My colleague is trying to study the effects of a protein on pathogen inhibition in N. benthamiana. He is expressing it in either a pSITE vector or pCAMBIA1302 that had the GFP gene removed. They are both in GV3101 strain of agrobacteria. His protein is being expressed fine and he got interesting results. However, when he infiltrated just the vectors as controls, the pCAMBIA gave a similar response as his protein but the pSITE did not give any response. A response was not seen in the no infiltration or buffer only conditions. Has anyone else found that the vector backbone alone can alter plant response?