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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #411077
Research Project: Integrated Crop Disease Mitigation through Improved Understanding of Relationships between Genetics, Environment, and Management

Location: Soil Dynamics Research

Title: A newly isolated cotton-infecting Polerovirus with cryptic pathogenicity encodes a weak suppressor of RNA silencing

Author
item AKINYUWA, MARY - Auburn University
item PRICE, BAILEE - Auburn University
item MARTIN, KATHLEEN - Auburn University
item KANG, SUNG-HWAN - Auburn University

Submitted to: Frontiers in Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2023
Publication Date: 7/24/2023
Citation: Akinyuwa, M., Price, B., Martin, K., Kang, S. 2023. A newly isolated cotton-infecting Polerovirus with cryptic pathogenicity encodes a weak suppressor of RNA silencing. Frontiers in Agronomy. 5:1235168. https://doi.org/10.3389/fagro.2023.1235168.
DOI: https://doi.org/10.3389/fagro.2023.1235168

Interpretive Summary: Cotton is a multipurpose major crop grown globally for multipurpose. One of the major diseases of cotton is caused by a viral pathogen, Cotton leafroll dwarf virus (CLRDV). CLRDV is transmitted by aphids and replicates within phloem-associated tissue. Previously, substantial economic losses in South American countries inflicted by CLRDV prompted research based on molecular characterization of its protein functioning as a viral suppressor of RNA silencing (VSR). Recently, a new strain of CLRDV was identified in the United States (CLRDV-AL). Interestingly, CLRDV-AL showed cryptic pathogenicity, making it hard to diagnose and detect in the field. Collaborators from Auburn Univ. of ARS scientists in Auburn, AL investigated the VSR of CLRDV-AL and demonstrated its weak potency as a VSR compared to other CLRDV strains. Amino acid substitutions within the functional domain of the protein attributed to this difference, and potential emergence of a more damaging form of the virus variant is stressed. Results from this study contributed to development of a better management strategy by elucidating the pathogenicity via host-pathogen interaction, including host immune response.

Technical Abstract: Cotton is a multipurpose crop grown globally, including the United States. Cotton leafroll dwarf virus (CLRDV), a phloem-limited virus (Solemoviridae) transmitted by aphids, causes significant economic losses to cotton cultivation. CLRDV strains (CLRDV-typical and atypical) that were previously prevalent in other countries cause severe symptoms leading to high yield loss. Recently, a new isolate of CLRDV (CLRDV-AL) has been characterized from infected cotton plants in Alabama that are often asymptomatic and difficult to detect, implying a low titer and pathogenicity within the host. Different pathogenicity among certain strains within the same species often correlates with both environmental and molecular factors. Thus, better management and control of the vector-borne disease can be achieved by elucidating host-pathogen interaction, such as host immune response and pathogen counter-response. In this study, we demonstrate the ability of CLRDV-AL to suppress a major host defense response known as RNA silencing and compare the potency of silencing suppression to other strains of the same virus. Also, we discuss the difference in pathogenicity among them by evaluating the observations based on the amino acid variation within the functional domain. Our study provides and suggests a future direction for specifying the strategy to mitigate potential cotton disease severity.