Premium
Cysteine‐induced H 2 S emission, ATP depletion, and membrane electrical responses in oat coleoptiles
Author(s) -
Kinraide Thomas B.,
Staley Thomas E.
Publication year - 1985
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1985.tb02339.x
Subject(s) - coleoptile , avena , cysteine , chemistry , biochemistry , incubation , intracellular , biophysics , biology , enzyme , botany
Incubation of oat ( Avena sativa L. cv. Victory) coleoptile segments in 4 m M L‐cysteine reduced the tissue ATP level to 42 nmol ( g fresh weight) −1 (35% of normal) over a 2 h period. Emissions of H 2 S accompanied this depletion in ATP suggesting an H 2 S production by desulfhydration of cysteine similar to that reported in other plants. Additions of exogenous H 2 S to the sections also caused ATP depletion. Aminooxyacetate, an inhibitor of cysteine desulfhydrase (EC 4.4.1.1), eliminated the cysteine‐induced H 2 S emission and the ATP depletion. Prolonged exposure to cysteine depressed the electrical polarity of the cell membrane from – 116 mV to –85 mV. That and other electrical responses appear to reflect a reduced capacity for ATP‐dependent H + extrusion. These effects should be taken into account whenever cysteine is used in physiological experiments.