Separation and characterization of A- and B-type starch granules in wheat endosperm
Separation and characterization of A- and B-type starch granules in wheat endosperm
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DOI：
10.1094/cchem.1999.76.3.375
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发表时间：
1999-05-01
期刊：
影响因子：
2.4
通讯作者：
Chibbar, RN
中科院分区：
文献类型：
--
作者：
Peng, M;Gao, M;Chibbar, RN
成熟小麦（Triticum aestivum L.）胚乳含有两种类型的淀粉粒：大A型和小B型。本文用蔗糖、麦芽糖或Percoll水溶液离心沉淀法和微筛法分离了A型和B型淀粉颗粒。微筛不能完全分离这两种类型的淀粉颗粒，而麦芽糖和蔗糖溶液中的溶解仅得到了B型淀粉颗粒的均一群体。通过两个Percoll溶液（70和100%，v/v）的浸渍产生纯化的人口的A-和B-型淀粉颗粒。对纯化的A型和B型淀粉粒群体以及直接从小麦胚乳中获得的全淀粉粒群体中的淀粉粒粒度分布进行了分析，证实纯化的A型和B型淀粉粒群体代表了成熟小麦胚乳中的对应物。用两种Percoll溶液对6个小麦品种的A型和B型淀粉粒群体进行了纯化。分析了这些群体的直链淀粉含量和糊化特性。所有A型淀粉颗粒含有较高的直链淀粉浓度，并有较高的糊化淀粉比B型淀粉颗粒。虽然A型和B型淀粉颗粒在相似的温度下开始糊化，但B型淀粉颗粒具有比A型淀粉颗粒更高的糊化峰值和完成温度。
Mature wheat (Triticum aestivum L.) endosperm contains two types of starch granules: large A-type and small B-type. Two methods, microsieving or centrifugal sedimentation through aqueous solutions of sucrose, maltose, or Percoll were used to separate A- and B-type starch granules. Microsieving could not completely separate the two types of starch granules, while centrifuging through maltose and sucrose solutions gave a homogenous population for B-type starch granules only. Centrifuging through two Percoll solutions (70 and 100%, v/v) produced purified populations of both the A- and B-type starch granules. Analysis of starch granule size distribution in the purified A- and B-type granule populations and in the whole-starch granule population obtained directly from wheat endosperm confirmed that the purified A- and B-type starch granule populations represented their counterparts in mature wheat endosperm. Centrifugations through two Percoll solutions were used to purify A- and B-type starch granule populations from six wheat cultivars. The amylose concentrations and gelatinization properties of these populations were analyzed. All of the A-type starch granules contained higher amylose concentrations and had higher gelatinization enthalpies than did B-type starch granules. Although A- and B-type starch granules started to gelatinize at a similar temperature, B-type starch granules had higher gelatinization peak and completion temperatures than did A-type starch granules.