Influence of IAA, NAA and 2,4-D on ethylene production by potato discs (Solanum tuberosum L. cv. Red Pontiac)

Various auxins induced an increase of ethylene production by potato discs (Solarium tuberosum L. cv. Red Pontiac). 2,4-Dichlorophenoxyacetic acid (2,4-D) at 10 μM was the most effective in stimulating ethylene (C₂H₄) production. Napthaleneacetic acid (NAA) and indole-3-acetic acid (IAA) also stimulated ethylene production with optimal concentrations of 50 μM and 100 μM, respectively. The periderm of the tuber was found to produce the highest levels of C₂H₄ with sections taken toward the center of the tuber producing much lower levels. In this system, it was shown that pH 4.0 was the optimum pH tested and methionine was required.