Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164.
Plant Physiol. 1982 Jan;69(1):220-5. doi: 10.1104/pp.69.1.220.
Wheat kernels from myo-[2-(3)H]inositol- or scyllo-[R-(3)H]inositol-labeled plants (Sasaki and Loewus 1980 Plant Physiol 66: 740-745) were used to study redistribution of (3)H into growing regions during germination. Most of the labeled 1-alpha-galactinol (or the analogous scyllo-inositol galactoside) was hydrolyzed within 1 day. Water-soluble phytate was dephosphorylated within 3 days. A large reserve of bound phytate continued to release myo-inositol over several days. Translocation of free myo-inositol to growing regions provided substrate for the myo-inositol oxidation pathway and incorporation of (3)H into new cell wall polysaccharides.Cell wall polysaccharides in the kernel were degraded during germination. The labeled residues were translocated to growing regions and reutilized for new cell wall formation. Pentosyl residues accounted for most of this label.Free scyllo-inositol followed a path of translocation from kernel to seedling similar to that of myo-inositol. Unlike myo-inositol, it did not furnish substrate for the myo-inositol oxidation pathway but accumulated as free scyllo-inositol in the seedling.The fate of phytate-derived myo-inositol during germination of wheat is discussed in relation to a recent scheme of phytate metabolism proposed by De and Biswas (1979 J Biol Chem 254: 8717-8719) for germinating mung bean seedlings.
来自 myo-[2-(3)H]肌醇或 scyllo-[R-(3)H]肌醇标记植物的小麦籽粒（Sasaki 和 Loewus，1980 年《植物生理学》66：740-745）被用于研究萌发过程中（3）H 在生长区域中的再分配。大部分标记的 1-α-半乳糖肌醇（或类似的 scyllo-肌醇半乳糖苷）在 1 天内被水解。水溶性植酸盐在 3 天内去磷酸化。大量结合的植酸盐继续在数天内释放肌醇。游离肌醇向生长区域的转运为肌醇氧化途径提供了底物，并将（3）H 掺入新的细胞壁多糖中。在萌发过程中，籽粒中的细胞壁多糖被降解。标记的残留物被转运到生长区域，并重新用于新的细胞壁形成。戊糖残基占了大部分的标记物。游离的 scyllo-肌醇的转运途径与肌醇相似，从籽粒到幼苗。与肌醇不同，它不为肌醇氧化途径提供底物，而是作为游离的 scyllo-肌醇在幼苗中积累。本文讨论了在小麦萌发过程中植酸盐衍生的肌醇的命运，这与 De 和 Biswas（1979 年《生物化学杂志》254：8717-8719）最近提出的植酸盐代谢方案有关，该方案适用于萌发的绿豆幼苗。
