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Acquisition of selenium tolerance by a selenium non‐accumulating Astragalus species via selection
Author(s) -
Wang Y.,
Böck A.,
Neuhierl B.
Publication year - 1999
Publication title -
biofactors
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.204
H-Index - 94
eISSN - 1872-8081
pISSN - 0951-6433
DOI - 10.1002/biof.5520090102
Subject(s) - selenium , selenocysteine , astragalus , biology , biochemistry , methyltransferase , in vivo , chemistry , botany , gene , genetics , enzyme , cysteine , medicine , alternative medicine , organic chemistry , traditional chinese medicine , pathology , methylation
Selection of cultured cells of the selenium sensitive and non‐accumulating Astragalus cicer for tolerance to stepwise increasing concentrations of selenite in the medium lead to a variant able to grow at 75 μM selenite. The Se‐tolerant culture synthesized a selenocysteine methyltransferase immunologically related but not identical to that of the accumulating A. bisulcatus species and produced Se‐methyl‐selenocysteine in vivo . Re‐cultivation in selenium‐free medium lead to breakdown of tolerance and the disappearance of the methyltransferase from cellular proteins. The results prove that the non‐accumulating species A. cicer has the cryptic capacity for synthesis of a selenocysteine methyltransferase and also demonstrate that synthesis of the organoselenium compounds in Se‐accumulating plants are contributing to selenium tolerance.