Intrusive growth - The plant analog of dendrite and axon growth in animals

Abstract

In all the cases of invasion of cell extensions described here, the old part of the cell remains in position while new parts grow to new locations. Therefore, although plant cells do not migrate as in animal cells, cell parts do reach new locations as occurs with axons and dendrites. The common view that plant cells do not migrate at all is therefore inadequate. Certain parasitic vascular plants, such as Viscum spp., Loranthus spp. and Orobanche spp., invade host plants without inducing their defense mechanisms to such an extent that they block the invasion. Similarly, mutualistic symbioses such as ectomycorrhizas and endomycorrhizas do not induce wounding responses. Could the mechanisms of invasion of such parasites and symbionts be genetic modifications of mechanisms normally controlling the fibre, sclereid and laticifer differentiation used for parasitic and symbiotic interactions?