%0 Journal Article
%T Genetic variation of ¦Ã-tocopherol methyltransferase gene contributes to elevated ¦Á-tocopherol content in soybean seeds
%A Maria S Dwiyanti
%A Tetsuya Yamada
%A Masako Sato
%A Jun Abe
%A Keisuke Kitamura
%J BMC Plant Biology
%D 2011
%I BioMed Central
%R 10.1186/1471-2229-11-152
%X Through QTL analysis and fine mapping in populations from a cross between KAS and a Japanese variety Ichihime, we identified ¦Ã-TMT3, which encodes ¦Ã-tocopherol methyltransferase, as a candidate gene responsible for high ¦Á-tocopherol concentration in KAS. Several nucleotide polymorphisms including two nonsynonymous mutations were found in the coding region of ¦Ã-TMT3 between Ichihime and KAS, but none of which was responsible for the difference in ¦Á-tocopherol concentration. Therefore, we focused on transcriptional regulation of ¦Ã-TMT3 in developing seeds and leaves. An F5 line that was heterozygous for the region containing ¦Ã-TMT3 was self-pollinated. From among the progeny, plants that were homozygous at the ¦Ã-TMT3 locus were chosen for further evaluation. The expression level of ¦Ã-TMT3 was higher both in developing seeds and leaves of plants homozygous for the ¦Ã-TMT3 allele from KAS. The higher expression level was closely correlated with high ¦Á-tocopherol content in developing seeds. We generated transgenic Arabidopsis plants harboring GUS gene under the control of ¦Ã-TMT3 promoter from KAS or Ichihime. The GUS activity assay showed that the activity of ¦Ã-TMT3 promoter from KAS was higher than that of Ichihime.The genetic variation in ¦Ã-TMT3, which plays a major role in determining ¦Á-tocopherol concentration, provides significant information about the regulation of tocopherol biosynthesis in soybean seeds. This knowledge will help breeding programs to develop new soybean varieties with high ¦Á-tocopherol content.The vitamin E family comprises tocopherols (¦Á, ¦Â, ¦Ã, and ¦Ä forms) and tocotrienols (¦Á, ¦Â, ¦Ã, and ¦Ä forms). All isoforms possess lipid antioxidant activity, and ¦Á-tocopherol possesses the highest vitamin E activity in mammals [1,2]. Vitamin E is widely used as an antioxidant in foods and oils, as a nutrient additive in poultry and cattle feeds to improve meat quality, and as a supplement in the human diet to help prevent diseases such as cancer and cardiovasc
%U http://www.biomedcentral.com/1471-2229/11/152