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Metabolism of reduced and inorganic sulphur in pea cotyledons and distribution into developing seedlings
Author(s) -
Herschbach Cornelia,
Pilch Birgit,
Tausz Michael,
Rennenberg Heinz,
Grill Dieter
Publication year - 2002
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.0028-646x.2001.00295.x
Subject(s) - cotyledon , pisum , shoot , sativum , sulfur , cysteine , botany , chemistry , biology , aminooxyacetic acid , biochemistry , enzyme , organic chemistry
Summary• Sulphur export and redistribution from the cotyledons of pea ( Pisum sativum ) seedlings was investigated to determine the role of cotyledons as a sulphur source during root–shoot axis development. • Thiols and sulphate were analysed using standard biochemical techniques, and 35 S fed to cotyledons by injection. • After 35 S‐cysteine injection, c . 50% of the labelled S in the cotyledon was metabolized to 35 S‐sulphate. This reaction was partly inhibited by aminooxyacetic acid, an inhibitor of cysteine‐desulfhydrase. After 35 S‐sulphate application, c . 1% of the radiolabel was found in cysteine and glutathione in the cotyledon. After 2 h, c . 20% of the 35 S was transported into the root–shoot axis independently of whether 35 S‐sulphate or 35 S‐cysteine was injected into the cotyledon. After 4 h, 40% of 35 S was found outside the cotyledon. • Cotyledons of pea seedlings are capable of sulphate assimilation and cysteine degradation. Both sulphate and reduced sulphur were allocated from the cotyledons to the developing tissues of the pea seedlings.