Association of an Alphasatellite with Tomato Yellow Leaf Curl Virus and Ageratum Yellow Vein Virus in Japan Is Suggestive of a Recent Introduction

Abstract

Samples were collected in 2011 from tomato plants exhibiting typical tomato leaf curl disease symptoms in the vicinity of Komae, Japan. PCR mediated amplification, cloning and sequencing of all begomovirus components from two plants from different fields showed the plants to be infected by Tomato yellow leaf curl virus (TYLCV) and Ageratum yellow vein virus (AYVV). Both viruses have previously been shown to be present in Japan, although this is the first identification of AYVV on mainland Japan; the virus previously having been shown to be present on the Okinawa Islands. The plant harboring AYVV was also shown to contain the betasatellite Tomato leaf curl Java betasatellite (ToLCJaB), a satellite not previously shown to be present in Japan. No betasatellite was associated with the TYLCV infected tomato plants analyzed here, consistent with earlier findings for this virus in Japan. Surprisingly both plants were also found to harbor an alphasatellite; no alphasatellites having previously been reported from Japan. The alphasatellite associated with both viruses was shown to be Sida yellow vein China alphasatellite which has previously only been identified in the Yunnan Province of China and Nepal. The results suggest that further begomoviruses, and their associated satellites, are being introduced to Japan. The significance of these findings is discussed.

Molecular Characterization of Betasatellite Associated with Begomovirus on Ageratum conyzoides in Magelang, Central Java

“…Betasatellite associated with ToLJaV has the characteristics of TAATATTAC stem-loop structure, the presence of an ORF along 118 amino acids, and the presence of adenine-rich regions. This result was similar to previous studies by Kon et al (2007) and Shahid et al (2014). These characteristics distinguish betasatellite from other satellites (alphasatellite and deltasatellite).…”

“…Alignment of ORF βC1 with several betasatellite in the Genbank database showed the presence of ORF along 118 amino acids ( Figure 6). This finding similar to the characteristics of betasatellite studied by Kon et al (2007) and Shahid et al (2014).…”

Role of Alphasatellite in Begomoviral Disease Complex

“…The recent advancement and emeiging potential of Next Generation Sequencing approaches will undoubtedly contribute considerably to the elucidation of the aetiology of many of these alphasatellite associated diseases. The fairly recent discovery of alphasatellite in Japan (Shahid et al, 2014) and its presence in papaya gardens in Nepal (Shaliid et al, 2013) suggest that its occurrence and possible role in disease in other agricultural-producing regions need to be investigated. What effect the presence of an alphasatellite and the defective allied component may have on future begomovirus-betasatellite complex is not clear.…”

Requirements for the Packaging of Geminivirus Circular Single-Stranded DNA: Effect of DNA Length and Coat Protein Sequence

“…These Begomoviruses also harbour similar sized cssDNAs of the geminivirus-associated alphasatellites (family Alphasatellitidae, subfamily Geminialphasatellitinae) that are capable of self-replication but are not essential for the progression of the viral disease [10,11]. However, some natural tomato yellow leaf curl virus (TYLCV) plant infections, a Begomovirus that does not require additional components for infectivity, have been shown to harbour both alpha [12] and 2 of 17 beta satellite DNAs [13]. Indeed, both these DNAs can be maintained, and the former can be insect transmitted from artificially inoculated TYLCV plant infections [14,15].…”