High-throughput sequencing for deciphering the virome of alfalfa (Medicago sativa L.)

Authors: BEJERMAN, NICOLAS - Instituto Nacional Tecnologia Agropecuaria; ROUMAGNAC, PHILIPPE - Cirad, France; Nemchinov, Lev

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2020
Publication Date: 9/11/2020
Citation: Bejerman, N., Roumagnac, P., Nemchinov, L.G. 2020. High-throughput sequencing for deciphering the virome of alfalfa (Medicago sativa L.). Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2020.553109.
DOI: https://doi.org/10.3389/fmicb.2020.553109

Interpretive Summary: This review describes the most recent accomplishments in the field of alfalfa virology. Like most of the agricultural crops, alfalfa is a natural host for many plant viruses. Notwithstanding, among the groups of pathogens that infect alfalfa, viruses are the least recognized members. The goal of this review is to demonstrate that disregarding the role of viruses in alfalfa health could be impractical for alfalfa improvement and production. It is expected that the review will be of interest to plant pathologists and extension specialists working in the field of alfalfa improvement and to plant virologists and molecular biologists in general.

Technical Abstract: Alfalfa (Medicago sativa L.), also known as lucerne, is a major forage crop worldwide. In the United States, it has recently become the third most valuable field crop with an estimated worth of over $9.3 billion. Alfalfa is naturally infected with many different pathogens including viruses, obligate parasites that reproduce only inside living host cells. Traditionally, viral infections of alfalfa have been considered by producers, breeders, growers and researchers as diseases of limited importance, despite the fact that they are widespread in all major cultivation areas. However, over the past few years, due to the rapid development of high-throughput sequencing (HTS), viral metagenomics, bioinformatics tools to interpret massive amounts of HTS data, and accessibility of public data repositories for transcriptomic discoveries, several emerging viruses of alfalfa have been described with the potential to cause serious yield losses. They include alfalfa leaf curl virus (Geminiviridae family), alfalfa dwarf virus (Rhabdoviridae family), alfalfa enamovirus 1 (Luteoviridae family), alfalfa virus F (Tymoviridae family) and others. These discoveries questioned a low economic impact of viral diseases on alfalfa and furthermore suggested their potential contribution to the severity of complex infections involving multiple pathogens. In this review we will touch upon viral pathogens of alfalfa recently described in our respective laboratories by means of the above research methodologies.