Interaction betweenamylose,fattyacid,andβ-lactoglobulinto study multiplebiomacromoleculesself-assemblyandapplication

New concept for the development of supramolecular assemblies from intricate inter-actions between different classes of biomacromolecules(polysaccharides,proteins and lipids)is yet to come,due to their intrinsic chemical and structural complex-ity and incompatibility.Herein,we report an interaction mechanism among multiple biomacromolecules,and the structural and digestive properties of their assemblies using amylose(AM),lauric acid(LA),andβ-lactoglobulin(βLG)as exemplars.AM,LA,andβLG interact to form a water-soluble ternary complex through van der Waals forces between AM and LA and high affinity binding between AM andβLG,which can further assemble into uniform-sized,semi-crystalline nanospheres under certain thermodynamic conditions.These nanospheres are substantially resis-tant to amylolysis,thus can be well utilized by gut microbiota,including increasing short-chain fatty acid levels and shaping bacterial communities.Illustrating the com-plexation of AM,LA,andβLG and their assemblies from disorder to order,this work offers potential rationale of assemblies for multiple biomacromolecules driven by non-covalent interactions and substantial potentials for supramolecular biomaterials development.

Correlation Analysis of Characters of Indica Hybrid Rice with High Content of Amylose

[Objective] The aim was to research and analyze characters and related correlation of indica hybrid rice containing high amylose. [Method] In the research, major characters of 16 species of groups of {ndica hybrid rice and the correlation were explored in rice belts in Sichuan in 2011. [Result] The variation of chalkiness degree was the highest at 26.8%, followed by rate of head rice at 22.89%; varia- tions of head rice rate and chalkiness degree were lower at 0.72% and 2.61%. In addition, rate of unpolished rice was of significantly negative correlation with chalki- ness degree; rate of chalky rice was of extremely positive correlation with chalkiness degree and gel consistency; chalkiness degree was of significantly positive correla- tion with gel consistency; gel consistency was of significantly negative correlation with protein content; amylose content was of insignificant correlation with gel consis- tency （r=0.166 9） of the 16 hybrid groups. These indicated that gel consistency would be still high as the content of amylose grows （AC≥25%）. For example, when the content of anylose in Chuanxiang 29A/Luhui 37, Kangfeng AJ6684, and Lefeng A/SR536 exceeded 27%, the gel consistency was over 80 mm in the research. [Conclusion] The research provides references for improvement of amylose content in breeding hybrid rice.

Correlation of Simple Sequence Repeat (SSR) Variants in the Leader Sequence of the waxy Gene with Amylose Content of the Grain in Rice

Variation of two simple sequence repeats (SSRs) in the leader region of the waxy gene was analyzed in a sample of 74 accessions, including Oryza sativa L. ssp. indica, japonica and wild rice (O.rufipogon) representing a wide distribution range of amylose content (AC) in cultivated rice. Eight alleles were detected in the (CT) n motif and two alleles were resolved in the (AATT) n motif. The distribution of the alleles of the two SSRs was quite uneven as detected by the (CT) n motif. The repeat numbers of the two SSR motifs, (CT) n and (AATT) n, appeared to be inversely related such that the total length of this region was maintained. AC of the varieties was highly correlated with the length of SSRs. Differences in AC among the various SSR genotypes were statistically highly significant as analyzed using genotypes of both SSR motifs. Although the SSR variation did not seem to have obvious function in the synthesis of the starch synthase encoded by the waxy gene, the almost perfect correlation between the two SSRs and AC level could be used for quality improvement in rice breeding programs.

Effect of Fast Neutron Irradiation on Amylose Content and Amylopectin Structure of Thailand Rice Cultivar Jao Hom Nin

[Objective]The aim was to research the effect of fast neutron irradiation on amylose content and amylopectin structure.[Method] The amylose content and amylopectin structure of the M4 plants of Thailand rice cultivar Jao Hom Nin irradiated with fast neutron at 13 Gy were evaluated and analyzed in this paper.[Result]The results showed that amylose content of rice could be changed by fast neutron irradiation,many rice mutants with reduced amylose content and many others with enhanced amylose content even some mutants with amylose content near to waxy rice could be isolated,but fast neutron irradiation almost had no effect on amylopectin structure of the samples.[Conclusion]The study provided a basis for breeding rice cultivar with different amylose content in order to meet with the taste hobby of different people and the further processing of diverse rice products via the irradiation of fast neutron.

