GROWTH OF TOBACCO PROTOPLASTS STIMULATED BY SYNTHETIC LIPO-CHITOOLIGOSACCHARIDES

Nodulation (Nod) factors are lipo-chitooligosaccharides (LCOs) secrete d by rhizobia to trigger the early steps of nodule organogenesis in le guminous plants. A method to synthesize LCOs in vitro was developed. S ynthetic LCOs alleviated the requirement for auxin and cytokinin to su stain growth of cultured tobacco protoplasts. LCOs containing C-18:1 t rans-fatty acyl substituents were more effective than those containing cis-fatty acids in promoting cell division as well as in activating a n auxin-responsive promoter and the expression of a gene implicated in auxin action. These data indicate that LCOs redirect plant growth als o in nonlegumes by activating developmental pathways also targeted by phytohormones.