Biology subjects

DeBlasio, S. L.

Publications and source records attributed to DeBlasio, S. L..

5 recordsLinked to original sources

bioRxiv2026

A scalable approach to inoculate plant viral vectors into plant tissue using non-pathogenic, transgenic galls

Vascular plant pathogens transmitted by insects inflict devastating economic losses on crops worldwide. By obstructing and usurping the natural flow of nutrients, plant infection by these pathogens drastically reduces yields, vigor and productivity. Treating fruit-bearing trees against persistent vascular pathogens poses a unique challenge, as systemic delivery of therapeutics must navigate the compartmentalized architecture of the trees vascular system under changing environmental conditions without disrupting fruit production or long-term tree health. Plant viruses have gained traction as a novel approach to deliver therapies to crop plants, including fruit trees, but delivery of viral vectors to orchards at scale remains a significant challenge. We tested whether transgenic galls can be used to systemically infect plants with a plant virus infectious clone. We combined the plant growth regulator gene cassette from Agrobacterium tumefaciens strain C58 with the wild-type strain of citrus yellow vein associated virus-1 (CY1) on a single plasmid within the T-DNA for plant cell transformation. Using EHA105, a disarmed strain of A. tumefaciens, we inoculated stems with these gall-forming plasmids and initiated systemic CY1 infection in citrus and Arabidopsis thaliana over three independent experiments. We provide proof-of-concept that transgenic galls, referred to as symbionts, can launch the systemic infection of CY1 in economically important and model plants. Symbiont delivery of therapeutic viral vectors is theoretically scalable from inoculation of mother trees within the nursery to millions of trees in the field and may be a valuable tool for the commercial delivery of therapeutic plant viral vectors.

plant biology↗

bioRxiv2025

Viral silencing suppressor activity in plants modifies aphid antiviral immunity and fecundity

Plants defend themselves from viral infection using RNA interference (RNAi), an evolutionarily conserved mechanism that degrades viral RNA through the production of small interfering RNAs. As a counter defense, plant viruses evolved suppressors of RNA silencing (VSRs) to inhibit plant RNAi machinery, aiding viral replication and transmission. P0, a VSR encoded by the potato leafroll virus (PLRV), family Polerovirus, suppresses RNAi by targeting the plant protein ARGONATE 1 for degradation through its F-box motif interaction with a Skp1 subunit of the family of E3 ubiquitin ligases. Our previous work shows PLRV P0 suppresses antiviral immunity in its aphid vector Myzus persicae, leading to an increase in aphid infection by the insect virus Myzus persicae densovirus (MpDNV). Here, we expand on these findings and show that the P0 protein also regulates aphid fecundity. Using a series of F-box mutants, we demonstrate that a functional P0 F-box motif is required for inhibition MpDNV antiviral immunity but not modulation of aphid fecundity. We further show that silencing suppressors from non-aphid-borne plant viruses that target other components of the plants RNAi machinery also modulate aphid fecundity but not MpDNV titer. Collectively, the results show that aphids have been favored by selection to modulate their anti-viral immunity and fecundity in response to changes in the plant RNAi pathways induced by plant viral infection. These data highlight the intricate co-evolution of plant viruses, their vectors, and host defenses. This knowledge may open new avenues for managing vector-borne plant diseases by targeting viral proteins to manipulate insect vectors.

microbiology↗

bioRxiv2023

Plant-derived, nodule-specific cysteine rich peptides inhibit growth and psyllid acquisition of 'Candidatus Liberibacter asiaticus', the citrus Huanglongbing bacterium

