A putative transcriptional coactivator KELP of Arabidopsis thaliana and its homolog of Brassica campestris
(BcKELP) can bind the movement protein (MP) of Tomato mosaic virus (ToMV) in vitro and, when transiently
over-expressed, interfere with the cell-to-cell movement of ToMV. In this study, we generated and
selected transgenic Nicotiana tabacum lines expressing BcKELP constitutively and examined their resistance
to ToMV. We also investigated changes in MP localization in initially infected Nicotiana benthamiana
cells expressing BcKELP transiently. Our results indicate that a high expression of BcKELP can
reduce viral initial and short-distance movement probably through disturbance of plasmodesmal targeting
of MP.