Figure 2.

Ethylene and H₂O₂ interact to regulated cotton fiber elongation. (A) Exogenous ethylene induced H₂O₂ production starting from an early stage. (B) Exogenous H₂O₂ slowly stimulated ethylene production. (C) A proposed model for a regulatory mechanism between H₂O₂ and ethylene signaling in controlling fiber elongation. Wide-type ovules were harvested at 1 dpa and in vitro cultured in the medium (CK), in presence of 50 µM H₂O₂ or 0.1 µM ethylene for the time (h or d) indicated. H₂O₂ content was measured using titanium oxidation method (23). gFW, gram fresh weight. Ethylene production from cultured wild-type ovules was determined according to the protocol described (ref. ¹⁷). Statistical significances were determined using one-way ANOVA software combined with Tukey's test. *p < 0.05; **p < 0.01; ***p < 0.001.