Molecular studies on the interactions between African cassava mosaic virus (ACMV) and East African cassava mosaic virus (EACMV UG) infecting cassava (Manihot esculenta Crantz) African cassava mosaic virus East African cassava mosaic virus Uganda mixed infection synergism tissue tropisms AC2 AC4 gene silencing suppression agroinfiltration quantitative PCR GFP fluorescence transient gene expression. Mischinfektion Synergismus Gewebeausbreitung post transkriptionales Gene silencing PTGS transiente Genexpression GFP Fluoreszenz Agroinfiltration quantitative PCR