Plants are capable of producing a great diversity of relatively small organic chemicals that are called “secondary”, or, more recently, “specialized” metabolites, because they are not involved in central metabolism (Gang, 2005; Weng and Noel, 2012). Currently, well over 200,000 distinct molecules are known to be produced by plants and found to serve many important roles. As pigments, scents, and flavors they attract pollinators and seed dispersers (Gang, 2005). They can also be signaling molecules for symbiotic interactions or deter various pathogens and/or herbivores (Dixon, 2001; Jander and Clay, 2011). Thus, specialized phytochemicals orchestrate plant interactions with the ecosystem and are critical to plant fitness, survival, and propagation. Despite the fact that plants are a rich source of novel molecules, valuable to both basic and applied sciences, only a fraction of the pathways and compounds in plants have been explored. The project proposed here seeks to discover novel plant-produced natural products with unique and valuable properties, as well as the genes and pathways involved in their synthesis. At the core of this effort is an extensive living Plant Cell Culture Library (PCCL) that was recently (2014) donated to UMass by Monsanto (Figure 1).
The PCCL is the largest and most diverse collection of cultured plant species in the world, comprising over 2000 species, and is, therefore a unique asset for investigation of plant-specialized metabolites.
The long-term goal of this project is to discover new small molecules of value to agriculture as natural pesticides (insecticides, fungicides, nematicides, herbicides) or otherwise promoters of crop health, productivity, and biosafety. Major losses of agricultural products are due to insect and microbial pests, and finding new chemicals that are safe for the environment is of paramount importance for agriculture worldwide. The proposed work will provide the foundation and proof of concept for these efforts by: 1) Developing the least time- and reagent-intensive methods for maintaining this vast and diverse living collection; 2) Establishing procedures for production and extraction of secondary metabolites; 3) Initiating screens for compounds with bioactivity against selected plant pathogenic fungi and nematodes; and 4) Obtaining genomic and transcriptomic sequence data for five or more plant species in the PCCL in order to begin to define the genes involved in production of diverse metabolites. Developing plant cell extraction techniques and assays for bioactivity will involve extensive collaborations on campus, including with other members of the BMB Department and with the Stockbridge School of Agriculture. Information about the PCCL will be made available through a dedicated website (pcc.library.umass.edu) so that others in the academic and industrial community can request plant material or extracts. Presentations at scientific meetings and publications in appropriate journals will be used to report and disseminate results.