Substrate utilization by embryogenic and non embryogenic cell suspension cultures of cucumis sativus l
De Cat W.
Journal of Plant Physiology 127(3-4): 271-280
Sucrose utilization by a non-embryonic cell suspension culture of cucumber proceeded by extracellular hydrolysis. The glucose moiety was used first, while fructose was only utilized when the medium was nearly depleted of glucose. This preferential utilization of glucose was also observed when the cells were grown on glucose + fructose, but not on glucose + galactose. Lactose supported growth of the non-embryogenic culture as well as sucrose, but was not hydrolysed extracellularly. In contrast, an embryogenic culture hydrolysed sucrose extracellularly, but did not show the perferential utilization of glucose in the presence of fructose. Also, the embryogenic culture did not metabolize lactose. As both cell types contained a comparable .beta.-galactosidase activity, the lack of growth of the embryogenic cells on lactose can be explained by lack of a specific lactose carrier.