Open AccessA Role for Ethylene in the Metabolism of Cyanide by Higher Plants
Author(s) -
J. Stephen Goudey,
Forrest L. Tittle,
Margaret Beale Spencer
Publication year - 1989
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.89.4.1306
Subject(s) - ethylene , pisum , phaseolus , cyanide , biochemistry , seedling , sativum , chemistry , aminooxyacetic acid , atp synthase , biology , metabolism , ethephon , botany , enzyme , organic chemistry , catalysis
The action of ethylene on the capacity of plant tissues to metabolize cyanide to beta-cyanoalanine was examined. Beta-cyanoalanine synthase (EC 4.4.1.9) catalyzes the reaction between cyanide and cysteine to form beta-cyanoalanine and hydrogen sulfide. Levels of beta-cyanoalanine synthase activity in tissues of 6 day old etiolated pea (Pisum sativum) seedlings were enhanced severalfold by 1 microliter per liter ethylene. The promotive effect of ethylene increased with increasing ethylene concentrations from 0.01 to 100 microliters per liter and with the period of exposure from 3 to 24 hours. Ethylene enhanced beta-cyanoalanine synthase activity in all regions of the seedling (shoots and roots, internodal regions, cotyledons). The promotive effect was eliminated by norbornadiene, a competitive inhibitor of ethylene action. Levels of beta-cyanoalanine synthase in seedlings of four other dicots (Phaseolus aureas, Glycine max, Lactuca sativa, Sinapis arvensis) and two monocots (Hordeum vulgares, Triticum aestivum) were also increased in response to ethylene. Our results suggest an important regulatory role for ethylene in the metabolism of cyanide by higher plants.