The plant DNA virus African cassava mosaic virus (ACMV) is believed to replicate by a rolling circle mechanism. To investigate complementary-sense DNA (lagging strand) synthesis, we have analysed the heterogenous form of complementary-sense DNA (H3 DNA) from infected Nicotiana benthamiana by two-dimensional agarose gel electrophoresis and blot hybridisation. The presence of an RNA moeity is dem...

The resistance/susceptibility of 5 cassava cultivars from Ghana to infectious clones of two cassava mosaic viruses (ACMV-[CM] and EACMV/ACMV-[CM]) was investigated in this study. Plantlets of cassava cultivars were obtained using nodal cuttings initiated from tissue culture. These cassava cultivars were challenged with both DNA A and B components of the infectious clones named above using parti...

Gene silencing mediated by double-stranded RNA is a sequence-specific RNA degradation mechanism highly conserved in eukaryotes that serves as an antiviral defense pathway in both plants and Drosophila. Short interfering RNAs (siRNAs), the 21- to 23-nt double-stranded intermediates of this natural defense mechanism, are becoming powerful tools for reducing gene expression and countering viral in...

Mitigation of cassava mosaic disease (CMD) focuses on the introgression of resistance imparted by the polygenic recessive (CMD1), dominant monogenic (CMD2) and CMD3 loci. The mechanism(s) of resistance they impart, however, remain unknown. Two CMD susceptible and nine CMD resistant cassava genotypes were inoculated by microparticle bombardment with infectious clones of African cassava mosaic vi...

Cassava (Manihot esculenta Crantz) is an important crop that constitutes staple food and income for 800 million people worldwide. yield in Côte d'Ivoire reduced due to a variety of factors, including cassava mosaic disease. Despite the impact pathogen Mosaic Virus (CMV) on production, genetic diversity this virus rarely studied d'Ivoire. This study aims assess molecular variabilit...

The origin of replication of African cassava mosaic virus (ACMV) and a gene expression vector based on Potato virus X were exploited to devise an in planta system for functional analysis of the geminivirus replication-associated protein (Rep) in transgenic Nicotiana benthamiana line pOri-2. This line contains an integrated copy of a tandem repeat of the ACMV origin of replication flanking nonvi...

The products of three open reading frames encoded by the bipartite geminiviruses have been implicated in viral spread: AC2, BV1 and BC1. Alignment of the DNA B encoded gene products, BV1 and BC1, from African cassava mosaic virus (ACMV) with six other bipartite geminiviruses showed several highly conserved regions. Specific amino acids were selected for mutagenic studies to ascertain the tolera...