Department of Plant Pathology, The Ohio State University, Wooster, OH, United States of America.
Corn, Soybean, and Wheat Quality Research Unit, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Wooster, OH, United States of America.
PLoS One. 2023 Feb 6;18(2):e0281484. doi: 10.1371/journal.pone.0281484. eCollection 2023.
Maize lethal necrosis is a destructive virus disease of maize caused by maize chlorotic mottle virus (MCMV) in combination with a virus in the family Potyviridae. Emergence of MLN is typically associated with the introduction of MCMV or its vectors and understanding its spread through seed is critical for disease management. Previous studies suggest that although MCMV is detected on seed, the seed transmission rate of this virus is low. However, mechanisms influencing its transmission are poorly understood. Elucidating these mechanisms is crucial for informing strategies to prevent spread on contaminated seed. In this study, we evaluated the rate of MCMV seed transmission using seed collected from plants that were artificially inoculated with MCMV isolates from Hawaii and Kenya. Grow-out tests indicated that MCMV transmission through seed was rare, with a rate of 0.004% among the more than 85,000 seed evaluated, despite detection of MCMV at high levels in the seed lots. To understand factors that limit transmission from seed, MCMV distribution in seed tissues was examined using serology and immunolocalization. The virus was present at high levels in maternal tissues, the pericarp and pedicel, but absent from filial endosperm and embryo seed tissues. The ability to transmit MCMV from seed to uninfected plants was tested to evaluate virus viability. Transmission was negatively associated with both seed maturity and moisture content. Transmission of MCMV from infested seed dried to less than 15% moisture was not detected, suggesting proper handling could be important for minimizing spread of MCMV through seed.
玉米坏死性萎蔫病是一种由玉米褪绿斑驳病毒（MCMV）与马铃薯 Y 病毒科（Potyviridae）病毒共同作用引起的破坏性玉米病毒病。MLN 的出现通常与 MCMV 或其载体的引入有关，了解其通过种子传播对于疾病管理至关重要。先前的研究表明，尽管在种子上检测到了 MCMV，但该病毒的种子传播率很低。然而，影响其传播的机制尚不清楚。阐明这些机制对于制定防止受污染种子传播的策略至关重要。在这项研究中，我们使用从夏威夷和肯尼亚的 MCMV 分离株人工接种的植株上采集的种子来评估 MCMV 的种子传播率。生长试验表明，尽管在种子批中检测到 MCMV 的水平很高，但通过种子传播 MCMV 的情况很少见，在所评估的 85000 多粒种子中，传播率仅为 0.004%。为了了解限制种子传播的因素，我们使用血清学和免疫定位技术检查了种子组织中 MCMV 的分布情况。病毒在母体组织、果皮和花梗中含量很高，但在子叶和胚乳种子组织中不存在。我们还测试了从种子向未感染植株传播 MCMV 的能力，以评估病毒的活力。传播与种子成熟度和含水量呈负相关。未检测到从受感染种子干燥至含水量低于 15%的 MCMV 传播，这表明正确处理可能对最大限度地减少 MCMV 通过种子传播很重要。
