Involvement of RDR6 in short-range intercellular RNA silencing in Nicotiana benthamiana.
Qin C., Shi N., Gu M., Zhang H., Li B., Shen J., Mohammed A., Ryabov E., Li C., Wang H., Liu Y., Osman T., Vatish M., Hong Y.
In plants, non-cell autonomous RNA silencing spreads between cells and over long distances. Recent work has revealed insight on the genetic and molecular components essential for cell-to-cell movement of RNA silencing in Arabidopsis. Using a local RNA silencing assay, we report on a distinct mechanism that may govern the short-range (6-10 cell) trafficking of virus-induced RNA silencing from epidermal to neighbouring palisade and spongy parenchyma cells in Nicotiana benthamiana. This process involves a previously unrecognised function of the RNA-dependent RNA polymerase 6 (RDR6) gene. Our data suggest that plants may have evolved distinct genetic controls in intercellular RNA silencing among different types of cells.