The effect of amylose on kernel phenotypic characteristics,starch-related gene expression and amylose inheritance in naturally mutated high-amylose maize

High-amylose maize starch has great pote ntial for widespread in dustrial use due to its ability to form strong gels and film and in the food processi ng field,thus servi ng as a resista nt starch source.However,there is still a substa ntial shortage of high-amylose maize due to the limitation of natural germplasm resources,although the well-known amylose extender(ae)gene mutants have bee n found to produce high-amylose maize lines since 1948.In this con text,high-amylose maize lines(13 inbreds and 18 hybrids)originating from a natural amylose mutant in our testing field were utilized to study the correlation between amylose content(AC)and phenotypic traits(kernel morphology and endosperm glossiness),grain filling characteristics,gene expression,and amylose inheritanee.Our results showed that AC was negatively correlated with total starch con tent but was not correlated with grain phe no types,such as kernel full ness,kernel morphology and endosperm glossiness.Maize lines with higher amylose had a greater grain filling rate than that of the controI(B73)during the first 20 days after pollination(DAP).Both starch debranching enzyme(DBE)groups and starch branching enzyme lib(SBEIIb)groups showed a greater abundance in the control(B73)than in the high-amylose maize lines.Male parents directly predicted AC of Fv which was moderately positively correlated with the F2 generation.

Advances in Breeding of High-amylose Indica Hybrid Rice Combinations in Sichuan Province

During 2000-2013, totally ten high-amylose specific hybrid rice combinations approved and five combinations for production test were bred in Sichuan Province. In the paper, rice yield, economic traits, quality indicators and rice blast-resistance identification results of these 15 hybrid combinations were described and analyzed. Results show that Chuanxiangyou37 and Tianlongyou540 have relatively high amylose content, good yielding ability, high resistance and appropriate growth period, which are new hybrid rice varieties with organic combination of high amylase content, high gel consistency, high yield, stable yield and wide adaptability. Therefore, Chuanxiangyou37 and Tianlongyou540 are recommended as the main combination for rice production.

Determination of Amylose Content and Its Relationship with RVA Profile Within Genetically Similar Cultivars of Rice(Oryza sativa L.ssp.japonica)

Anther culture pure lines with antisense Wx gene were generated by Agrobacterium tumefaciens-mediated co-transformation followed by anther culture in transgenic rice （Oryza sativa L. ssp. japonica）. The antisense Wx transgenic pure lines were used to analyze the differences and the relationship between RVA eigenvalues among the lines with different amylose contents. 77 pure lines of anther culture having antisense Wx gene were studied for the amylose content of its offspring cultivar, Wuyunjing 7. It was found that levels ofamylose content were similar to the control in 19 lines （16.0%）; 1-5% lower than control in 50 lines, of which, within 11.0-13.9% in 40 lines; and 3.1-4.0% in 8 lines. The effect of the amylose content on RVA eigenvalue was analyzed through the RVA profile graphic comparison and test of significance for RVA eigenvalues. The analysis of RVA profiles with different amylose contents indicated that there were two kinds of RVA profiles within genetically similar cultivars. The lines with 3.1-4.0% of amylose content were distinctly different from other lines and conventional glutinous rice. The comparison of the similarity curve of RVA profile of the lines with different amylose contents showed that the lines with lower amylose content had a distinguished RVA profile with the curve increasing gradually, but not exceeding the first apex. The test of significance for eigenvalues of the RVA profile in the lines with different amylose contents indicated that there were five eigenvalues remarkably different among the lines with 3.1-4.0% of amylose content compared with other two groups. Further, there were three eigenvalues remarkably different among the lines with 11.0-13.5% of amylose content compared with control group. An optimized mathematical model, which characterizes the relationships between the amylose content and RVA eigenvalue, has been established in this study. From this model, it was clearly indicated that the parameters PeT and SBV were more related to amylose content. It was concluded that the differences in amylose content not only affected the eigenvalues of RVA but also caused different RVA profiles within genetically similar cultivars. The introduction of antisense Wx gene could lead to reduce the amylose content and lay theoretical foundation for quality improvement in rice breeding programs.

