MED-Mediterranean Institute for Agriculture, Environment and Development, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal.
Information and Computational Science Department, The James Hutton Institute, Dundee DD2 5DA, UK.
Viruses. 2021 Oct 9;13(10):2035. doi: 10.3390/v13102035.
Olea europaea Geminivirus (OEGV) was recently identified in olive in Italy through HTS. In this work, we used HTS to show the presence of an OEGV isolate in Portuguese olive trees and suggest the evolution direction of OEGV. The bipartite genome (DNA-A and DNA-B) of the OEGV-PT is similar to Old World begomoviruses in length, but it lacks a pre-coat protein (AV2), which is a typical feature of New World begomoviruses (NW). DNA-A genome organization is closer to NW, containing four ORFs; three in complementary-sense AC1/Rep, AC2/TrAP, AC3/REn and one in virion-sense AV1/CP, but no AC4, typical of begomoviruses. DNA-B comprises two ORFs; MP in virion sense with higher similarity to the tyrosine phosphorylation site of NW, but in opposite sense to begomoviruses; BC1, with no known conserved domains in the complementary sense and no NSP typical of bipartite begomoviruses. Our results show that OEGV presents the longest common region among the begomoviruses, and the TATA box and four replication-associated iterons in a completely new arrangement. We propose two new putative conserved regions for the geminiviruses CP. Lastly, we highlight unique features that may represent a new evolutionary direction for geminiviruses and suggest that OEGV-PT evolution may have occurred from an ancient OW monopartite that lost V2 and C4, gaining functions on cell-to-cell movement by acquiring a DNA-B component.
油橄榄双生病毒（Olea europaea Geminivirus，OEGV）最近在意大利的橄榄中通过高通量测序（HTS）被鉴定出来。在这项工作中，我们使用 HTS 显示了 OEGV 分离株在葡萄牙橄榄树上的存在，并提出了 OEGV 的进化方向。OEGV-PT 的二分体基因组（DNA-A 和 DNA-B）在长度上与旧世界伴生病毒相似，但它缺乏一个前壳蛋白（AV2），这是新世界伴生病毒（NW）的典型特征。DNA-A 基因组组织更接近 NW，包含四个 ORF；三个在互补 sense 的 AC1/Rep、AC2/TrAP、AC3/REn，一个在病毒 sense 的 AV1/CP，但没有 AC4，这是伴生病毒的典型特征。DNA-B 包含两个 ORF；MP 在病毒 sense 上与 NW 的酪氨酸磷酸化位点具有更高的相似性，但与伴生病毒相反 sense；BC1 在互补 sense 上没有已知的保守结构域，也没有双分体伴生病毒的 NSP。我们的结果表明，OEGV 在伴生病毒中具有最长的共同区域，TATA 盒和四个复制相关的串联重复在一个全新的排列中。我们提出了两个新的 geminiviruses CP 可能的保守区域。最后，我们强调了可能代表 geminiviruses 新进化方向的独特特征，并提出 OEGV-PT 的进化可能是从古老的 OW 单分体丢失 V2 和 C4 开始的，通过获得 DNA-B 成分获得细胞间运动的功能而发生的。
