Studies on the Interaction of Antiauxin and Native Auxin in Wheat Roots

An Active State of Auxin in Wheat Roots

“…It is the purpose of the present study to investigate the active state of IAA postulated from an earlier examination to exist in intact wheat roots (Fransson 1958). From that examination it was obvious that the active IAA form could not, with the technic used, be demonstrated to be present in the acidether fraction obtained from an ether extract of the roots.…”

“…The circumstance that the level of the free form of the native auxin increases in the presence of an antiauxin was advanced as a probable eonsequence of a competitive process assumed to take place between the two types of substances. Such an enhanced IAA level would at the same time also be an indication that a competition had really occurred, in which native IAA had been displaced from some of its natural sites (Fransson 1958). However, it should be pointed out here that the term competition is an incorrect designation for expressing what is really taking place between the antiauxin Physiol.…”

“…Tbe fact that tbe free IAA level increases in botb coleoptiles and roots, at tbe same time as tbe elongation intensity becomes lower in tbe coleoptiles but bigber in tbe roots, does not tally witb classic opinion of tbe effects of auxin on tbese two different types of tissues. Tberefore, from a purely experimental basis tbe conclusion was drawn that the free IAA form does not represent a state in wbich this auxin is active in the elongation (Fransson 1958). Nor can evidently any storage form of tbe protein or non-protein IAA types be considered to be an active state of tbe auxin (Fransson 1958).…”

“…Tberefore, from a purely experimental basis tbe conclusion was drawn that the free IAA form does not represent a state in wbich this auxin is active in the elongation (Fransson 1958). Nor can evidently any storage form of tbe protein or non-protein IAA types be considered to be an active state of tbe auxin (Fransson 1958).…”

“…It was concluded from earlier studies that the concentration of the native auxin indole-3-acetic acid (lAA) occurring in the free form in Avena coleoptiles and in wheat roots is not an expression of the magnitude of the growth activity of the tissue (Fransson andIngestad 1955, Fransson 1958).…”