Gene expression auxins

Guilfoyle, T. 1986. Auxin-regulated gene expression in higher plants. Crit. Rev. Plant Sci. 4 247-276. 

Hagen, G. 1987. The control of gene expression by auxin. In, Plant Hormones and Their Role in Plant Growth and Development, ed. P. J. Davies, pp. 149-163. Boston Martinus Nijhoff. 

Hagen, G., Kleinschmidt, A., Guilfoyle, T. 1984. Auxin-regulated gene expression in intact soybean hypocotyl and excised hypocotyl sections. Planta 762 147-153. 

Kulaeva et al. (29) have demonstrated modified gene expression in leaf tissue after administration of BR, with several new proteins being induced, and evidence for concentration effects. Also, Clouse et al (30) have reported new polypeptides, and up and down regulation in auxin-sensitive soybean stem segments treated with BR. 

There are three major classes of synthetic auxins the aryl acetic acids, which include indoleacetic acid (lAA) itself (Fig. 1 structure 2-1) and 1-naphthyl acetic acid (2-4), phenoxy acetic acids, represented by 2,4-dichlorophenoxy acetic acid (2,4-D) (2-7) and the benzoic acids, e.g. 2,3,6-trichloro benzoic acid (2-9). It remains the case however, that there is no stmcture-activity proposal which satisfactorily covers all molecules which are known to have auxin activity. As is well known, auxins have multiple effects, including promotion of cell elongation, cell division and gene expression. There may well be different receptors for each effect, and differences between receptors. An auxin binding protein (ABP), has now been characterised, and is possibly a receptor controlling cell elongation [3]. 

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