MONOCOTYLEDONOUS PLANTS AS HOSTS FOR AGROBACTERIUM

Fifteen species from nine monocotyledonous families were inoculated with strains of Agrobacterium tumefaciens, A. rhizogenes, and A. rubi. Tumor production was observed in seven of these species: Arthropodium cirratum (New Zealand rock lily), Cordyline australis (New Zealand cabbage tree), Dioscorea bulbifera (yam), Monstera deliciosa (fruit salad plant), Nerine bowdenii, Polygonatum x hybridum (Solomon's seal), and Zantedeschia aethiopica (arum lily). The use of appropriate controls for Agrobacterium inoculations and the detection of opines in extracts from most of these tumors confirmed that they had resulted from Agrobacterium-mediated gene transfer. Chlorophyll retention around tumors during senescence in some of the plant species was attributed to the expression of the T-DNA isopentyl-transferase gene. We conclude that more monocotyledons are hosts for Agrobacterium transformation than previously thought. Important factors for the induction of tumors included the choice of Agrobacterium strain, the growth phase of the plant, and the organ being inoculated.