Two novel DNAs that enhance symptoms and overcome CMD2 resistance to cassava mosaic disease

Show simple item record Ndunguru, J. De León, L. Doyle, C.D. Sseruwagi, P. Plata, G. Legg, J.P. Thompson, G. Tohme, J. Aveling, T.A.S. (Terry) Ascencio-Ibáñez, J.T. Hanley-Bowdoin, L. 2016-05-12T11:54:08Z 2016-05-12T11:54:08Z 2016-04
dc.description.abstract Cassava mosaic begomoviruses (CMBs) cause cassava mosaic disease (CMD) across Africa and the Indian subcontinent. Like all members of the geminivirus family, CMBs have small, circular single-stranded DNA genomes. We report here the discovery of two novel DNA sequences, designated SEGS-1 and SEGS-2 (for sequences enhancing geminivirus symptoms), that enhance symptoms and break resistance to CMD. The SEGS are characterized by GC-rich regions and the absence of long open reading frames. Both SEGS enhanced CMD symptoms in cassava (Manihot esculenta Crantz) when coinoculated with African cassava mosaic virus (ACMV), East African cassava mosaic Cameroon virus (EACMCV), or East African cassava mosaic virus-Uganda (EACMV-UG). SEGS-1 also overcame resistance of a cassava landrace carrying the CMD2 resistance locus when coinoculated with EACMV-UG. Episomal forms of both SEGS were detected in CMB-infected cassava but not in healthy cassava. SEGS-2 episomes were also found in virions and whiteflies. SEGS-1 has no homology to geminiviruses or their associated satellites, but the cassava genome contains a sequence that is 99% identical to full-length SEGS-1. The cassava genome also includes three sequences with 84 to 89% identity to SEGS-2 that together encompass all of SEGS-2 except for a 52-bp region, which includes the episomal junction and a 26-bp sequence related to alphasatellite replication origins. These results suggest that SEGS-1 is derived from the cassava genome and facilitates CMB infection as an integrated copy and/or an episome, while SEGS-2 was originally from the cassava genome but now is encapsidated into virions and transmitted as an episome by whiteflies. en_ZA
dc.description.department Microbiology and Plant Pathology en_ZA
dc.description.librarian hb2016 en_ZA
dc.description.sponsorship This study was funded by a grant (DBI-1110050) to L.H.-B. and J.N. from the BREAD program of the U.S. National Science Foundation and by grants from the Bill & Melinda Gates Foundation and the U.K. Department for International Development (DFID). J.N. was supported by a graduate fellowship from the International Institute of Tropical Agriculture (IITA) and by the Donald Danforth Plant Science Center. L.D.L. was supported by a Fulbright Fellowship. IITA also supported the sample collection in Tanzania through a subgrant to the Mikocheni Agricultural Research Institute. National Science Foundation (NSF) provided funding to Linda Hanley- Bowdoin under grant number DBI-1110050. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Ndunguru, J, De León, L, Doyle, CD, Sseruwagi, P, Plata, G, Legg, JP, Thompson, G, Tohme, J, Aveling, T, Ascencio-Ibáñez, JT & Hanley-Bowdoin, L 2016, 'Two novel DNAs that enhance symptoms and overcome CMD2 resistance to cassava mosaic disease', Journal of Virology, vol. 90, n. 8, pp. 4160-4173. en_ZA
dc.identifier.issn 0022-538X (print)
dc.identifier.other 1098-5514 (online)
dc.identifier.other 10.1128/JVI.02834-15
dc.language.iso en en_ZA
dc.publisher American Society for Microbiology en_ZA
dc.rights © 2016 Ndunguru et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. en_ZA
dc.subject Resistance en_ZA
dc.subject Cassava mosaic begomoviruses (CMBs) en_ZA
dc.subject Cassava mosaic disease (CMD) en_ZA
dc.subject DNA sequences en_ZA
dc.title Two novel DNAs that enhance symptoms and overcome CMD2 resistance to cassava mosaic disease en_ZA
dc.type Article en_ZA

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