Translocation gibberellin

Similar experiments were performed on older shoots 5 or 6 feet long. There was little or no translocation of gibberellin from one shoot to another (43). 

Gibberellin readily translocates within a shoot. If one leaf is treated, the compound moves to the apical growing region and there stimulates growth. This fact has been used in studies of absorption and/or translocatability of different gibberellins in the grape (39). 

Results. The analytical results summarized in Table I show that during the early growth period gibberellin was translocated into the leaves and rhizomes. However, largely because of the mass increase, the residual amounts found in the new potatoes were very small. 

Results. The analytical data are summarized in Table II. Absorption of the gibberellin from its solution is more nearly complete at the lower concentration range, and the applied material is relatively little degraded during germination and drying. The data clearly indicate translocation of gibberellin into the sprouts. 

Translocation of C14-Gibberellin in Red Kidney Bean, Normal Cora, and Dwarf Corn... 

Treatment of Com. Ten microliters of an 80% acetone solution, containing 100 fig. of C14-gibberellin, was applied with a micropipet near the middle of the upper surface of the first leaf, followed by 10 fjl. of 0.1% Tween 20 and 50% ethyl alcohol in order to increase absorption of the radioactive material. The drop of solution was kept from running down by means of lanolin paste. Four normal and four dwarf com plants were thus treated, while untreated plants were kept as controls. The same number of dwarf plants was treated with 0.05 fic. of C14-5-aminotriazole in order to compare the pattern of translocation of gibberellin with that of a compound whose movement has been studied previously (4). The treated plants and controls were then placed in the growth chamber, and one or two specimens were harvested at the end of 1, 2, and 7 days, freeze-dried, and autoradiographed. 

The movements of C14-gibberellin was compared with that of C14-5-amino-triazole in com plants. The translocation of aminotriazole has been studied (4) and shown to occur readily from mature green leaves to the growing regions, in-... 

Diterpenes (C20) can be linear as in the phytol part of chlorophyll or mono- to tetracyclic.87 Very well researched are the tricyclic taxanes of which taxol A from the Taxus baccata tree inhibits cell division and has found use in anticancer treatment. Certain labdanes inhibit blood platelet aggregation and kaurane norditer-pene glycosyl ester atractylosides from the Mediterranean thistle block the ATP/ADP translocation - such diterpenes are very toxic when ingested. Ubiquitous plant-derived kaurane-type diterpenes are the plant hormones (gibberellins) or defense substances (phytoalexins). 

Ancymidol is classified as a plant growth regulator and has a wide application. It is taken up and translocated in the phloem and inhibits internode elongation by inhibiting the CYP enzyme in the biosynthetic pathway of gibberellins. The structures of the three above-mentioned compounds are reasonably similar ... 

Endogenous growth regulators may be translocated in the plant s vascular systems. This would seem to hold especially true for gibberellins and cytokinins, since activity has been detected in the xylem sap of many different herbaceous as well as woody species. Obviously these hormones are also exported from photosynthesizing leaves, as indicated by their presence in sieve tube sap. Although with less frequency, also auxin and ABA-like activity have been detected in both xylem and phloem sap (Table 3.1). 

Asakawa Y, Tamari K, Inoue K, Kaji J (1974) Studies on metabolism of gibberellin A3 in plant. 1. Translocation and intracellular distribution of tritiated gibberellin A3. Agric Biol Chem 38 713-717... 

Chin TY, Lockhart JA (1965) Translocation of applied gibberellin in bean seedlings. Am J Bot 52 828-833... 

Cleland RE (1975) Auxin-induced hydrogen ion excretion correlation with growth, and control by external pH and water stress. Planta 127 233-242 Cleland RE (1976) Kinetics of hormone-induced H excretion. Plant Physiol 58 210-213 Cleland RE, Prins H, Harper R, Higinbotham N (1977) Rapid hormone-induced hyperpolarization of the oat coleoptile transmembrane potential. Plant Physiol 59 395-397 Clor MA (1967) Translocation of tritium-labelled gibberellic acid in pea stem segments and potato tuber cylinders. Nature 214 1263-1264 Cohen D, Robinson JB, Paleg LG (1966) Decapitated peas and diffusible gibberellins. Aust J Biol Sci 19 535-543... 

Zweig G, Yamaguchi S, Mason GM (1961) Translocation of C -gibberellin in red kidney bean, normal corn and dwarf corn. Adv Chem Ser 28 122-134... 

Translocation of synthesized gibberellin to aleurone layer (although see text). Coleorhiza ruptures coat... 

SO the completed vascular system is ready at an early stage for translocation of metabolites from the scutellum to the embryo, and/or (if it occurs) for the transport of gibberellins synthesized at the node to the scutellum, whence they can be released. There is evidence, coming from the use of radioactive gibberellic acid, that this hormone can indeed be transported through the vascular strand of the scutellum [112]. 

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