A new putative plasmodesmata-associated protein, At1g19190, in Arabidopsis

Plasmodesmata are channels that traverse cell walls to establish a symplastic continuum through whole plants. A plasmodesmal-associated protein, AtRGP2, is delivered to the plasmodesmata via the Golgi apparatus. In this paper, GFP:At1g19190 fusion protein was constructed and compared to AtRGP2:YFP. GFP:At1g19190 displays fluorescence patterns along the cell periphery and in a punctate pattern that co-localizes with aniline blue-stained callose. Cytoskeleton disturbance drugs were used to treat transgenic GFP:At1g19190 Arabidopsis seedlings. Colchicine, which disturbs the microtubule network, was found capable of disturbing the localization of At1g19190, but cytochalasin B (CB) and brefeldin A (BFA) did not affect the localization of At1g19190. Micrografting methods revealed that the transfer of GFP:At1g19190 fluorescence from transgenic Arabidopsis to non-fluorescent wild-type was absent during AtRGP2 grafting. At1g19190 appeared to be a potentially important protein in the plasmodesmata (Pd) structure and may play a critical role in substance transport, although its exact mechanism is still unknown. Key words: Plasmodesmata, AtRGP2, At1g19190, cytoskeleton, micrografting.