Hormone-induced repression of a peroxidase isozyme in plant tissue

Young stem sections of dwarf peas (Progress No. 9) grown in light contain at least seven peroxidase isozymes separable by electrophoresis on starch gel. An eighth isozyme appears as the tissue elongates and ages, on or off the plant. The appearance of this isozyme in excised sections is repressed by application of the plant growth hormone, indole-3-acetic acid.