molecular, cellular and genetic methods, especially large-scale studies of proteins (proteomics) and genes (genomics) for postdoctoral, graduate and undergraduate students, including students from a partnering minority-serving institution, California State University at Los Angeles. Products of this research will be integrated into a new website on molecular kinesis (how for example RNA and proteins move within plant cells to the sites where they function) an important topic that is poorly described in modern plant biology textbooks.
Although considerable information has been generated over the years on how plant genes are controlled at the transcriptional and post-transcriptional levels, very little is known about how RNAs are transported and localized to specific sub-compartments of the plant cell where they are translated, stored, processed or turned-over. This research will focus on the transport and localization of RNAs in developing rice endosperm with the aim of providing a comprehensive picture of the RNA binding proteins (RBPs) involved, how they are organized into multi-RBP complexes, and how RBPs that may be common factors of distinct RNA transport pathways may, nevertheless, provide the directions for targeting RNAs to particular individual pathways. This project will use genome-wide approaches to identify the role of specific RBPs in the transport and localization of RNAs to the cortical endoplasmic reticulum and their subsequent roles in translation, stability and/or RNA processing. Specific objectives will be to: (1) categorize cytoplasmic-localized, cytoskeletal-associated RBPs into multi-protein complexes; (2) determine the composition of RNAs bound by these multi-protein complexes and identify the associated cis-sequences; and (3) determine the role of modular domains of specific RBPs that may be responsible for specifying a particular RNA transport pathway by the analysis of genetic mutations. This information will provide an unprecedented view of the fate of RNAs and their location in the plant cell and will thereby fill a major gap in our understanding of steps in gene expression beyond transcription.