Expression Profiles and Protein Complexes of Starch Biosynthetic Enzymes from White-Core and Waxy Mutants Induced from High Amylose Indica Rice

Physicochemical properties of endosperm starches in milled rice determine its cooking and eating quality.Amylose is synthesized by granule-bound starch synthase I(GBSSI),whilst amylopectin is synthesized by the synergistic activities of starch synthases(SSs),branching enzymes(BEs)and debranching enzymes(DBEs).However,the complexes formed by starch biosynthetic enzymes are not well characterized.Gene expression profiles and protein complexes were determined in white-core(GM645)and waxy(GM077)mutants derived from a high amylose indica rice Guangluai 4(GLA4).In GM645,genes including AGPS1,GBSSI,SSIIa,BEI,BEIIa,BEIIb,PUL,ISA1 and SP were significantly downregulated during seed development.In GM077,the expression levels of AGPL2,AGPS1,AGPS2b,SSIIIa,BEI,PUL and ISA1 were significantly upregulated.Co-immunoprecipitation assays revealed interactions of SSs-BEs,SSs-PUL and BEs-PUL in developing seeds.However,weak SSI-SSIIa interaction was detected in GM077,whilst SSI-PUL interaction was absent.Weak interaction signals for SSI-SSIIa,SSIIa-BEI,SSIIa-BEIIb,BEI-BEIIb and SSI-BEI were also observed in GM645.These results suggest that the protein-protein interactions for starch biosynthesis are modified in mutants,which provides insight into the mechanisms of starch biosynthesis,particularly in indica rice.

Application of Near Infrared Transmittance Spectroscopy(NITS)in Determining Amylose Content of Rice Grain

Rice samples were scanned with a Foss Tecator Infratec and their amylose content was determinedusing a standard wet chemical method.Calibration software along with several mathematicaltreatments of the sample spectra and several regression methods was used to optimize a nearinfrared transmittance spectroscopy equation for determining rice amylose content. The standarderror of calibration, standard error of cross-validation and regression squared of thecalibration were 1.489, 1.761 and 0.885,respectively.

Progresses in Researches of the Application of Low-Amylose Content Rice Gene for Breeding

Amylose content is a key determinant of eating quality of rice. With the characteristics offluffy texture, glossy appearance when cooked, remaining soft when cooled and excellentpuffing ability, the low-amylose rice with amylose content 5-15% could be served as not onlycooked rice directly, but also good material for convenience, mixed rice and puffing foods.Current status on characterization, inheritance, molecular mechanism and breeding of low-amylose content rice was reviewed in this paper, strategy of related researches in the era ofglymics was mainly discussed furthermore. The future research should focus on screening andenhancing the germplasm, further elucidating the molecular mechanism on mutation of lowamylose content, utilizing the genes independent of Wx on low-amylose content rice breedingprogram, and developing high quality functional rice cultivars for special usage throughpyramiding low amylose gene and other special quality genes.

Comparison of Near Infrared Spectroscopy Models for Determining Protein and Amylose Contents Between Calibration Samples of Recombinant Inbred Lines and Conventional Varieties of Rice

The near infrared spectra of 178 recombinant inbred lines （RILs） from the cross of Ⅱ-32B/Yuezaoxian 6 （YZX6） and 511 varieties in rice were acquired. A total of 80 RILs and 96 cultivars were selected as modeling samples by comparing the spectra similarity primarily. Three partial least square （PLS） regression models were developed, based on the RILs （RIL-model）, the varieties （Var-model） and their mixture （Mix-model）, for protein content （PC） and amylose content （AC）, respectively. Cross validation and outer prediction showed that the models were largely influenced by the range and distribution of modeling samples. The regression model of PC based on the cultivars and the model of AC based on RILs had higher coefficient of determination （r^2 ≥ 0.9） and lower root mean square error of cross validation （RMSECVs）. The disadvantages of RIL samples for PC model and variety samples for AC model were probably caused by the narrow range of variance. Aberrant predictions were obtained for outer sample with PC or AC outside the range or within the distribution gap of modeling samples. The Mix-models gave more reliable prediction as the distribution of RIL and variety modeling samples were complementary to each other.

Determination of Rice Amylose Content by Near-infrared Spectroscopy

Amylose contents in 298 rice samples were determined by conventional method, and a near-infrared spectral model of rice amylose content was established by partial least squares. The calibration determination coefficient （RC） was 0.95; the standard error of calibration （SEC） was 1.58; and the determination coefficient of cross validation （RP） was 0.91, and the standard error of prediction SEP was 1.92. External validation was performed with 20 samples, the predicted values and the determined values were not significantly different, and the correlation coefficient between them was over 95%. The calibration model has good prediction perfor- mance, and could rapidly determine rice amylose content instead of chemical ana- lytical method.

