Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE 68503, U.S.A.
Center for Advanced Technology and Population Ecology Lab, Institute of Environmental Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland.
Phytopathology. 2024 Jul;114(7):1672-1679. doi: 10.1094/PHYTO-02-24-0073-R. Epub 2024 Jul 2.
Triticum mosaic virus (TriMV; genus ; family ) is an economically important virus in the Great Plains region of the United States. TriMV is transmitted by the wheat curl mite () Type 2 genotype but not by Type 1. Helper component-proteinase (HC-Pro) is a vector transmission determinant for several potyvirids, but the role of HC-Pro in TriMV transmission is unknown. In this study, we examined the requirement of the HC-Pro cistron of TriMV for wheat curl mite (Type 2) transmission through deletion and point mutations and constructing TriMV chimeras with heterologous HC-Pros from other potyvirids. TriMV with complete deletion of HC-Pro failed to be transmitted by wheat curl mites at detectable levels. Furthermore, TriMV chimeras with heterologous HC-Pros from aphid-transmitted turnip mosaic virus and tobacco etch virus, or wheat curl mite-transmitted wheat streak mosaic virus, failed to be transmitted by wheat curl mites. These data suggest that heterologous HC-Pros did not complement TriMV for wheat curl mite transmission. A decreasing series of progressive nested in-frame deletions at the N-terminal region of HC-Pro comprising amino acids 3 to 125, 3 to 50, 3 to 25, 3 to 15, 3 to 8, and 3 and 4 abolished TriMV transmission by wheat curl mites. Additionally, mutation of conserved His, Cys, or Cys to Ala in HC-Pro abolished TriMV transmissibility by wheat curl mites. These data suggest that the N-terminal region of HC-Pro is crucial for TriMV transmission by wheat curl mites. Collectively, these data demonstrate that the HC-Pro cistron of TriMV is a viral determinant for wheat curl mite transmission.
小麦梭条花叶病毒（TriMV；属；科）是美国大平原地区一种具有重要经济意义的病毒。TriMV 通过麦岩螨（）2 型基因型传播，但不通过 1 型传播。辅助蛋白水解酶（HC-Pro）是几种马铃薯 Y 病毒科病毒的载体传播决定因素，但 HC-Pro 在 TriMV 传播中的作用尚不清楚。在这项研究中，我们通过缺失和定点突变以及构建具有来自其他马铃薯 Y 病毒科的异源 HC-Pro 的 TriMV 嵌合体，研究了 TriMV 的 HC-Pro 顺式元件对麦岩螨（2 型）传播的要求。完全缺失 HC-Pro 的 TriMV 无法在可检测水平上被麦岩螨传播。此外，具有来自蚜虫传播的芜菁花叶病毒和烟草蚀纹病毒或麦岩螨传播的小麦线条花叶病毒的异源 HC-Pro 的 TriMV 嵌合体也无法被麦岩螨传播。这些数据表明异源 HC-Pro 不能补充 TriMV 用于麦岩螨传播。在 HC-Pro 的 N 端区域进行一系列连续的、嵌套的、框内缺失，从氨基酸 3 到 125、3 到 50、3 到 25、3 到 15、3 到 8 和 3 到 4，这些缺失使 TriMV 无法被麦岩螨传播。此外，HC-Pro 中保守的 His、Cys 或 Cys 突变为 Ala 也使 TriMV 的可传播性丧失。这些数据表明，HC-Pro 的 N 端区域对于 TriMV 通过麦岩螨传播至关重要。总的来说，这些数据表明 TriMV 的 HC-Pro 顺式元件是其通过麦岩螨传播的病毒决定因素。
