Britz Steven J, Kremer Diane F
USDA ARS, Phytonutrients Laboratory, Beltsville Agricultural Research Center, Beltsville Human Nutrition Research Center, Beltsville, Maryland, USA.
J Agric Food Chem. 2002 Oct 9;50(21):6058-63. doi: 10.1021/jf0200016.
Soybean seeds are an important source of dietary tocopherols, but like seeds of other dicotyledonous plants, they contain relatively little alpha-tocopherol, the form with the greatest vitamin E activity. To evaluate potential effects of environmental stress during seed maturation on tocopherols, soybeans were raised in greenhouses at nominal average temperatures of 23 degrees C or 28 degrees C during seed fill, with or without simultaneous drought (soil moisture at 10-25% of capacity), during normal growing seasons in 1999 (cvs. Essex and Forrest) and 2000 (cvs. Essex, Forrest, and Williams). Total free (nonesterified) tocopherols increased slightly in response to drought in Essex and Forrest. All three lines responded to elevated temperature and, to a lesser extent, drought with large (2-3-fold) increases in alpha-tocopherol and corresponding decreases in delta-tocopherol and gamma-tocopherol. The results suggest that weather or climate can significantly affect seed tocopherols. It may be possible to breed for elevated alpha-tocopherols by selecting for altered plant response to temperature.
大豆种子是膳食生育酚的重要来源，但与其他双子叶植物的种子一样，它们含有的α-生育酚相对较少，而α-生育酚是维生素E活性最强的形式。为了评估种子成熟期间环境胁迫对生育酚的潜在影响，于1999年（品种为埃塞克斯和福里斯特）和2000年（品种为埃塞克斯、福里斯特和威廉姆斯）的正常生长季节，在种子灌浆期将大豆种植在温室中，名义平均温度为23摄氏度或28摄氏度，同时设置有或没有干旱胁迫（土壤湿度为田间持水量的10%-25%）的处理。埃塞克斯和福里斯特品种中，总游离（非酯化）生育酚因干旱胁迫略有增加。所有三个品种都对温度升高有响应，并且在较小程度上对干旱有响应，α-生育酚大幅增加（2-3倍），同时δ-生育酚和γ-生育酚相应减少。结果表明，天气或气候会显著影响种子生育酚含量。通过选择改变植物对温度的响应，有可能培育出α-生育酚含量更高的品种。
