Studies on selection and characterization of a stress-tolerant sugarcane cell line

A sugarcane (Saccharum sinensis Roxb.) cell line R932 resistant to growth inhibition by the proline analogue hydroxyproline was selected. R932 showed greater tolerance to PEG and low temperature stress than the donor. The line R932 showed larger accumulation of proline (x3.2) than the sensitive donor. In vitro enzymic analysis of gamma-glutamyl kinase involved in the proline biosynthesis showed that the enzyme in the R932 was less sensitive to inhibition by 50-mM exogenous proline than that in the donor. The results suggested that the change in gamma-glutamyl kinase properties might lead to excessive accumulation of proline, and the elevated proline contents might in turn lead to an increase in tolerance to environmental stress.