Effects of dietary amylose to amylopectin ratio on growth performance,carcass quality characteristics and meat fatty acids in Chinese Qinchuan cattle

This study evaluated the effects of the dietary starch amylose/amylopectin ratio on growth performance,rumen fermentation and blood parameters,carcass characteristics and marbling score,and meat fatty acid profiles and transcriptional changes in the genes involved in the gluconeogenesis pathway in Chinese Qinchuan cattle.Forty-five cattle were randomly divided into three groups.The bulls were fed a control diet(middle amylose/amylopectin ratio=0.47)or diets with either waxy corn starch(WS)inclusion(low amylose/amylopectin ratio=0.23)or pea starch(PS)inclusion(high amylose/amylopectin ratio=0.60)for 90 days.The bulls were individually allowed to receive the diets at the daily amount of at least 2.1%of their individual BW twice daily.The bulls were weighed at 45-day intervals,and blood and rumen fluid samples were also collected at 45-day intervals.The bulls were slaughtered and longissimus thoracis(LT)samples were collected for meat quality measurements.Compared with PS,the average daily gain(ADG)and feed efficiency in control and WS were increased(P<0.05)during d 0 to 45.However,the feed efficiency in PS was increased(P<0.05)compared with the control and WS during d 46 to 90.During the whole feeding trial,the ADG in control and WS showed trends that were higher(0.05<P<0.1)than that of PS,while other growth performance measures and feed intake did not differ(P>0.05)among the three groups.Compared with PS,the serum insulin concentration in WS was increased(P<0.05)at d 45,but not at d 90.Compared with control and WS,the serum SOD and T-AOC concentrations in PS were increased(P<0.05)at d 45,but not at d 90.Compared with control,the rumen microbial crude protein contents in WS and PS were increased(P<0.05)at d 0,while those of control and WS were higher(P<0.05)than that of PS at d 45,but not at d 90.Compared with PS,the backfat thickness in control and WS were increased(P<0.05),however,the marbling score and expression of genes related to the gluconeogenesis pathway in liver of the three groups did not differ(P>0.05).Chemical and physio-chemical compositions of LT did not differ(P>0.05)among the three groups.In conclusion,diets with low or middle amylose/amylopectin ratios increased the backfat thickness,and tended to improve ADG,but had no effect on other carcass characteristics,fat content in the LT,or the expression of hepatic genes related to the gluconeogenesis pathway in Chinese Qinchuan cattle.

Relationship Between the First Base of the Donor Splice Site of Waxy Gene Intron 1 and Amylose Content in Yunnan Indigenous Rice Varieties

There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT- genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content （18.95% on average） than those with TT- genotype （all below 16%）, but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 （P〈0.01）.

Amylose Content and Starch Granule Size in Rice Grains are Affected By Growing Season

Amylose content and starch granule size in grains influence rice quality,which differs between the early(ES)and late season(LS).The objective of this study was to determine the variation of amylose content and starch granule size between seasons and find the main reasons(e.g.,temperature and solar radiation)for the observed variation.Field experiments with six rice varieties(three high and three low amylose content rice)planted in the ES and LS were conducted in 2016 and 2017,respectively.The mean temperatures during the filling stage were higher in ES,however,the daily temperatures at 7-10 days after flowering(DAF)in 2016,and at 5-10,13-14 DAF in 2017 were higher in LS.The results showed that amylose content in LS was lower than in ES with high amylose content rice varieties(HACV);the opposite trend occurred with low amylose content rice varieties(LACV).The mean starch granule diameter was higher in LS than ES in 2016,but the opposite result occurred in 2017 with all rice.Our results suggest that higher temperatures increased and decreased the amylose content in HACV and LACV,respectively.Temperatures at 5-15 DAF were important for the formation of starch granules:lower temperatures during 10-14 DAF increased the proportion of larger starch granules(d>6.21μm,some with d>13.3μm),and higher temperatures at 5-6 DAF increased the proportion of starch granules with diameter 4.24-6.21μm.

Insights into the swelling process and drug release mechanisms from cross-linked pectin/high amylose starch matrices

Cross-linked pectin/high amylose mixtures were evaluated as a new excipient for matrix tablets formulations,since the mixing of polymers and cross-linking reaction represent rational tools to reach materials with modulated and specific properties that meet specific therapeutic needs.Objective:In this work the influence of polymer ratio and cross-linking process on the swelling and the mechanism driving the drug release from swellable matrix tablets prepared with this excipient was investigated.Methods:Cross-linked samples were characterized by their micromeritic properties(size and shape,density,angle of repose and flow rate)and liquid uptake ability.Matrix tablets were evaluated according their physical properties and the drug release rates and mechanisms were also investigated.Results:Cross-linked samples demonstrated size homogeneity and irregular shape,with liquid uptake ability insensible to pH.Cross-linking process of samples allowed the control of drug release rates and the drug release mechanism was influenced by both polymer ratio and cross-linking process.The drug release of samples with minor proportion of pectin was driven by an anomalous transport and the increase of the pectin proportion contributed to the erosion of the matrix.Conclusion:The cross-linked mixtures of high amylose and pectin showed a suitable excipient for slowing the drug release rates.

