JAX1-MEDIATED RESISTANCE TO PLANT VIRUS
Plants resist pathogen infection with a multilayered defense strategy. Lectins are believed to serve as defensive molecules, but their precise roles have remained unclear. Yamaji et al. (pages 778–793) cloned the novel virus-resistance gene JAX1 from Arabidopsis thaliana, which encodes a lectin-like protein with similarity to another virus-resistance protein, RTM1. However, JAX1-mediated resistance differs from other well-characterized virus-resistance machineries such as R gene-mediated resistance involving hypersensitive responses or RNA silencing. Whereas RTM1 functions to inhibit viral long-distance movement, JAX1 inhibits viral proliferation at the cellular level. The characterization of JAX1-mediated resistance demonstrates the generality and significance of lectin-mediated resistance to plant viruses. The cover displays the systemic spread of green fluorescent protein fluorescence monitoring virus infection in a wild-type plant (bottom) and strict inhibition of virus infection in a JAX1-expressing transgenic plant (top).