Effect of Endosperm Removal on 7 Normal NaOH-Labile Indole-3-acetic Acid Conjugates in Shoots and Roots of Zea mays Seedlings.

The pool of amide-linked indole-3-acetic acid (amide IAA) in the shoot of growing etiolated seedlings of Zea mays increases between the 3rd and 5th day of germination to equal the amount of free IAA and two-thirds the amount of ester IAA. Deseeding the germinant changes the pool size of free and amide IAA in a manner suggestive of conversion of endogenous free IAA to amide IAA. Deseeding also caused an almost total disappearance of amide IAA from the root, demonstrating that the pool of amide IAA is not inert and can be actively metabolized in young Z. mays seedlings.