Fondong Vincent N
Department of Biological Sciences, Delaware State University, Dover, DE 19901, USA.
Int J Mol Sci. 2025 Jun 17;26(12):5814. doi: 10.3390/ijms26125814.
Begomoviruses infect many crops and weeds globally, especially in the tropical and subtropical regions, where there are waves of epidemics. These begomovirus epidemics are frequently associated with three DNA satellites: betasatellites, alphasatellites, and deltasatellites. Except for the origin of replication, these satellites show no sequence identity with the helper begomovirus. Alphasatellites and betasatellites encode the α-Rep and βC1 proteins, respectively, while deltasatellites encode no proteins. α-Rep, which functions like the Rep of the helper begomoviruses, ensures alphasatellite replication autonomy, while betasatellites and deltasatellites depend wholly on the helper virus for replication. The betasatellite βC1 protein is a pathogenicity determinant and suppressor of RNA silencing. The associations between satellites and helper viruses vary, depending on the virus and the host, and the roles of these satellites in disease development are an active area of investigation. This review highlights current information on the role of DNA satellites in begomovirus diseases and examines commonalities and differences between and within these satellites under prevailing conditions. Furthermore, two episomes, SEGS-1 and SEGS-2, associated with cassava mosaic geminiviruses, and their possible status as DNA satellites are discussed. DNA satellites are a major factor in begomovirus infections, which are a major constraint to crop production, especially in tropical and subtropical regions. Thus, areas for future research efforts, as well as implications in the biotechnological management of these viruses, are discussed in this review.
双生病毒在全球感染许多作物和杂草,尤其是在热带和亚热带地区,这些地区疫情频发。这些双生病毒疫情通常与三种DNA卫星分子有关:β卫星分子、α卫星分子和δ卫星分子。除了复制起点外,这些卫星分子与辅助双生病毒没有序列同源性。α卫星分子和β卫星分子分别编码α-Rep和βC1蛋白,而δ卫星分子不编码任何蛋白。α-Rep的功能类似于辅助双生病毒的Rep蛋白,可确保α卫星分子的自主复制,而β卫星分子和δ卫星分子完全依赖辅助病毒进行复制。β卫星分子的βC1蛋白是致病性决定因子和RNA沉默抑制因子。卫星分子与辅助病毒之间的关联因病毒和宿主而异,这些卫星分子在疾病发展中的作用是一个活跃的研究领域。本综述重点介绍了关于DNA卫星分子在双生病毒病害中作用的当前信息,并研究了在当前条件下这些卫星分子之间以及内部的共性和差异。此外,还讨论了与木薯花叶双生病毒相关的两个附加体SEGS-1和SEGS-2及其作为DNA卫星分子的可能状态。DNA卫星分子是双生病毒感染的主要因素,双生病毒感染是作物生产的主要限制因素,尤其是在热带和亚热带地区。因此,本综述讨论了未来研究工作的方向以及这些病毒在生物技术管理中的意义。