标题：COMPARATIVE SUSCEPTIBILITY TO AMYLASES OF STARCH GRANULES OF SEVERAL SINGLE ENDOSPERM MUTANTS REPRESENTATIVE OF FLOURY-OPAQUE, STARCH-DEFICIENT, AND MODIFIED STARCH TYPES AND THEIR DOUBLE-MUTANT COMBINATIONS WITH OPAQUE-2 IN FOUR INBRED LINES OF MAIZE
期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1978
卷号：24
期号：4
页码：437-448
DOI：10.3177/jnsv.24.437
出版社：Center for Academic Publications Japan
摘要：Starch granules were prepared from kernels of eight single endosperm mutants, brittle -1 ( bt 1), brittle-2 ( bt 2), floury -1, floury -2, soft starch, opaque -1 ( o 1), shrunken -2 ( sh 2), and sugary -2 ( su 2), and their double-mutant combinations with opaque -2 ( O 2) of four inbred lines of maize ( Zea mays L.), B37, C103, Oh43 and W64A. We compared the susceptibility of various starch granules to Rhizopus glucoamylase and pancreatin. Starch granules of the su 2 and su 2 o 2 mutants were digested by amylases much faster than those of the normal counterparts. Starch granules of the bt 1, bt 2, o 1 and sh 2 mutants tended to be digested by amylases faster than those of normal maize. Starch granules of doublemutant combinations with the o 2 gene were, in general, digested to an extent very comparable to their respective non-opaque single mutant counterparts in each of their four inbred backgrounds. We followed the relative digestion of starch granules by using scanning electron microscopy. Starch granules of endosperm mutants susceptible to amylases showed numerous pin holes on the surface layer and the pores penetrated into the inner layers of the granules during the attack by amylases. In some of the granules the inner portion, which appeared terraced or step-shaped, could be seen. This may be indicative of layered internal structures of the granules.
