Genetic Control of Abnormal Starch Granules and High Amylose Content in a Mutant of Glacier Barley

Nature ◽  
1969 ◽  
Vol 221 (5179) ◽  
pp. 482-483 ◽  
Author(s):  
J. T. WALKER ◽  
N. R. MERRITT
2018 ◽  
Author(s):  
Wenzhi Zhou ◽  
Shanshan Zhao ◽  
Shutao He ◽  
Qiuxiang Ma ◽  
Xinlu Lu ◽  
...  

AbstractHigh amylose starch, a desired raw material in the starch industry, can be produced by plants deficient in the function of branching enzymes (BEs). Here we report the production of transgenic cassava plants with starches containing up to 50% amylose due to the constitutive expression of hair-pin dsRNAs targeting the BE1 or BE2 genes. A significant decrease in BE transcripts was confirmed in these transgenic plants by quantitative real-time RT-PCR. The absence of BE1 protein in the BE1-RNAi plant lines (BE1i) and a dramatically lower level of BE2 protein in the BE2-RNAi plant lines (BE2i) were further confirmed by Western blot assays. All transgenic plant lines were grown up in the field, but with reduced biomass production of the above-ground parts and storage roots compared to wild type (WT). Considerably high amylose content in the storage roots of BE2i plant lines was achieved, though not in BE1i plant lines. Storage starch granules of BE1i and BE2i plants had similar morphology as WT, however, the size of BE1i starch granules were bigger than that of WT. Comparisons of amylograms and thermograms of all three sources of storage starches revealed dramatic changes to the pasting properties and a higher melting temperature for BE2i starches. Glucan chain length distribution analysis showed a slight increase in chains of DP>36 in BE1i lines and a dramatic increase in glucan chains between DP 10-20 and DP>40 in BE2i lines, compared to that of WT starch. Furthermore, BE2i starches displayed a B-type X-ray diffraction pattern instead of the A-type pattern found in BE1i and WT starches. Therefore, cassava BE1 and BE2 function differently in storage root starch biosynthesis; silencing of cassava BE1 or BE2 caused various changes to starch physico-chemical properties and amylopectin structure. We also report that remarkably high amylose content in cassava starch has been first obtained in transgenic cassava by silencing of BE2 expression, thus showing a high potential for future industrial utilization.


2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Ana Izabella Freire ◽  
Elisa de Melo Castro ◽  
Ariana Mota Pereira ◽  
Renata Ranielly Pedroza Cruz ◽  
Filipe Bittencourt Machado de Souza ◽  
...  

ABSTRACT: Popcorn (Zea mays var. everta) has a higher commercial value than common maize, in addition to being a popular food among consumers. Today, there is a constant search for cultivars with superior performance for several traits of interest in the case of popcorn, yield and popping expansion. On this basis, this project proposes to characterize progenies of popcorn with different values of expansion capacity regarding chemical composition and micromorphology. Kernels from the fifth cycle (C5) of intrapopulation recurrent selection were evaluated. The progenies were selected based on the popping expansion volume of their kernels. The kernels were quantified for amylose and analyzed for starch granule arrangement and pericarp thickness by scanning electron microscopy. Progenies with low popping expansion volume (0 and 7 mL g-1) showed amylose contents of 21.24 and 20.18%, respectively; a less compact endosperm, with individual starch granules interspaced with empty spaces; and pericarp thickness between 40.94 and 38.99 µm, respectively. By contrast, progenies with high popping expansion volume (30 and 35 mL g-1) showed amylose contents of 23.92 and 26.10%; a vitreous endosperm; more-compact starch granules without empty spaces in between; and pericarp thickness between 107.66 and 107.84 µm. Progenies with higher popping expansion volume exhibited a thicker pericarp, a high amylose percentage and a more-compact endosperm, whereas those with the lower expansion volumes showed a thinner pericarp, a lower amylose percentage and individual starch granules.


