Heteroauxin

heteroauxin [¦hed·ə·rō′ȯk·sən]

(biochemistry)

C₁₀H₉O₂N A plant growth hormone with an indole skeleton.

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Heteroauxin 

also β-indolylacetic acid, C₁₀H₉NO₂, a highly physiologically active chemical compound, formed in plants and affecting growth processes (the so-called growth hormone); one of the most widely distributed auxins.

The Dutch chemist F. Kögl and his co-workers first isolated heteroauxin in 1934 from cultures of molds and other microorganisms; later it was also discovered in higher plants. It is formed in leaves from the amino acid tryptophan and then migrates to the growing stems and roots of plants, where it is oxidized to an active state. Heteroauxin is the only auxin prepared synthetically. The comparative simplicity of synthesizing it facilitated study of the action of heteroauxin on the plant organism, as well as its use in horticulture, for example, for accelerating the formation of roots when propagating plants by cuttings. (It is often used along with vitamin C and the B vitamins.) The heteroauxin doses vary from 50 to 200 mg per liter depending on the degree of lignification of the plant propagated by cuttings.

R. KH. TURETSKAIA and V. I. KEFELI