Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
USDA/ARS, Beltsville Agricultural Research Center, Molecular Plant Pathology Laboratory, Beltsville, MD, 20705, USA.
Virol J. 2021 Sep 9;18(1):185. doi: 10.1186/s12985-021-01650-9.
Endogenous viral elements (EVEs) have been for the most part described in animals and to a less extent in plants. The endogenization was proposed to contribute toward evolution of living organisms via horizontal gene transfer of novel genetic material and resultant genetic diversity. During the last two decades, several full-length and fragmented EVEs of pararetroviral and non-retroviral nature have been identified in different plant genomes, both monocots and eudicots. Prior to this work, no EVEs have been reported in alfalfa (Medicago sativa L.), the most cultivated forage legume in the world. In this study, taking advantage of the most recent developments in the field of alfalfa research, we have assessed alfalfa genome on the presence of viral-related sequences. Our analysis revealed segmented EVEs resembling two dsDNA reverse-transcribing virus species: Soybean chlorotic mottle virus (family Caulimoviridae, genus Soymovirus) and Figwort mosaic virus (family Caulimoviridae, genus Caulimovirus). The EVEs appear to be stable constituents of the host genome and in that capacity could potentially acquire functional roles in alfalfa's development and response to environmental stresses.
内源性病毒元件（EVEs）在动物中已被大部分描述，在植物中则较少。内源性假说认为，通过新遗传物质的水平基因转移和由此产生的遗传多样性，有助于生物进化。在过去的二十年中，在不同的植物基因组中，包括单子叶植物和双子叶植物中，已经鉴定出了几种属于pararetroviral 和非逆转录病毒性质的全长和片段化的 EVEs。在此之前，在世界上种植最多的饲料豆科植物紫花苜蓿（Medicago sativa L.）中，尚未报告过 EVEs。在这项研究中，我们利用紫花苜蓿研究领域的最新进展，评估了紫花苜蓿基因组中是否存在与病毒相关的序列。我们的分析揭示了类似于两种 dsDNA 反转录病毒物种的分段 EVEs：大豆花叶病毒（Caulimoviridae 科，Soymovirus 属）和三色堇碎锦斑病毒（Caulimoviridae 科，Caulimovirus 属）。这些 EVEs 似乎是宿主基因组的稳定组成部分，并可能在紫花苜蓿的发育和对环境胁迫的反应中获得功能作用。
