Abscisic receptors

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... 

Among the most noticeable findings from the research on plant hormones, the identification of receptors and receptor genes must be emphasized. In the last decade, since the publication of the previous edition of the book Comprehensive Natural Products Chemistry,5 the receptors and the receptor genes for ethylene, BRs, cytokinins, auxins, GAs, and abscisic acid have been identified, as described in the section for each plant hormone. 

Structure-activity correlations for abscisic acid are thus far from settled. There is evidence that there may be multiple receptors. Synthesis, assessment, and determination of the metabolic fate of chiral analogues is needed, together with analysis at the molecular level. Some progress is now being made in this direction [24,27,32]. 

I 18 The Identification of the Molecular Receptor of the Plant Hormone Abscisic Acid Dormancy Germination... 

Santiago, ]., Dupeux, F., Round, A., Antoni, R., Park, S.Y, jamin, M., Cutler, S.R., Rodriguez, P.L., and Marquez, J.A. (2009) The abscisic acid receptor PYRl in complex with abscisic acid. Nature, 462, 665-668. 

After CTS signals enter the cytoplasm via receptors, the CTS signals are transmitted quickly and build up a complicated network. Much work has been done to elucidate this signal netwoik, but it is still unclear. According to previously published papers, Ca , ROS, nitric oxide (NO), abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA) all take part in CTS signal pathway. 

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