COMPOSITION, DEGRADATION AND UTILIZATION OF ENDOSPERM DURING GERMINATION IN THE OIL PALM (ELAEIS-GUINEENSIS JACQ)
COMPOSITION, DEGRADATION AND UTILIZATION OF ENDOSPERM DURING GERMINATION IN THE OIL PALM (ELAEIS-GUINEENSIS JACQ)
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DOI：
10.1093/oxfordjournals.aob.a087553
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发表时间：
1988-02-01
期刊：
影响因子：
4.2
通讯作者：
JONES, LH
中科院分区：
文献类型：
--
作者：
ALANG, ZC;MOIR, GFJ;JONES, LH
不溶性碳水化合物和脂质部分，以及。-D-galactosidase度量。研究了油棕种子萌发前后不同组织中- d -甘露糖苷酶和异柠檬酸裂解酶的活性。在未发芽的籽粒中，不溶性碳水化合物和脂质分别占胚乳干重的36%和47%。在萌发过程中，厚的胚乳细胞壁明显变薄，同时不溶性碳水化合物的百分比显著降低，α含量显著增加。-半乳糖苷酶和。-甘露糖苷酶在降解和残留胚乳中的活性。降解胚乳中脂质比例也显著提高。不溶性碳水化合物似乎是位于胚乳次级壁的半乳甘露聚糖。在油棕胚和吸器中未检测到半乳甘露聚糖。异柠檬酸裂解酶存在于萌发籽粒的吸器组织中，并局限于其内部。该酶在胚乳萌发的任何阶段都不活跃，在抑制前和抑制结束时在胚胎中也不活跃。结果表明，半乳甘露聚糖是油棕胚乳的第二大成分，在萌发初期利用速度快于脂质。异柠檬酸裂解酶活性仅限于吸器的事实表明，甘油三酯转化为碳水化合物的糖异生过程完全发生在种子的子叶内。
The insoluble carbohydrate and lipid fractions, and .alpha.-D-galactosidase, .beta.-D-mannosidase and isocitrate lyase activities were studied in the various tissues of oil palm (Elaeis guineensis Jacq.) kernels prior to and during germination. In ungerminated kernels insoluble carbohydrate and lipid constituted 36 and 47% of endosperm dry weight respectively. During germination the thick endosperm cell wall became markedly thinner, concurrent with a significant decrease in the percentage of insoluble carbohydrate and an increase in .alpha.-galactosidase and .beta.-mannosidase activity in both degraded and residual endosperm. The proportion of lipid in degraded endosperm also increased significantly. The insoluble carbohydrate appears to be a galactomannan located in the secondary walls of the endosperm. No galactomannan was detected in oil palm embryos or haustoria. Isocitrate lyase was present in, and confined to, tissues of the haustorium of germinating kernels. The enzyme was not active in endosperm at any stage of germination, nor was it active in embryos before or at the end of inhibition. The results suggest that galactomannan is the second largest component of oil palm endosperm and that it is utilized more rapidly than lipid during the early stages of germination. The fact that isocitrate lyase activity is confined to the haustorium suggests that the Elaeis gluconeogenesis, the conversion of triglyceride to carbohydrate, takes place entirely within the cotyledon of the seed.