Cassava brown streak viruses

PI: Dr. Stephan Winter

The role of cassava brown streak virus proteins for development of disease and vector transmission is studied taking advantage of infectious virus clones developed at the DSMZ laboratories and cassava genotypes showing differential responses following virus infection. Movement, tissue invasion and replication of viruses in single and mixed infections are central themes of our research. 

Virus and vector elements governing circulative and non-circulative transmission of plant viruses 

PI: Dr. Stephan Winter, Dr. Paolo Margaria

We study the role of virus proteins in vector transmission using infectious virus clones of cassava mosaic viruses, cassava brown streak virus and cucumber vein yellowing virus isolates and strains. In earlier studies, we discovered that particular coat protein mutants of begomoviruses can circulate through the insect while transmission is inhibited and localized circular transmission to particular amino acids moieties in the core region of the virus. 
Using a similar approach, we seek to identify proteins of the non-circulative transmitted ipomoviruses to identify genes critical for virus transmission. The cucumber vein yellowing virus is efficiently transmitted by B. tabaci in contrast to cassava brown streak virus that requires high whitefly numbers for efficient virus transmission and infection. Mutational analysis of CVYV genes will allow identification of virus genes critical for transmission to transfer the knowledge onto cassava brown streak virus. Interaction studies with whitefly proteins will then localize virus receptors critical for non-circulative transmission.