Basic Proteins Produced by Hairy Root Cultures of Trichosanthes kirilowii var. japonica

Abstract

Hairy root cultures of Trichosanthes kirilowii var. japonica (Cucurbitaceae) were established by direct inoculation of Agrobacterium rhizogenes ATCC15834 on sterile seedlings. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot analysis of intracellular proteins showed that karasurins, ribosome-inactivating proteins (RIPs) in root tubers of T. kirilowii var. japonica, were not accumulated in the hairy roots. A major basic protein produced by the hairy roots was tentatively identified as a class III chitinase based on N-terminal amino acid sequence homology comparisons. In spite of the apparent lack of karasurins, the basic protein fraction from the hairy roots exhibited ribosome-inactivating activity in the rabbit reticulocyte system, suggesting the presence of RIPs in the hairy roots.