Molecular characterization of tomato leaf curl Joydebpur virus and tomato leaf curl New Delhi virus associated with severe leaf curl symptoms of papaya in Bangladesh

Authors: HAMIM, ISLAM - Bangladesh Agricultural University; BORTH, WAYNE - University Of Hawaii; Suzuki, Jon; MELZER, MICHAEL - University Of Hawaii; Wall, Marisa; HU, JOHN - University Of Hawaii

Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2020
Publication Date: 8/7/2020
Citation: Hamim, I., Borth, W., Suzuki, J.Y., Melzer, M., Wall, M.M., Hu, J.S. 2020. Molecular characterization of tomato leaf curl Joydebpur virus and tomato leaf curl New Delhi virus associated with severe leaf curl symptoms of papaya in Bangladesh. European Journal of Plant Pathology. 158:457-472. https://doi.org/10.1007/s10658-020-02086-7.
DOI: https://doi.org/10.1007/s10658-020-02086-7

Interpretive Summary: Papaya cultivation in Bangladesh is hindered by the widespread infection by papaya ringspot virus (PRSV) that belongs to a group of plant viruses known as potyviruses. However, leaf curl diseases in papaya caused by infection by viruses from another group of viruses known as begomoviruses are increasing, due to the wide host range of these viruses and the insects that carry them, as well as the practice of mixed cropping or the planting of different crops in the same field. Based on genome sequence of the complete as well as satellite components of a virus infecting papaya in Bangladesh, it was determined that this virus was a variant of and probably evolved from a genetic mix of different strains of the tomato leaf curl Joydebpur virus, a begomovirus previously identified infecting tomato in India and Bangladesh as well as infecting chili in India. Similarly, genomic sequences of another begomovirus, known as tomato leaf curl New Delhi virus or ToLCNDV also previously identified in tomato was identified in papaya with viral symptoms in Bangladesh. The findings in this and previous studies suggest the existence of multiple begomoviruses including ToLCJoV, ToLCNDV and a previously characterized begomovirus known as tomato leaf curl Bangladesh virus (ToLCBV) causing severe leaf curl disease of papaya in Bangladesh and a serious threat to the country’s papaya industry.

Technical Abstract: A survey of viruses in papaya plants exhibiting leaf curl symptoms in Bangladesh showed the occurrence of three begomoviruses: tomato leaf curl Joydebpur virus (ToLCJoV) and its betasatellite (ToLCJoB), tomato leaf curl New Dehli virus (ToLCNDV), and tomato leaf curl Bangladesh virus (ToLCBV). The full-length genome of ToLCJoV (MT127782) was determined and shown to be closely related to ToLCJoV isolates from tomato in Bangladesh or India and chili in India. ToLCJoV from papaya was a recombinant of a ToLCJoV isolate from mungbean in India or an unknown host and another ToLCJoV isolate from tomato in Bangladesh. ToLCJoV betasatellite from papaya (MT161673) showed the highest identity to ToLCJoB from tomato in Bangladesh and chili in India. ToLCJoB from papaya is a recombinant of a ToLCJoB from chili in India and an unknown ToLCJoB. The ToLCNDV DNA-A (MT161674) and DNA-B (MT161675) from papaya are closely related to ToLCNDV isolates from tomato in Bangladesh. The ToLCNDV-papaya DNA-B was a recombinant molecule. Of the 45 papaya leaf samples with leaf curl symptoms, 29 tested positive for ToLCBV, 10 for ToLCJoV and four for ToLCNDV. Our findings documented multiple begomoviruses in papaya exhibiting leaf curl disease in Bangladesh and suggested several recombination events and a host shift from tomato to papaya.