Figure 3.

Birefringence of cultured cotton fibers following either addition of exogenous H₂O₂ or inhibition of H₂O₂ generation by DPI. Cotton fibers were cultured with their associated fertilized ovules in 24-well plates at 30°C. a and b, Controls 15 DPA (a) or 16 DPA (b) to which only 0.1% DMSO was added 12 DPA. c and d, Fibers 15 DPA (c) or 16 DPA (d) to which 50 μm H₂O₂ was added once daily 13 and 14 DPA. e and f, Fibers 15 DPA (e) or 16 DPA (f) that had been cultured in 1 μm DPI/0.1% DMSO since 12 DPA. a, c, e, and f were viewed at ×250 magnification, whereas b and d were at ×100.