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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Plant Genetic Resources and Disease Research » Research » Publications at this Location » Publication #392578

Research Project: Management, Characterization, and Evaluation of Pacific Tropical and Subtropical Fruit and Nut Genetic Resources and Associated Information

Location: Tropical Plant Genetic Resources and Disease Research

Title: Survey of viruses infecting Basella alba in Hawaii

Author
item WANG, XUPENG - University Of Hawaii
item LARREA-SARMIENTO, ANDREW - University Of Hawaii
item OLMEDO-VELARDE, ALEJANDRO - University Of Hawaii
item AL RWAHNIH, MAHER - University Of California, Davis
item BORTH, WAYNE - University Of Hawaii
item Suzuki, Jon
item Wall, Marisa
item MELZER, MICHAEL - University Of Hawaii
item HU, JOHN - University Of Hawaii

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary: Malabar spinach leaves with virus infection-like symptoms were found in a community garden on the island of Oahu, Hawaii in 2018. Using antibody- as well as polymerase chain reaction (PCR)-based detection methods, researchers identified the plant RNA virus, basella rugose mosaic virus (BaRMV) in symptomatic plants. A more comprehensive analysis of Malabar spinach with virus infection-like symptoms from three different locations using modern sequencing methods identified not only BaRMV, but additional RNA viruses including chilli veinal mottle virus (ChiVMV), alternanthera mosaic virus (AltMV), basella alba endornavirus (BaEV), broad bean wilt virus 2 (BBWV2), and a so-called viroid, Iresine viroid 1 (IrVd-1), an RNA-based, virus-like element. Additional malabar spinach samples from the community gardens were examined to determine the incidence, distribution, and diversity of these viruses and the viroid. Of 63 samples, 21 were positive for BaRMV, 57 were positive for ChiVMV, 21 were positive for AltMV, 19 were positive for BaEV, and 14 were positive for BBWV2.

Technical Abstract: Malabar spinach (Basella alba, Basellaceae) with leaves exhibiting symptoms of mosaic, rugosity, and malformation were found in a community garden on Oahu, Hawaii, in 2018. Preliminary studies using ELISA and RT-PCR identified basella rugose mosaic virus (BaRMV) in symptomatic plants. BLASTx and BLASTn analyses of RT-PCR product sequences from Malabar spinach samples growing in different community gardens suggested the presence of additional potyviruses. High-throughput sequencing (HTS) analysis was conducted on ribosomal RNA-depleted composite RNA samples of potyvirus-positive plants from three locations. About 40 million single-end reads were generated and 72,959 contigs were obtained after quality control, trimming, and de novo assembly operations. Contig annotation revealed variously-sized contigs with sequence similarities to BaRMV, chilli veinal mottle virus (ChiVMV), alternanthera mosaic virus (AltMV), basella alba endornavirus (BaEV), broad bean wilt virus 2 (BBWV2), and Iresine viroid 1 (IrVd-1). Virus- and viroid-specific primers were designed based on HTS sequencing results and used in RT-PCR and Sanger sequencing to confirm the presence of these viruses and the viroid. Additional B. alba samples from the community gardens were examined to determine the incidence, distribution, and diversity of these viruses and the viroid. Of 63 samples, 21 were positive for BaRMV, 57 were positive for ChiVMV, 21 were positive for AltMV, 19 were positive for BaEV, and 14 were positive for BBWV2.