Replication promiscuity of DNA-β satellites associated with monopartite begomoviruses; deletion mutagenesis of the Ageratum yellow vein virus DNA-β satellite localizes sequences involved in replication

Abstract

Pseudorecombination studies inNicotiana benthamianademonstrate thatAgeratumyellow vein virus (AYVV) andEupatoriumyellow vein virus (EpYVV) can functionally interact with DNA-βsatellites associated with AYVV, EpYVV, cotton leaf curl Multan virus (CLCuMV) and honeysuckle yellow vein virus (HYVV). In contrast, CLCuMV shows some specificity in its ability to interact with distinct satellites and HYVV is able to interact only with its own satellite. Using anN. benthamianaleaf disk assay, we have demonstrated that HYVV is unable totrans-replicate other satellites. To investigate the basis oftrans-replication compatibility, deletion mutagenesis of AYVV DNA-βhas been used to localize the origin of replication to approximately 360 nt, encompassing the ubiquitous nonanucleotide/stem–loop structure, satellite conserved region (SCR) and part of the intergenic region immediately upstream of the SCR. Additional deletions within this intergenic region have identified a region that is essential for replication. The capacity for DNA-βsatellites to functionally interact with distinct geminivirus species and its implications for disease diversification are discussed.