Morphogenetic Genes in the T-DNA of Ri Plasmids
Agrobacterium rhizogenes is responsible for the hairy root syndrome of dicotyledonous plants which consists in an abundant proliferation of roots at the wounded site of bacterial infection (Elliot, 1951). Hairy roots contain a portion (T-DNA) of a large bacterial plasmid (Ri plasmid), which directs growth and differentiation of the transformed plant cells (Chilton et al., 1982; Spanò et al-, 1982b; White et al., 1982; Willmitzer et al.,1982). Hairy roots grow very actively in vitro in the absence of hormones with a characteristic highly branched and plagiotropic pattern (David et al., 1984); they synthesize specific opines of which three major types have been so far identified, agropine, mannopine and cucumopine (Petit and Tempe., 1985), corresponding to different families of Ri plasmids (Costantino et al., 1981). Whole, fertile plants of different species have been regenerated from hairy root tissues in several laboratories (Chilton et al., 1982; Spanò et al., 1982a; Tepfer, 1984; Spanò et al., 1987).
KeywordsClarification Agrobacterium Nopaline Octopine
Unable to display preview. Download preview PDF.
- Barbier-Brygoo H, Maurel C., Shen WH, Ephritikhine G, Delbarre A, Guern J, 1990, Use of mutants and transformed plants to study the action of auxins, in: “Hormone perception and signal transduction in animals and plants”, JA Roberts, C Kirk, M Venis, eds, Company of Biologists, Cambridge.Google Scholar
- Cardarelli M., Spanò L, De Paolis A, Mauro ML, Vitali G, Costantino P, Identification of the genetic locus responsible for non-polar root induction by Agrobacterium rhizogenes1855, Plant Mol Biol, 5:385–391.Google Scholar
- Combard A, Brevet J, Borowski D, Cam K, Tempé J, Physical map of the T-DNA region of Agrobacterium rhizogenes strain NCPPB2659, 1987, Plasmid 18:70–75.Google Scholar
- Petit A, Tempé J, The function of T-DNA in nature, 1985, in: “Molecular form and function of the plant genome”, L Van Vloten-Doting, G Groot, T Hall, eds, Plenum Press, New York.Google Scholar
- Spanò L, Costantino P, 1982a, Regeneration of plants from callus cultures of roots induced by Agrobacterium rhizogenes on tobacco, Z Pflanzenphysiol, 106.87–92.Google Scholar