Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
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Enzyme
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Query: UMLS:C0028754 (
obesity
)
124,988
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Changes in human lifestyle and food consumption have resulted in a large increase in the incidence of type-2 diabetes,
obesity
, and colon disease, especially in Asia. These conditions are a growing threat to human health, but consumption of foods high in resistant starch (RS) can potentially reduce their incidence. Strategies to increase RS in rice are limited by a lack of knowledge of its molecular basis. Through map-based cloning of a RS locus in
indica
rice, we have identified a defective soluble
starch synthase
gene (
SSIIIa
) responsible for RS production and further showed that RS production is dependent on the high expression of the
Waxy
a
(
Wx
a
) allele, which is prevalent in
indica
varieties. The resulting RS has modified granule structure; high amylose, lipid, and amylose-lipid complex; and altered physicochemical properties. This discovery provides an opportunity to increase RS content of cooked rice, especially in the
indica
varieties, which predominates in southern Asia.
...
PMID:Critical roles of soluble starch synthase SSIIIa and granule-bound starch synthase Waxy in synthesizing resistant starch in rice. 2779 Nov 74
Resistant starch (RS) is beneficial to human health. In order to reduce the current prevalence of diabetes and
obesity
, several transgenic and mutant crops containing high RS content are being developed. RS content of steamed rice with starch-branching enzyme (BE)IIb-deficient mutant endosperms is considerably high. To understand the mechanisms of RS synthesis and to increase RS content, we developed novel mutant rice lines by introducing the gene encoding
starch synthase
(SS)IIa and/or granule-bound starch synthase (GBSS)I from an indica rice cultivar into a japonica rice-based BEIIb-deficient mutant line, be2b. Introduction of SSIIa from an indica rice cultivar produced higher levels of amylopectin chains with degree of polymerization (DP) 11-18 than those in be2b; the extent of the change was slight due to the shortage of donor chains for SSIIa (DP 6-12) owing to BEIIb deficiency. The introduction of GBSSI from an indica rice cultivar significantly increased amylose content (by approximately 10%) in the endosperm starch. RS content of the new mutant lines was the same as or slightly higher than that of the be2b parent line. The relationship linking starch structure, RS content, and starch biosynthetic enzymes in the new mutant lines has also been discussed.
...
PMID:Characterization of the endosperm starch and the pleiotropic effects of biosynthetic enzymes on their properties in novel mutant rice lines with high resistant starch and amylose content. 2833 May 63
