Kreuze Jan F, Perez Ana, Gargurevich Marco Galvez, Cuellar Wilmer J
Virology laboratory, International Potato Center (CIP), Lima, Peru.
Front Plant Sci. 2020 Mar 31;11:313. doi: 10.3389/fpls.2020.00313. eCollection 2020.
Sweet potato is among the most important root crops worldwide, particularly in developing countries, and its production is affected severely by a variety of virus diseases. During the last decade, a number of new viruses have been discovered in sweet potatoes through next-generation sequencing studies. Among them are viruses belonging to the genus and collectively assigned to the species (SPPV). We determined the complete genome sequence of two SPPV isolates and show the ubiquitous presence of similar viruses in germplasm and field material from around the globe. We show that SPPV is not integrated into the sweet potato genome, occurs only at extremely low titers, and is efficiently transmitted through seeds and cuttings. They are unaffected by virus elimination therapy and do not induce discernible symptoms in sweet potatoes or indicator host plants. They show considerable variation in their nucleotide sequences and correspond to several genetic lineages. Studies of their interaction with the two most important sweet potato viruses showed only limited synergistic increase in the titers of one of two SPPV isolates. We contend that these viruses may pose little threat to sweet potato production and more likely represent a new type of persistent virus in sweet potato.
甘薯是全球最重要的块根作物之一，在发展中国家尤为如此，其产量受到多种病毒病的严重影响。在过去十年中，通过新一代测序研究在甘薯中发现了许多新病毒。其中有属于该属的病毒，并统称为种（SPPV）。我们测定了两个SPPV分离株的完整基因组序列，并表明类似病毒在全球各地的种质和田间材料中普遍存在。我们发现SPPV未整合到甘薯基因组中，仅以极低滴度存在，并且能通过种子和插条有效传播。它们不受病毒清除疗法的影响，在甘薯或指示寄主植物中不诱发明显症状。它们的核苷酸序列存在相当大的变异，并对应于几个遗传谱系。对它们与两种最重要的甘薯病毒相互作用的研究表明，两种SPPV分离株之一的滴度仅有限地协同增加。我们认为这些病毒可能对甘薯生产构成的威胁很小，更有可能代表甘薯中的一种新型持久性病毒。
