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Regulation of thiophene biosynthesis by sulphate in roots of marigolds
Author(s) -
ARROO R. R. J.,
JACOBS J. J. M. R.,
GESTEL J. A. M.,
KENKEL H.,
JANNINK W.,
CROES A. F.,
WULLEMS G. J.
Publication year - 1997
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.1469-8137.1997.00637.x
Subject(s) - thiophene , cordycepin , chemistry , biosynthesis , elongation , metabolism , biochemistry , botany , biology , organic chemistry , enzyme , materials science , metallurgy , ultimate tensile strength
SUMMARY The incorporation of [ 35 S] sulphur in thiophenes by Tagetes patula roots was used as a model to study the regulation of secondary metabolism with a limited supply of substrate. Growth and thiophene accumulation were measured in root cultures incubated at various sulphate concentrations in the medium. A 20‐fold to 40‐fold reduction in the sulphate concentration did not affect elongation growth, branching and biomass production within 14 d but decreased the thiophene level to 25–50% of the control in the same period. The reduction in thiophene content was found to result from a decline in biosynthetic capacity of 80–95% after 8 d. This capacity was restored when roots were transferred to standard medium. The restoration took more than 24 h and was suppressed by cordycepin, an inhibitor of mRNA processing. It is concluded that the rate of thiophene synthesis is regulated by a control mechanism that reacts to the availability of sulphate to the roots.