Metabolism auxin activity

Thus, anthraquinone synthesis in cell suspension cultures of Morinda oitrifolia depends strictly on auxins. However, among 14-6 substances showing auxin activity tested by Zenk et al. (37), only a few were able to trigger anthraquinone metabolism. Naphthalene-1-acetic acid was the most effective one. In contrast, the same cells cultivated in a medium containing 2,4-i) as the only auxin did not produce anthraquinone. 

The pathway of ethylene biosynthesis in higher plants is from l-methionine4 (Figure 5.9). Methionine is an intermediate in other metabolic processes and the control of ethylene biosynthesis via the interference of methionine production is not realistic. The ACC synthase step from S-adenosyl methionine to ACC appears more susceptible to chemical modification auxin promotes ethylene production by increasing the activity of ACC synthase. Subsequent steps from ACC are less controlled and ethylene is readily produced from the conversion of ACC in most tissues. 

Efforts are being made to clarify the relationships of auxins with metal ions present in plant systems.42- 1 This topic is irrelevant here, except for noting that it is considered that the auxins are transported to centers of high metabolic activity where they may act as mobilization centers for the metallic ions. Whether or not this view will hold is still not clear however, it has been found that carbohydrates and nitrogeneous substances are strongly attracted to these centers of induced metabolism. 

Many of the same conclusions may be drawn from results with synthetic auxins as from indole-3-acetic acid water intake increased, there was a lessening of the downward translocation of photosynthate with temporary increases of soluble carbohydrates in the leaves, and alterations appeared in the metabolic ratq and direction and in enzyme activity. However, the direct site of action is not known, and many of the effects are puzzling. n-Fructose oligosaccharides in artichoke and chicory storage-tissue were diminished by 70% (calculated on the content of dry matter) in 6 days... 

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