Occurrence of potential brassinosteroid precursor steroids in seeds of wheat [Triticum aestivum] and foxtail millet [Setaria italica]
1999
Takatsuto, S. (Joetsu Univ. of Education, Niigata (Japan)) | Kosuga, N. | Abe, B. | Noguchi, T. | Fujioka, S. | Yokota, T.
The seeds of wheat (Triticum aestivum L.) and foxtail millet (Setaria italica Beauv.) were found by GC-MS to contain, in addition to bulk sterols, 4-en-3-one steroids including 24-ethylcholesta-4,24(28)Z-dien-3-one (a new steroid), 24-methylcholest-4-en-3-one, 24-ethylcholesta-4,22E-dien-3-one and 24-ethylcholest-4-en-3-one, as well as 5alpha-steroidal 3-one compounds including 24-methyl-5alpha-cholestan-3-one, 24-ethyl-5alpha-cholestan-3-one and 24-ethyl-5alpha-cholest-22E-en-3-one (in S. italica only). Analysis of free sterol and steryl ester fractions indicated that campestanol and sitostanol were present at high levels in both seeds. These results suggest that the seeds of T. aestivum and S. italica synthesize campestanol from campesterol via 24-methylcholest-4-en-3-one and 24-methyl-5alpha-cholestan-3-one as has already been demonstrated in Arabidopsis thaliana L. and also produce sitostanol from sitostanol via 24-ethylcholest-4-en-3-one and 24-ethyl-5alpha-cholestan-3-one. Biosynthetic relationships of campestanol and sitostanol C28 and C29 brassinosteroids are discussed
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