Translocation kinetin

It is possible that, over these longer periods, protein synthesis is affected. Itai Vaadia (1965, 1971) showed that during water stress cytokinin activity in the root exduate and translocation of cytokinin were reduced. Ben-Zioni, Itai Vaadia (1967) showed that the lower rate of protein synthesis of stressed leaf tissue could be raised by treatment of leaf material with kinetin. We need more information on levels of various proteins after naturally occurring stress. 

C. are synthesized mainly in the roots of higher plants and they are not subject to much translocation. It is interesting that they occur in certain transfer RNA molecules 0.05 to 0.1 % of the purine bases in tRNA have cytokinin activity. In E. coli, the tRNA species for phenylalanine, leucine, serine, tyrosine and tryptophan contain C. N -(y,y -dimethylallyl)-Adenosine (see) also occurs in the free form. The most important C. are Kinetin (see), Zeatin (see) and Dihydrozeatin (see). The synthetic C, A-benzyl-adenine (see 6-Benzylaminopurine) and SD 8339 (Fig. 2) also have high cytokinin activity. 

In summary, purines, kinetin and its artificial analogues, benzimidazole, indoleacetic acid, triiodobenzoic acid, 2,4-dichlorophenoxyacetic acid and a hypothetical root substance show ceitain common effects. However, they do not manifest themselves in all the investigated materials in the same way, possibly because some are quickly decomposed or translocated. One of the most general effects is the retardation of yellowing of excised leaves or leaf parts. For some of these substances, especially kinetin, other effects have been observed, but it is not known whether they are characteristic for the other substances. Among these effects are active transport, accumulation... 

After feeding the tips of intact primary roots of Phaseolus seedlings with aqueous solutions of labeled hormones by means of 1 jil-droplets (which were quickly absorbed), percentages of 30, 10, 4, and 1 of the label from kinetin, ABA, GAi, and lAA, respectively, were translocated into the shoot system during the subsequent 24 h. Most of the shoot s kinetin label was detected in the apical bud and primary leaves, although in all cases radioactivity was found in lateral and adventitious roots, about 10% for the ABA and 3% for the other hormones (Hartung 1977). 

Lagerstedt HB, Langston RG (1967) Translocation of radioactive kinetin. Plant Physiol 42 611-622... 

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