MOLECULAR MECHANISMS AND APPLICATIONS OF PLANT ANTIVIRAL DEFENSES

The long-term goal of this Hatch project is to understand the molecular mechanisms of plant antiviral defenses and use the knowledge to control diseases of crop plants caused by viruses, and contribute to the security of global food supply. Research efforts towards this long term goal comprise three primary research directions: I) basic research to elucidate the mechanisms of cross protection and superinfection exclusion, two inter-related phenomena occurring in the plant cells infected by most viruses; II) applied research to enhance the antiviral defense capabilities of crop plants taking advantage of our understanding of plant antiviral defense mechanisms, as well as new crop modification technologies such as CRISPR; and III) applied research using plant viruses as tools to discover resistance genes (R genes) against nonviral pathogens (e.g. Phytophthora sojae) of crop plants. I. Molecular mechanisms of crop protection and superinfection exclusion in virus-infected plant cells. This is the main focus of our research that is being funded by a recent grant from National Science Foundation (NSF). Details of this project are provided under the sections I of Project Descriptions.II. Engineering crop plants for enhanced antiviral resistance.This research direction harnesses the findings of our basic research to enhance the antiviral potentials of crop plants through biotechnological means, especially the new CRISPR/Cas9 technology. We currently have two funded projects under this direction. The first is funded by North Central Soybean Research Program (NCSRP), and explores the feasibility of using CRISPR base editing to modify existing soybean genes in order to gain tolerance to various herbicides. The second is supported by a Partnership grant jointly funded by the Ohio Agricultural Research and Development Center (OARDC) and Ohio Soybean Council (OSC), exploring ways to use viruses to accelerate the CRISPR gene editing. Details of this project are provided under section II of Project Descriptions.III. Using plant viruses as tools to discover resistance genes (R genes) against nonviral pathogens of crop plants.We recently succeeded in modifying two different viruses, namely Bean pod mottle virus (BPMV) and Apple latent spherical virus (ALSV), into robust vectors to induce the down-regulation (silencing) of soybean genes, and to express other bio-active peptides and proteins in soybean. This research direction is being pursued in close collaboration with Dr. Anne Dorrance in the OARDC Department of Plant Pathology. We have support for this research from OSC, as well as through the multi-PI grant led by Dr. Dorrance, and funded by the United Soybean Board (USB). Details for this direction is provided in section III of Projection Descriptions.