First report of two distinct badnaviruses associated with Bougainvillea spectabilis in India

Abstract

Two distinct types of symptoms, severe yellow mosaic and chlorotic vein-banding, were observed on Bougainvillea spectabilis at two different locations in India. Electron microscopy revealed bacilliform virus particles in leaf samples from both places. PCR amplification, cloning, sequencing and sequence analysis of reverse transcriptase and ribonuclease H coding region in open reading frame 3 indicated that two distinct badnaviruses are associated with B. spectabilis in India.Keywords Badnavirus Á Bougainvillea spectabilis Á Delhi Á Tirupati Á PCR Bougainvillea spectabilis Willd (flower paper) is a widely grown ornamental plant in India. During 2008, B. spectabilis plants developed distinct severe yellow mosaic (SYM) in parts of Tirupati (Fig. 1a). Subsequently in 2009, a chlorotic vein-banding (CVB) was noticed on leaves of B. spectabilis on the campus of the Indian Agricultural Research Institute, New Delhi (Fig. 1b). Leaf dip electron microscopy of symptomatic bougainvillea leaves revealed the association of bacilliform virus particles measuring 120-150 nm 9 20 nm (Fig. 2). Previously, bacilliform virus particles have been shown to be associated with bougainvillea plants with CVB in Brazil (Rivas et al. 2005) and mottling, chlorosis, vein-banding and stunting in Taiwan (Tsai et al. 2005).To confirm the virus identity, symptomatic leaves of bougainvillea collected from Tirupati and Delhi were subjected to polymerase chain reaction (PCR) amplification using two degenerate Badnavirus primers viz. BadnaFP (5 0 ATGCCITTYGGIAARAAYGCICC3 0 ) and BadnaRP (5 0 CCAYTTRCAIACISCICCCCAICC3 0 ) corresponding to putative ribonuclease H (RNase H) and reverse transcriptase (RT) coding regions (Yang et al. 2003). Both samples yielded an amplicon of approximately 600 bp, and no amplification was observed in healthy, symptomless bougainvillea (Fig. 3). The amplicons were cloned in pGEM-T easy vector (Promega, Madison, WI, USA) and sequenced. BLAST analysis of the 577 bp of RNase H and RT nucleotide sequences of viral DNA from bougainvillea with SYM symptoms from Tirupati (accession GQ254410) had maximum sequence identity of 73% in open reading frame 3 (ORF 3) of Bougainvillea spectabilis chlorotic vein-banding virus (BsCVBV) (accessions EU034539, DQ347841, and DQ103759). An identical sequence size of amplified viral DNA isolated from bougainvillea with CVB symptoms from Delhi (accession GQ254411) had 72% sequence identity with the sequences of same three BsCVBV isolates. Nucleotide and amino acid sequences of putative RT and RNase H region of ORF 3 of these two badnaviruses were analyzed using Bio Edit version 7.0.4 for sequence identities with other badnaviruses. The two badnaviruses infecting bougainvillea in India shared an identity of 76.2% in nucleotide and 88.6% in amino acid sequences with each other. Comparison of nucleotide and amino acid sequences of badnaviruses infecting bougainvillea from India and Taiwan showed identities in the range of 72.3-73.5% for nucleotides and 83.4-84.9% in amino acids of RT and RNase H. Be...

Genetic Diversity of Badnaviruses Associated with Bougainvillea in Brazil

“…As a monophyletic group formed by Brazilian isolates 25(02), 28(02), 35(01) and Delhi, India (GQ254411), isolate was supported by 100% bootstrap, they can be considered the same species, as proposed by Baranwal et al. (). The authors also suggested a new species called Tirupati, which was not found in the samples tested in this study.…”

“…In a previous study, Baranwal et al. () also reported diversity in nucleotide sequences of badnaviruses in bougainvillea from two different geographical regions of India (Delhi and Tirupati). Based on the nucleotide sequence identity within the RT/RNase H, whose value was lower than 80% (King et al.…”

“…Yamashita et al 2004 described a Badnavirus from B. glabra with chlorotic spot and mild mosaic from SP, Brazil. A similar disease was described in Taiwan (Tsai et al 2008) and India (Baranwal et al 2010). Tsai et al (2008) proposed the name Bougainvillea spectabilis chlorotic vein-banding virus (BsCVBV), and the name Bougainvillea chlorotic vein banding virus (BCVBV) was accepted as definitive by International Committee on Taxonomy of Viruses (ICTV 2013).…”

“…Although the method is a pathway for viruses to spread, these pathogens have been rarely reported. The literature reports the occurrence of the Impatiens necrotic spot virus (INSV) in Iran (Shahraeen et al 2002), a Badnavirus in Brazil, Taiwan and India (Rivas et al 2005;Tsai et al 2008;Baranwal et al 2010), and one unclassified Begomovirus in India (GenBank accession JQ 693136).…”

“…In Brazil, besides BCVBV, Sugarcane bacilliform virus and Banana streak virus (Vega and Sordi 1991;Brioso et al 2000;Rivas et al 2005), two unidentified badnaviruses, have been reported in Yucca elephantipes and Schefflera sp., associated with chlorotic rings, (Rivas et al 1994;Brioso et al 2003). Studies have been conducted to investigate the diversity of Badnavirus sequences (Yang et al 2003;Eni et al 2008;Baranwal et al 2010;Oro et al 2012;Sether et al 2012;Borah et al 2013;Karuppaiah et al 2013). However, the information on recombination analyses for this particular species still remains scarce (Bousalem et al 2009;Rao et al 2014).…”