Biology subjects

Nemchinov, L. G.

Publications and source records attributed to Nemchinov, L. G..

4 recordsLinked to original sources

bioRxiv2026

Characterization of the alfalfa pollen virome

Vertical transmission of plant pathogenic viruses is an important component of viral persistence, survival, and spread in agricultural production systems. This type of transmission is of considerable economic significance as it can cause major crop losses by serving as the initial focus of infection for future epidemics. Vertical transmission occurs when a virus is passed on to offspring either by direct invasion of the developing seed embryo from infected mother plants or through infected pollen grains after fertilization. We have recently demonstrated by high throughput sequencing that mature seeds of the agriculturally important forage crop alfalfa (Medicago sativa L.) are associated with a broad range of viruses some of which could potentially spread over long distances via seed. Aside from alfalfa mosaic virus, little is currently known about viral transmission via alfalfa pollen and its role in the epidemiology in this crop. This research was conducted to screen the pollen obtained from unique alfalfa genotypes for the presence of pathogenic viruses and their potential for dissemination. The plants from which the pollen was collected were alfalfa genotypes selected for fungal plant disease resistance and agronomic performance in a USDA ARS pre-breeding program in Prosser, WA.

microbiology↗

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↗

bioRxiv2022

Snake River alfalfa virus, a tentative endorna-like virus infecting alfalfa (Medicago sativa L.) in Washington State, USA

Here we report, for the first time, an occurrence of Snake River alfalfa virus (SRAV) in Washington state, USA. SRAV was recently identified in alfalfa (Medicago sativa L.) plants and western flower thrips in south-central Idaho and proposed to be a first flavi-like virus identified in a plant host. We argue that the SRAV, based on its abundance in alfalfa plants, genome structure, presence in alfalfa seeds, and seed-mediated transmission is a member of the Endornaviridae family.

microbiology↗