RT Journal Article
SR Electronic
T1 Simultaneous CRISPR/Cas9-mediated editing of cassava <em>eIF4E</em> isoforms <em>nCBP-1</em> and <em>nCBP-2</em> confers elevated resistance to cassava brown streak disease
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 209874
DO 10.1101/209874
A1 Michael A. Gomez
A1 Z. Daniel Lin
A1 Theodore Moll
A1 Collin Luebbert
A1 Raj Deepika Chauhan
A1 Anupama Vijayaraghavan
A1 Renninger Kelley
A1 Getu Beyene
A1 Nigel J. Taylor
A1 J. Carrington
A1 B. Staskawicz
A1 R. Bart
YR 2017
UL http://biorxiv.org/content/early/2017/10/27/209874.abstract
AB Cassava brown streak disease (CBSD) is a major constraint on cassava yields in East and Central Africa and threatens production in West Africa. CBSD is caused by two species of positive sense RNA viruses belonging to the family Potiviridae, genus Ipomovirus: Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). Diseases caused by the family Potyviridae require the interaction of viral genome-linked protein (VPg) and host eukaryotic translation initiation factor 4E (eIF4E) isoforms. Cassava encodes five eIF4E isoforms: eIF4E, eIF(iso)4E-1, eIF(iso)4E-2, novel cap-binding protein-1 (nCBP-1), and nCBP-2. Yeast two-hybrid analysis detected interactions between both CBSV and UCBSV VPg proteins and cassava nCBP-1 and nCBP-2. CRISPR/Cas9-mediated genome editing was employed to generate eif4e, ncbp-1, ncbp-2, and ncbp-1/ncbp-2 mutants in cassava cultivar 60444. Challenge with CBSV showed that ncbp-1/ncbp-2 mutants displayed delayed and attenuated CBSD aerial symptoms, as well as reduced severity and incidence of storage root necrosis. Suppressed disease symptoms were correlated with reduced virus titer in storage roots relative to wild-type controls. However, full resistance to CBSD was not achieved, suggesting that remaining functional eIF4E isoforms may be compensating for the targeted mutagenesis of nCBP-1 and nCBP-2. Future studies will investigate the contribution of these other isoforms to development of CBSD.