Rhizobial Lipo-oligosaccharide Signals and Their Role in Plant Morphogenesis; Are Analogous Lipophilic ChitinDerivatives Produced by the Plant?

Rhizobia, bacterial symbionts of leguminous plants, produce lipo-oligosaccharide signal molecules after induction of their nod genes by the plant host. The effects of these signals on plant developmental processes are discussed. Considering the similarity of the lipo-oligosaccharides with chitin, we discuss the possible basis of these effects and show some preliminary results which indicate that analogous molecules could occur in uninfected plants.