AbstractThe Asian citrus psyllid, Diaphorina citri, is a vector of Candidatus Liberibacter asiaticus (CLas), a gram-negative, obligate biotroph whose infection in Citrus species is associated with citrus greening disease, or Huanglongbing (HLB). Strategies to block CLas transmission by D. citri remain the best way to prevent the spread of the disease into new citrus growing regions. However, identifying control strategies to block HLB transmission poses significant challenges, such as the discovery and delivery of antimicrobial compounds targeting the bacterium and overcoming consumer hesitancy towards accepting the treatment. Here, we computationally identified and tested a series of 20-mer nodule-specific cysteine-rich peptides (NCRs) derived from the Mediterranean legume, Medicago truncatula Gaertn. (barrelclover) to identify those peptides that could effectively prevent or reduce CLas infection in citrus leaves and/or prevent CLas acquisition by the bacteriums insect vector, D. citri. A set of NCR peptides were tested in a screening pipeline involving three distinct assays: a bacterial culture assay, a CLas-infected excised citrus leaf assay, and a CLas-infected nymph acquisition assay that included D. citri nymphs, the only stage of D. citris life-cycle that can acquire CLas leading to the development of vector competent adult insects. We demonstrate that a subset of M. truncatula-derived NCRs inhibit both CLas growth in citrus leaves and CLas acquisition by D. citri from CLas-infected leaves. These findings reveal NCR peptides as a new class and source of biopesticide molecules to control CLas for the prevention and/or treatment of HLB.

plant biology↗

bioRxiv2022

Polerovirus N-terminal readthrough domain structures reveal novel molecular strategies for mitigating virus transmission by aphids

Poleroviruses, enamoviruses, and lutoeviruses are icosahedral, positive sense RNA viruses that cause economically important diseases in food and fiber crops. They are transmitted by phloem-feeding aphids in a circulative manner that involves the movement across and within insect tissues. The N-terminal portion of the viral readthrough domain (NRTD) has been implicated as a key determinant of aphid transmission in each of these genera. Here, we report crystal structures of the NRTDs from the poleroviruses turnip yellow virus (TuYV) and potato leafroll virus (PLRV) at 1.53-[A] and 2.22-[A] resolution, respectively. These adopt a two-domain arrangement with a unique interdigitated topology and form highly conserved dimers that are stabilized by a C-terminal peptide that is critical for proper folding. We demonstrate that the PLRV NRTD can act as an inhibitor of virus transmission and identify NRTD mutant variants that are lethal to aphids. Sequence conservation argues that enamovirus and luteovirus NRTDs will follow the same structural blueprint, which affords a novel approach to block the spread of these agricultural pathogens in a generalizable manner.

plant biology↗

bioRxiv2020

The innate immunity protein C1QBP functions as a negative regulator of circulative transmission of Potato leafroll virus by aphids

The vast majority of plant viruses are transmitted by insect vectors with many crucial aspects of the transmission process being mediated by key protein-protein interactions. Yet, very few vector proteins interacting with virus have been identified and functionally characterized. Potato leafroll virus (PLRV) is transmitted most effectively by Myzus persicae, the green peach aphid, in a circulative, non-propagative manner. Using an affinity purification strategy coupled to high-resolution mass spectrometry (AP-MS), we identified 11 proteins from M. persicae displaying high probability of interaction with PLRV and an additional 23 vector proteins with medium confidence interaction scores. Two of these proteins were confirmed to directly interact with the structural proteins of PLRV and other luteovirid species via yeast two-hybrid with an additional vector protein displaying binding specificity. Immunolocalization of one of these direct PLRV-interacting proteins, an orthologue of the human innate immunity protein complement component 1 Q subcomponent-binding protein (C1QBP), shows that MpC1QBP partially co-localizes with PLRV within cytoplasmic puncta and along the periphery of aphid gut epithelial cells. Chemical inhibition of C1QBP in the aphid leads to increased PLRV acquisition and subsequently increased titer in inoculated plants, supporting the role of C1QBP as a negative regulator of PLRV accumulation in M. persicae. We hypothesize that the innate immune function of C1QBP is conserved in aphids and represents the first instance of aphids mounting an immune response to a non-propagative plant virus. This study presents the first use of AP-MS for the in vivo isolation of functionally relevant insect vector-virus protein complexes.

microbiology↗