Molecular Characterization of a Begomovirus, α-Satellite, and ß-Satellite Associated with Leaf Curl Disease of Parthenium hysterophorus in India.

ABSTRACT

Parthenium hysterophorus plants exhibiting severe leaf curl and stunting symptoms were observed near agriculture fields in Lucknow, India. The association of a begomovirus, ß-satellite, and α-satellite with these symptoms of a Parthenium disease was investigated by sequence analyses of virus and satellite DNA amplified by rolling circle amplification and polymerase chain reaction. The highest sequence identities and closest phylogenetic relationships for the begomovirus, ß-satellite, and α-satellite detected in P. hysterophorus plants were to Tomato leaf curl virus (ToLCV), papaya leaf curl ß-satellite (PaLCuB), and Ageratum yellow vein India α-satellite (AYVIA), respectively. These findings identified the virus and satellites infecting the Parthenium sp. as ToLCV, PaLCuB, and AYVIA, respectively. P. hysterophorus and tomato seedlings infected with cloned ToLCV, PaLCuB, and AYVIA by agroinoculation developed leaf curl symptoms, whereas plants infected with ToLCV alone or with ToLCV and AYVIA developed mild yellowing. The results show that this complex infects and causes disease in P. hysterophorus and tomato. P. hysterophorus is an invasive weed commonly found around agricultural fields and along roadsides in India. These results indicate that P. hysterophorus plants infected with ToLCV and associated satellite DNA act as an alternate host (reservoir), and that could lead to increased incidence of tomato leaf curl disease.