Potato yellow vein virus (PYVV) was detected in potatoes grown in the Central highlands, north of Bogotá (~3000 m altitude), Colombia. At this altitude viral whitefly vectors are largely absent, but infection persists because of the use of uncertified tubers. Plants with typical PYVV-induced yellowing symptoms, as well as with atypical yellowing or non-symptomatic symptoms were sampled at three separate geographical locations. PYVV presence was assessed by RT-PCR, and several plants were subjected to high-throughput sequencing (HTS) of their small RNA (sRNA) populations. Complete or almost complete sequences of four PYVV isolates were thus reconstructed, all from symptomatic plants. Three viral isolates infected plants singly, while the fourth co-infected the plant together with a potyvirus. Relative proportions of sRNAs to each of the three crinivirus genomic RNAs were found to remain comparable among the four infections. Genomic regions were identified as hotspots of sRNA formation, or as regions that poorly induced sRNAs. Furthermore, PYVV titres in the mixed versus single infections remained comparable, indicating an absence of synergistic/antagonistic effects of the potyvirus on the accumulation of PYVV. Daughter plants raised in the greenhouse from tubers of the infected, field-sampled plants displayed mild PYVV infection symptoms that disappeared with time, demonstrating the occurrence of recovery and asymptomatic infection phenotypes in this pathosystem.

中文翻译：

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哥伦比亚高地马铃薯黄脉 crinivirus 感染的分子学研究

马铃薯黄脉病毒(PYVV) 在哥伦比亚波哥大北部（海拔约 3000 米）中部高地种植的马铃薯中检测到。在这个海拔高度，病毒粉虱载体基本上不存在，但由于使用未经认证的块茎，感染持续存在。在三个不同的地理位置对具有典型 PYVV 诱导的黄化症状以及非典型黄化或无症状症状的植物进行采样。通过 RT-PCR 评估 PYVV 的存在，并对一些植物进行了小 RNA (sRNA) 种群的高通量测序 (HTS)。因此重建了四个 PYVV 分离株的完整或几乎完整序列，全部来自有症状的植物。三个病毒分离株单独感染植物，而第四个病毒分离株与盆栽病毒共同感染植物。发现 sRNA 与三种 crinivirus 基因组 RNA 中每一种的相对比例在四种感染中保持可比性。基因组区域被确定为 sRNA 形成的热点，或作为 sRNA 诱导不良的区域。此外，混合感染与单一感染中的 PYVV 滴度仍保持可比性，表明不存在 Potyvirus 对 PYVV 积累的协同/拮抗作用。从受感染的田间取样植物的块茎在温室中培育的子代植物表现出轻微的 PYVV 感染症状，随着时间的推移消失，表明在该病理系统中出现了恢复和无症状感染表型。混合感染与单一感染中的 PYVV 滴度保持可比性，表明不存在 Potyvirus 对 PYVV 积累的协同/拮抗作用。从受感染的田间取样植物的块茎在温室中培育的子代植物表现出轻微的 PYVV 感染症状，随着时间的推移消失，表明在该病理系统中出现了恢复和无症状感染表型。混合感染与单一感染中的 PYVV 滴度保持可比性，表明不存在 Potyvirus 对 PYVV 积累的协同/拮抗作用。从受感染的田间取样植物的块茎在温室中培育的子代植物表现出轻微的 PYVV 感染症状，随着时间的推移消失，表明在该病理系统中出现了恢复和无症状感染表型。