Ageratum yellow vein China virus is a distinct begomovirus species associated with a DNA beta molecule

作者：Xiong, Qing; Fan, Sanwei; Wu, Jianxiang; Zhou, Xueping^*

来源：Phytopathology, 2007, 97(4): 405-411.

DOI：10.1094/PHYTO-97-4-0405

• WHITEFLY-TRANSMITTED GEMINIVIRUSES
• CURL-YUNNAN-VIRUS
• MONOPARTITE BEGOMOVIRUSES
• MOSAIC DISEASE
• BINDING MOTIF
• PLANT-CELLS
• PROTEIN
• SATELLITE
• TOBACCO
• IDENTIFICATION

Ageratum conyzoides plants exhibiting yellow vein symptoms, collected near Haikou, Hainan Province, China, contained begomoviral DNA-A-like molecules. The complete sequences of the molecules from two samples, Hn2 and Hn2-19, were shown to consist of 2,768 and 2,748 nucelotides (m), respectively. These sequences have more than 97% nucleotide sequence identity, but less than 86% identity with other reported begomovirus sequences. In line with the taxonomic convention for begomoviruses, Hn2 and Hn2-19 are therefore considered to represent isolates of a distinct begomovirus species, for which the name Ageratum yellow vein China virus (AYVCNV) is proposed. Sequence alignment shows AYVCNV has arisen by recombination among viruses related to Ageratum yellow vein virus, Papaya leaf curl China virus, and an unidentified begomovirus. Southern blot analyses revealed that all plants sampled contained molecules resembling DNA beta. DNA beta molecules from three samples were 1,323 or 1,324 nt long and had > 98% sequence identity but < 81% identity with previously reported DNA beta sequences. Infectious clones of Hn2 and its associated DNA beta were constructed and agroinoculated to plants. Hn2 alone caused sporadic asymptomatic systemic infection of Nicotiana benthamiano, N. glutinosa, Lycopersicon esculentum, Petunia hybrida, and A. conyzoides but its accumulation was much enhanced in plants co-inoculated with DNA beta. The co-inoculated N. benthaimana, N. glutinosa, P. hybrida, and L. esculentum plants developed leaf curling or leaf crinkling symptom; those in A. conyzoides were typical of ageratum yellow vein disease. When the DNA beta molecules associated with four other Chinese begomoviruses were coinoculated with Hn2 to N. benthamiana and N. glutinosa, the DNA beta molecules were replicated, and the plants developed systemic symptoms of types that were specific for each DNA beta. This illustrates that there is less specific interaction between monopartite begomovirus and DNA beta than between the DNA-A and DNA-B of begomoviruses with bipartite genomes.

• 出版日期2007-4
• 单位浙江大学