Induced elongation plant hormones

The plasma membranes of growing plant cells select to incorporate sugars, amino adds, ions and other low molecular weight compounds from the apoplastic space, and then, the cells have a certain level of osmotic pressure. The difference between their osmotic pressure and their wall pressure (=turgor pressure) is due to motive power (suction force) to suck water from the apoplastic space (Figure 1). The plant hormone auxin, which decreases the wall pressure in a growing plant cell, therefore induces cell elongation or expansion. 

There is some evidence to suggest that / -glucanases may play a role in the expansion of yeast cells in the absence of cell duplication. Yanagishima (61) and Shimoda et al. (62) discovered that a plant hormone, auxin (indole-3-acetic acid), induced cell elongation in auxin-... 

Another compound with plant hormone-like activity is raphanusanin, a natural inhibitor of radish hypocotyl elongation which is believed to be instrumental in its phototropic response [179]. Raphanusanin has been reported to prevent auxin-induced MT reorientations [19]. However, there is no direct evidence that raphanusanin exerts an effect on MTs. 

Matthyssee and Phillips (20) isolated two nuclear proteins, from tobacco cells, that bound specifically to 2,4-D. Receptor proteins for auxins, kinetins, and GA have been found (21). Sub-cellular fractions from bean leaves were recently shown to bind abscisic acid (22). Preliminary experiments (22) indicated that maximum ABA binding activity coincides with the activities of membrane-bound Mg -dependent, K+-stimulated ATPase and glucan synthetase. Table I of Biswas and Roy (21) lists hormone receptor proteins reported in plant tissue. For a protein to qualify as a receptor molecule, it should have a high stereo-specific binding capacity (Kd 10 6 to 10 SM) for its particular hormone. In com coleoptiles, both IAA and NAA are equally effective in inducing cell elongations fractions of plasma membrane and endoplasmic reticular membrane contain receptor proteins with Kd values of 10 M to 10 M for auxins (5, 18). When one considers procedural... 

Identify compounds A and B, two synthetic intermediates in the 1979 synthesis of the plant growth hormone gibberellic acid by Corey and Smith. Gibberellic acid induces cell division and elongation, thus making plants tall and leaves large. 

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