Auxin enhancement

With respect to the first of these hypotheses, auxin enhances the rate of wall synthesis in virtually every tissue in which growth is also promoted.482,483 It seems certain that this stimulation extends to all components of the wall polysaccharide6,484 and to wall glycoprotein.485,486 Auxin has been shown to stimulate / -D-glucan synthetase activity in several plant-tissues.7,487... 

Treatment of the seedlings with auxins enhanced the TDC activity the light-induction of DAT (see earlier discussion) was delayed 24 h through such a treatment (301). The finding that heterotrophic cell cultures of C. roseus contain vindoline 235) is in accordance with vindoline biosynthesis being found in the green tissues of the plant. 

The most common effects of cytokinin, ethylene, and abscisic acid on stem and coleoptile cell elongation are inhibitory. They inhibit both auxin-enhanced... 

Auxin enhances ethylene production in roots (Chadwick and Burg 1967,... 

Cell-wall loosening and a concomitant increase of growth rate can be elicited by acidification. It is assumed that auxin stimulates a plasma membrane H+-ATPase that causes the acidification. A lateral translocation of auxin during unilateral irradiation would thus lead to differential acidification and thus differential growth. In Zea coleoptiles, auxin enhances the exocytosis and the synthesis of H+-ATPase of the plasma membrane, and also the activation of existing H+-ATPase was demonstrated. The strong and critical points of this so-called acid-growth theory were discussed. ... 

Orlova I, Marshall-Colon A, Schnepp J, Wood B, Varbanova M, Fridman E, Blakeslee JJ, Peer WA, Murphy AS, Rhodes D, Pichersky E, Dudareva N (2006) Reduction of benzoid synthesis in petunia flowers reveals multiple pathways to benzoic acid and enhancement in auxin transport. Plant Cell 18 3458-3475... 

In the presence of adenine and kinetin, orotic acid or thymine can enhance the production of flower buds in vitro in stem segments of Plumbago indica [ 187]. The production of buds is often inhibited by auxins and gibbereUns [ 188]. 

Auxins produce many changes in cells, including increased wall plasticity, enhanced respiratory rate and alterations in nucleic acid metabolism. Although the primary mode of action of auxins is not fully understood the development of the chemistry has progressed rapidly. Early discoveries identified and exploited the herbicide potential of super-optimal concentrations of auxin (Chapter 2, Herbicides) but their... 

Enhancement of Gibberellin and Auxin Action by Alkyl Lipides... 

Ethylene as a stimulator of growth and development. The most observed actions of ethylene on growing plants involves growth inhibition, or acceleration of senescence. These actions are especially evident in the antagonism or opposition of ethylene to auxins, gibberellins and cytokinins (27), as already outlined above. Actually ethylene stimulates growth in many types of cells, especially in water plants (Table II). When ethylene acts to stimulate cell elongation, as in water plants, auxins and CC>2 enhance the ethylene effect (38,39). This interaction is the reverse of that observed on land plants wherein ethylene opposes the effects of auxin, GA3 and cytokinins. 

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