Location: Emerging Pests and Pathogens Research
Project Number: 8062-22410-007-014-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jan 15, 2021
End Date: Jan 14, 2025
Objective:
This proposal will develop management tools for Cotton leafroll dwarf virus (CLRDV) from both the aphid and plant side of the pathosystem. Polerovirus structural data show that the N-terminus of the polerovirus readthrough domain protein (RTD), one of two viral structural proteins, has an evolutionarily conserved function in polerovirus transmission by aphids. Due to the highly conserved nature of the RTD structure in multiple polerovirus species, it's expected that the CLRDV RTD will block CLRDV transmission by the cotton aphid, a hypothesis that will be tested in this work. A transgenic cotton plant will be developed that expresses the CLRDV RTD and tested as to whether the transgenic plants block CLRDV transmission by aphids and/or kill the aphid vector, similar to what's been observed for PLRV. Mass spectrometry techniques will be used to identify cotton and cotton aphid proteins that bind to CLRDV. Identifying the plant and aphid proteins that interact with CLRDV is the first step towards precision breeding a CLRDV-resistant cotton plant using genome editing approaches. Research in this project will also lead to the development of an antibody test that can be used by growers for rapid and accurate identification of CLRDV-infected plants.
Approach:
An invasive polerovirus, Cotton leafroll dwarf virus (CLRDV) is an emerging threat to cotton in the United States. CLRDV is transmitted by the cotton aphid, Aphis gossypii, and possibly other vector species. There is a wealth of data on poleroviruses as a result of studies on Potato leafroll virus and the yellow dwarf viruses. The team is in a strong position to bring this knowledge to bear on CLRDV. The impact of CLRDV on cotton production is currently unknown, and management strategies are nonexistent. New approaches to control the spread of CLRDV, such as blocking aphid transmission, are needed to augment existing management strategies. In depth studies on CLRDV are needed to validate that this virus behaves similarly to other poleroviruses. This project will solve the macromolecular structure of the CLRDV structural protein that regulates aphid transmission and develop tools - transgenic cotton and an antibody test - that will protect the crop from aphid transmission of CLRDV. Proteomics will be used to identify plant and aphid proteins that bind to CLRDV, which is the first step towards generating genome-edited, CLRDV-resistant cotton. A major concern for the industry is the development of future management strategies, including testing and mitigation, which are the foci of this proposal. This proposal is submitted in response to The Cotton Board's CLRDV topic listed in the FY2020 AFRI Foundational Competitive Grants Program.
