Figure 4.

Flavonoid compounds applied to cotyledons travel differentially to the root tip. The indicated compounds were applied to cotyledons and incubated overnight, and the resulting fluorescence was visualized following DPBA staining. The addition of N, DHK, and DHQ resulted in DPBA-flavonoid fluorescence in distal tissues, while K and Q did not result in fluorescence in any root tissue. The far right column shows a representative wild-type seedling for comparison. The red fluorescence in the tissues above the root/shoot junction is chlorophyll autofluorescence. Scale bar = 100 μm. Abbreviations: rsj, root/shoot junction; mr, midroot; rt, root tip.