A multigene phylogentic analysis of Potato virus Y and its application in strain identification.

The objective of this study is to develop a rapid and accurate multigene phylogenetic analysis to identify Potato virus Y (PVY) strains. The phylogenetic relationships of strains within the PVY species were evaluated with isolate-strain association using five datasets of concatenated sequences from the P1, HC-pro, VPg and CP genes to determine the best dataset for PVY strain identification. Results from phylogenetic analyses and Bayesian tip-association significance (BaTS) tests indicated that the major PVY strains could be distinguished using the P1, VPg and CP concatenated sequences datasets but not the remaining concatenated sequence datasets.

[Comparative analysis of population genetic structure of Potato virus Y from different hosts].

Nucleotide sequences of P3 and pipo genes of Potato virus Y (PVY) from potato and tobacco were compared to investigate the effect of hosts on the population genetic structure. Meanwhile, mutation, natural selection and gene flow were evaluated to determine evolutionary forces responsible for the population genetic dynamics. The fixation indices of population differentiation (FST) of PVY from tobacco and potato were 0.

Anti-TMV activity of malformin A1, a cyclic penta-peptide produced by an endophytic fungus Aspergillus tubingensis FJBJ11.

Plant-associated microorganisms are known to produce a variety of metabolites with novel structures and interesting biological activities. An endophytic fungus FJBJ11, isolated from the plant tissue of Brucea javanica (L.) Merr.

[Sequence variation and protein structure of pipo gene in Potato virus Y].

The objectives of this study were to understand the sequence variation and the putative protein structure of pipo gene in the Potato virus Y (PVY) collected from Solanum tuberosum. The pipo gene in PVY was cloned using a pair of degenerate primers designed from its conserved region and its sequences were used to re-construct phylogenetic tree in Potyvirus genera by a Bayesian inference method. An expected fragment of 235 bp was amplified in all 20 samples by RT-PCR and the pipo genes in the 20 samples assayed shared more than 92% nucleotide sequence similarity with the published sequences of PVY strains.

Complete genome sequence of narcissus late season yellows virus infecting Chinese narcissus in China.

The complete genome sequence of a Chinese narcissus isolate of narcissus late season yellows virus from Zhangzhou, China (NLSYV-ZZ), was determined to be 9,651 nucleotides in length, excluding the 3'-terminal poly (A) tail, by amplification and sequencing of virus RNA. The viral genome contains a single long open reading frame of 9,315 nucleotides encoding a polyprotein of 3,105 amino acids. The polyprotein was predicted to be cleaved into ten mature proteins by three viral proteases.

Expression of rice gall dwarf virus outer coat protein gene (S8) in insect cells.

To obtain the P8 protein of Rice gall dwarf virus (RGDV) with biological activity, its outer coat protein gene S8 was expressed in Spodoptera frugiperda (Sf9) insect cells using the baculovirus expression system. The S8 gene was subcloned into the pFastBac™1 vector, to produce the recombinant baculovirus transfer vector pFB-S8. After transformation, pFB-S8 was introduced into the competent cells (E.

Genetic diversity and population structure of rice stripe virus in China.

Rice stripe virus (RSV) is one of the most economically important pathogens of rice and is repeatedly epidemic in China, Japan and Korea. The most recent outbreak of RSV in eastern China in 2000 caused significant losses and raised serious concerns. In this paper, we provide a genotyping profile of RSV field isolates and describe the population structure of RSV in China, based on the nucleotide sequences of isolates collected from different geographical regions during 1997-2004.