Reserve carbohydrate metabolism in germinating seeds of trigonella foenum-graecum L. (Leguminosae).
Seeds of Trigonella foenum-graecum are examined light microscopically and by chemical analysis at different stages of germination.In the earliest stages of germination the raffinose family oligosaccharides are metabolised both in the endosperm and in the cotyledons of the seed but there is no change in the appearance, amount or composition of the main carbohydrate reserve, a galactomannan localised in the endosperm. About 18 hours after the emergence of the radicle the endosperm galactomannan begins to be mobilised. In a period of 24 hours the polysaccharide is completely degraded and the breakdown products, mainly galactose and mannose, are absorbed by the cotyledons in which sucrose increases and starch is formed.Mobilisation of the galactomannan is accompanied by the formation in the endosperm of a dissolution zone the form of which implies that the aleurone layer is involved in the degradation process.
Institut für botanische Biologie und Phytochemie, Universität Freiburg, Schweiz.
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JS
Reid