A negative image of the quiescent centre in regenerating root apices of Zea mays

Usually the presence of the quiescent centre in roots is demonstrated by the absence of labelled nuclei following treatment of the root with appropriate radioactive markers. By modification of the pulselabelling technique, a "negative" image of the quiescent center, showing more intense labelling from [(3)H]thymidine than the surrounding area, was obtained in regenerating root apices of Zea mays L.