Figure 1.

EPR spectra of TEMPONE in T. latifolia pollen. Pollen of approximately 0.37 g water g⁻¹ DW was incubated in a solution of 1 mm TEMPONE and 120 mm ferricyanide directly (a) and indirectly (b) after a previous 5 min of rehydration in germination medium. The TEMPONE at the outside of the pollen was fully broadened by ferricyanide. The permeability of the plasma membrane to ferricyanide can be calculated as the ratio between the line heights of the lipid fraction (left) and the aqueous cytoplasmic fraction (right) in the high-field region of the spectrum (L/W).