Biology subjects

Grinstead, S.

Publications and source records attributed to Grinstead, S..

5 recordsLinked to original sources

bioRxiv2026

Genome-wide identification of rhabdoviral sequences in alfalfa (Medicago sativa L.)

We recently reported the identification of endogenous viral elements (EVEs) originating from the Caulimoviridae family within the alfalfa (Medicago sativa L.) genome. Our subsequent identification of ubiquitous rhabdoviral elements in infected and healthy alfalfa tissues by high throughput sequencing prompted us to suggest that the alfalfa genome might be populated with integrated rhabdoviruses as well. Bioinformatics analysis using 26 publicly available alfalfa genomes proved the suggestion accurate. We found multiple non-retroviral segments of the Rhabdoviridae family belonging to the genera Betanucleorhabdovirus and Betacytorhabdovirus that appeared to be stable constituents of the host genome. In that capacity they could potentially acquire functional roles in alfalfas development and response to environmental stresses. We believe this study reveals the first documented case of rhabdoviruses integrated into the alfalfa genome.

genomics↗

bioRxiv2025

Alfalfa transcriptomic responses to the field pathobiome

The pathobiome is a comprehensive biotic environment that includes a community of all disease-causing organisms within the plant, defining their mutual interactions and the resultant effect on plant health. We have previously reported on the diverse composition of the alfalfa pathobiome in the field production environment. We have also briefly addressed host reactions to a consortium of pathogenic microorganisms by profiling gene expression patterns shaped by the plant pathobiome in the field. In this study, we expand on the field host genomics approach by surveying gene expression changes in visually healthy and diseased plants collected from different commercial alfalfa fields. In addition to offering insights into the genetic basis of host resistance to multi-pathogenic infections in natural ecosystems, this strategy can also help to identify plants with tolerant genotypes adapted to field pathobiome that could be used in breeding programs.

plant biology↗

bioRxiv2023

Alfalfa vein mottling virus, a novel potyvirid infecting Medicago sativa L.

We have recently identified a novel virus detected in alfalfa seed material. The virus was tentatively named alfalfa-associated potyvirus 1, as its genomic fragments bore similarities with potyvirids. In this study, we obtained a complete genome sequence of the virus and classified it as a tentative species in the new genus, most closely related to the members of the genus Ipomovirus in the family Potyviridae. This assumption is based on the genome structure, phylogenetic relationships, transmission electron microscopy investigations and, in part, on serological cross-reactivity of the virus. We also demonstrated its mechanical transmission to the indicator plant Nicotiana benthamiana and to the natural host Medicago sativa, both of which developed characteristic symptoms therefore suggesting a pathogenic nature of the disease. Consistent with symptomatology, the virus was renamed to alfalfa vein mottling virus. A name Alvemovirus was proposed for the new genus in the family Potyviridae, of which alfalfa vein mottling virus is a tentative member.

microbiology↗

bioRxiv2020

Genetic characterization of a mild isolate of papaya ringspot virus type-P (PRSV-P) and assessment of its cross-protection potential under greenhouse and field conditions

A mild isolate of Papaya ringspot virus type-P, abbreviated as PRSV-mild, from Ecuador was sequenced and characterized. The most distinguishing symptom induced by PRSV-mild was gray powder-like leaf spots radiating from secondary veins. In greenhouse experiments, PRSV-mild did not confer durable protection against a severe isolate of the virus (PRSV-sev), obtained from the same field. Furthermore, isolate specific detection in cross-protected plants showed that PRSV-sev becomes dominant in infections, rendering PRSV-mild undetectable at 90 - 120 days post superinfection. Virus testing using isolate-specific primers detected PRSV-mild in two out of five surveyed provinces, with 10% and 48% of incidence in Santo Domingo and Los Rios, respectively. Comparative genomics showed that PRSV-mild lacks two amino acids from the coat protein region, whereas amino acid determinants for asymptomatic phenotypes were not identified. Recombination events were not predicted in the genomes of the Ecuadorean isolates. Phylogenetic analyses placed both PRSV-mild and PRSV-sev in a clade that includes an additional PRSV isolate from Ecuador and others from South America.

microbiology↗

bioRxiv2019

Characterization of a new cytorhabdovirus discovered in papaya (Carica papaya) plantings of Ecuador and its relationship with a bean-infecting strain from Brazil

The complete genome of a new rhabdovirus infecting papaya (Carica papaya L.) was sequenced and characterized. The genome consists of 13,469 nucleotides with six canonical open reading frames (ORFs) predicted from the antigenomic strand. In addition, two overlapping short ORFs were predicted between ORFs 3 and 4. Phylogenetic analyses using amino acid sequences from the nucleocapsid, glycoprotein and polymerase, grouped the virus with members of the genus Cytorhabdovirus, with rice stripe mosaic virus, yerba mate chlorosis-associated virus and Colocasia bobone disease-associated virus as closest relatives. The 3 leader and 5 trailer sequences were 144 and 167 nt long, respectively. Each end contains complementary sequences prone to form panhandle structures. The motif 3-AUUCUUUUUG-5, conserved across rhabdoviruses, was identified in all but one intergenic regions; whereas the motif 3-ACAAAAACACA-5 was found in three intergenic junctions. This is the first complete genome of a cytorhabdovirus infecting papaya. The virus was prevalent in commercial plantings of Los Rios, the most important papaya producing province of Ecuador. During the final stage of this manuscript preparation, the genome of a bean-associated cytorhabdovirus became available. Nucleotide identity (97%) between both genomes indicated that the two viruses are strains of the same species, for which we propose the name papaya cytorhabdovirus E.

microbiology↗