Author(s):  
Dương Thanh Thủy ◽  
Taiichiro Ookawa

The sensory and functional properties of rice are predominantly associated with its amylose content. Granule-bound starch synthase (GBSS) encoded by the Waxy (Wx) gene determines the synthesis of amylose, while starch branching enzymes encoded by Sbe genes are involved in the formation of amylopectin. Some studies have demonstrated that Wx gene is the major controller of amylose content but there are one or more modifying genes affecting the amylose content. Three markers,  microsatellite, Single – nucleotide – polymorphism (G/T SNP) in Wx gene and Single – nucleotide – polymorphism (T/C SNP) in Sbe1 gene, were tested for their association with amylose content using sixty-nine  rice accessions from twenty countries. Of the three markers, two markers in Wx gene are significantly associated with amylose content. The combination of two markers in Wx gene (haplotypes) explained 83.8% of the variation in amylose content and discriminated the three market classes of glutinous, low, intermediate and high amylose content of rice from each other. And T/C SNP in Sbe1 locus was not a suitable marker for amylose content. Keywords: marker, amylose content, Waxy gene.


2011 ◽  
Vol 9 (2) ◽  
pp. 38-44
Author(s):  
HADI WIYOTO ◽  
M. A.M. ANDRIANI ◽  
NUR HER RIYADI PARNANTO

Wiyoto H, Andriani MAM, Parnanto NHR. 2011. Study of antioxidant activity and anti-cholesterol content on red yeast rice with substrates variation (rice, corn and dried cassava). Biofarmasi 9: 38-44. Red yeast rice is one of fermented rice product by Monascus purpureus. Traditionally, the substrate used to produce red yeast rice is rice. Usually, the rice with high amylose content is proper to produce red yeast rice than low amylose. The other substrates that be used to produce red yeast rice are corn and dried cassava. The purposes of this research were to determine the effect of substrates variation (rice, corn and dried cassava) on antioxidant activity and anti-cholesterol content in red yeast rice, and to determine the substrate(s) that produce the highest antioxidant activity and anticholesterol content. The design of this research was a Completely Randomized Design with one factor, i.e. the kind of substrates: rice, corn and dried cassava, with three replications. Then, the data were analyzed with ANOVA at a level of significance α=0.05, and continued with DMRT at the same level. This results showed that the effect of substrates kind to antioxidant activity and anti-cholesterol content on red yeast rice. The rice substrate had higher antioxidant activity and anti-cholesterol content than corn and dried cassava substrates. The antioxidant activity and the anti-cholesterol content on red yeast rice from rice substrate were 45.6100% and 0.026600%, respectively. The antioxidant activity and the anti-cholesterol content on red yeast rice from corn substrate were 44.0500% and 0.022833%, respectively, while the antioxidant activity and the anti-cholesterol content on red yeast rice from dried cassava substrate were 42.8333% and 0.013200%, respectively.


2007 ◽  
Vol 90 (6) ◽  
pp. 1628-1634 ◽  
Author(s):  
Tatsuya Morita ◽  
Yusuke Ito ◽  
Ian Lewis Brown ◽  
Ryuichi Ando ◽  
Shuhachi Kiriyama

Abstract Digestibility of maize starch granules with different amylose content (AL-0, 22, 54, 68, 80, or 90) was investigated. Measurement of the in vivo resistant starch (RS) content of the starches was performed using surgically prepared ileorectostomized rats. The rats were fed a purified diet containing one of the starches at 652.5 g/kg diet. The in vivo RS content was determined based on the fecal starch excretion. The dietary fiber (DF) value increased as a function of the amylose content in the starch and showed a positive linear correlation with the gelatinization temperature of the granules. In contrast, the in vitro RS content was likely to depend on both the surface area and amylose contents of the starch granules. The maximum in vitro RS content was obtained with AL-68 (54.4). In vivo RS content showed a significant correlation with the amount of in vitro RS but not in respect to the DF detected. The in vivo RS content of AL-68 (43.4) was higher than that found in AL-90 (37.8). A profound gap was observed for AL-54 between the amount of DF (6.4) and RS (in vitro = 46.6 and in vivo = 40.9) present. The results suggest that both in vitro and in vivo digestibility of maize starch is affected by the amylose content and surface area of the granules. The current evaluation suggests that the physiological occurrence of RS from maize starch might be predictable by reference to the in vitro RS value.


Sign in / Sign up

Export Citation Format

Share Document