[Activation of cell division in the quiescent center of excised maize root tip].

The phenomenon of activation of cell proliferation in the quiescent center of excised maize roots is described. The root tips were grown on wet filter paper in Petri dishes. This phenomenon was observed in 8 to 14 maize cultivars and was absent in excised Arabidopsis root tips.

Proton pumping in growing part of maize root: its correlation with 14-3-3 protein content and changes in response to osmotic stress.

The spatial pattern of mitotic activity, cell elongation, rate of H+ fluxes, and 14-3-3 protein content were determined in Zea mays roots. We found that the regions along the apical part of the growing root conversely differ in their proton pumping activity. Higher rate of H+ efflux coincides with higher growth rate and correlates with increased 14-3-3 protein content in membrane preparations.

Physiochemical properties of the Vi antigen before and after mild alkaline hydrolysis.

Sedimentation and diffusion constants were determined for electrophoretically purified Vi antigen before and after mild alkaline hydrolysis. The molecular weight of the intact antigen was found to be 1.7 x 10(6).