Biochemical analysis of new type mutants of japonica rice that accumulate water-soluble α-glucans in the endosperm but retain full starch debranching enzyme activities
In: Starch - Stärke, Jg. 69 (2016-08-12), S. 1600159-1600159
Online
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Zugriff:
Amylopectin has a highly regulated branched structure called cluster structure, which causes the glucan to be hydrophobic and to form a semicrystalline architecture of starch granules. It is known that lesions of the isoamylase1 (ISA1) gene result in accumulation of a water-soluble glucan (WSG) called phytoglycogen instead of amylopectin in various plant species. This type of cereal mutant is referred to as sugary-1 and accumulates a large amount of phytoglycogen in the endosperm. In this study, another WSG-synthesizing mutant has been isolated from japonica rice. This mutant accumulated a significant amount of WSG in the center of endosperm. No significant changes were found in activities of ISA and pullulanase and in the compositions of ISA1 homomer and ISA1-ISA2 heteromer. In addition, activities of starch branching enzyme and starch synthase isoforms were not altered. The accumulated WSG had a specific fine structure, that differed from that of phytoglycogen. Thus, we designated this new mutant as the sugary-2 mutant. Our study results strongly suggest that the Sugary-2 gene product plays an important role in amylopectin synthesis of rice endosperm and identifies a new factor that controls the normal amylopectin structure, especially at the early developmental stage of the endosperm.
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Biochemical analysis of new type mutants of japonica rice that accumulate water-soluble α-glucans in the endosperm but retain full starch debranching enzyme activities
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Autor/in / Beteiligte Person: | Satoh, Hikaru ; Sawada, Takayuki ; Nakamura, Yasunori ; Nakamura, Tetsuhiro ; Fujita, Naoko ; Utsumi, Yoshinori ; Nakagami, Tsuyoshi ; Yoshihara, Hiroki |
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Zeitschrift: | Starch - Stärke, Jg. 69 (2016-08-12), S. 1600159-1600159 |
Veröffentlichung: | Wiley, 2016 |
Medientyp: | unknown |
ISSN: | 0038-9056 (print) |
DOI: | 10.1002/star.201600159 |
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