TITLE	In vitro binding of gibberellin A4 in epicotyls of dwarf pea
AUTHOR	Zin-Huang Liu Department of Biology, Institute of Life Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan, ROC Bor-Heng Lee Department of Biology, Institute of Life Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan, ROC
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ABSTRACT	In vitro gibberellin (GA) binding properties of a cytosol fraction from epicotyls of dwarf pea (Pisum sativum L. cv. Progress No. 9) were investigated using [3H]GA4 in a DEAE filter paper assay at 4°C. The binding obtained is saturable, reversible, and temperature labile in dwarf pea, and has a half-life of dissociation of 5-6 min. By varying the concentration of [3H]GA4 in the incubation medium, the Kd was estimated to be 130 nM. The number of binding sites (n) was estimated to be 0.66 pmole mg-1 soluble protein. In competition binding assays, biologically active GAs, such as GA3 and GA4, could compete with [3H]GA4 for binding sites more successfully than could the biologically inactive GA4 methyl ester or epi-GA4. The influence of light on gibberellin-binding proteins in dwarf pea was also studied. The Kd and n of the GA-binding proteins for [3H]GA4 in light-treated tissues were close to the values for Kd and n in the dark grown tissues¡Xlight has little influence on gibberellin A4-binding proteins.
KEYWORD	GA-binding proteins; Gibberellin; Pisum sativum;
ARTICLE INFO	Botanical Bulletin of Academia Sinica, Volume 36 Number 2 April 1995, page 73-79, 7 pages
PUBLISHER	Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, Republic of China