SBIR Phase I: Creating a Master Transformation Recipient Line for Chloroplast Engineering of Maize

The broader impact of this Small Business Innovation Research (SBIR) Phase I project is to develop environmentally sustainable, higher yielding, pest-resistant biotech crops. Crops of the future need dozens of traits to achieve higher yields and protect themselves against insects, pests, diseases and changing environmental conditions. The proposed technology will enable efficient production of crops engineered with multiple trait genes, higher efficacy of the desired traits, and faster breeding and seed production to accelerate distribution. Unlike current solutions, the proposed technology ensures that traits will not be transferred to weeds or native plant species via pollen. The initial application is corn, the most valuable commercial crop in the US, with insights expected to enhance other crops. The proposed project aims to create a chloroplast (plastid) transformation platform for engineering corn. Although chloroplast engineering (transplastomic) technology has been developed successfully in a number of dicot crop species (i.e., tobacco, potato), a reproducible technology has not been developed for any monocot crop (i.e., corn, sorghum). The available evidence indicates that the rate-limiting step is the need for a strong selection system to enable the identification and amplification of rare transformed plastids in the embryogenic tissue culture systems typical for monocots. This project will create a Master Transformation Recipient Line (MTRL) of corn for use in a chloroplast engineering platform. The MTRL will contain a targeted genome deletion in a chloroplast-encoded photosynthetic gene, allowing for development of a new selection system that can lead to successful chloroplast engineering of monocot crops. Ultimately, the corresponding wild-type chloroplast photosynthetic gene will be delivered to the MTRL with other desired traits, facilitating an elegant selection of transformed plastids with the deleted photosynthetic gene restored and as well as carrying the new traits of interest. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.