Amylose Content,Morphology,Crystal Structure,and Thermal Properties of Starch Grains in Main and Ratoon Rice Crops

Rice ratooning,or the production of a second rice crop from stubble after the harvest of the main crop,is considered to be a green and resource-efficient rice production system.The present study was conducted to examine variance in amylose content(AC),grain morphology,crystal structure,and thermal properties of starch between main-and ratoon-season rice of seven varieties.Ratoon-season rice grains had higher ACs and significantly lower transition gelatinization temperatures(To,Tp,and Tc)than did main-season rice grains.The relative crystallinity and lamellar peak intensity of ratoon-season rice starch were 7.89%and 20.38%lower,respectively,than those of main-season rice starch.In addition,smaller granules with smoother surfaces and lower thermal parameters were observed in the starch of ratoon-season rice.The relative crystallinity and lamellar peak intensity of starch correlated negatively with the AC and positively with transition gelatinization temperatures.These results suggest that the superior cooking quality of ratoon-season rice is attributable to the moderate increase of grain AC,which reduces the relative crystallinity,weakens the crystal structure,and lead to a decrease in the gelatinization temperature.

Molecular marker for screening rice cultivars with intermediate amylose content in indica

The waxy(Wx)gene of rice encodes the granule-bound starch synthase(GBSS),which was required in the synthesis of amylose in endosperm.Theamylose content(AC)of rice endosperm played an important role in grain yield,palatability,and processing quality.Our previous researehes showed that en-dosperm AC and GBSS contents were correlated with the ability of excising intron1 from the leader sequence of the Wx transcript.Cultivars with high endosperm

Lowering Grain Amylose Content in Backcross Offsprings of indica Rice Variety 057 by Molecular Marker-Assisted Selection

To lower the amylose content （AC） of the indica rice restorer line 057 with high AC, backcrosses were made respectively by using four indica varieties （R367, 91499, Yanhui 559, Hui 527） as low AC donor parents and 057 as the recurrent parent. A molecular marker （PCR-Acc Ⅰ） was used to identify the genotypes （GG, TT and GT） of the waxy （Wx） gene. Plants with GT genotype were selected and used as female parent and crossed with 057 to advance generation. The ACs of rice grains harvested from plants with different Wx genotypes were measured and compared to analyze the efficiency of marker-assisted selection. The ACs of the rice grain, harvested from the plants of Wx genotypes GG, GT and TT, were higher than 20%, in the range of 17.7-28.5%, and less than 18%, respectively. The PCR-Acc Ⅰ marker could be used for efficiently lowering the AC of 057 through backcrossing, and there were some influence of parental genetic background on the AC of rice grains with the same Wx genotype.

The Optical and Two-Photon Properties of Amylose-Encapsulated Chromophore

Encapsulation of DASP （4-[4-（dimethylamino）styryl]-l-octylpyridinium bromide） with amylose, and conformational transitions of amylose upon complexation with the dyes were investigated using UV-vis, fluorescence and two-photon absorption properties in various Dimethyl Sulfoxide （ DMSO）/H20 mixtures. Encapsulation of the dye was achieved by dilution of DMSO stock solutions of the chromophores （1 x 10^-3 M） and amylose （1 x 10^-1 M） with DMSO, followed by a dropwise addition of H20 with continuous stirring at room temperature. At less than 40% aqueous DMSO solutions, the chromophores had a stable encapsulation with amylose and showed over 100 times the fluorescence intensity of non-encapsulated chromophores. Both of the dye solution with and without amylose also exhibit 2PA （two-photon absorption）, as determined by nonlinear absorption measurements using 10 ns laser pulses at 800 nm. The respective values of two-photon cross-sections are 13.3 x 10.20 for encapsulated dye solution and 2.53 x 10.20 cma/GW for non encapsulated dye solution. The data clearly indicate that the contribution of the encapsulated dye dominates the two-photon absorption cross-section of the non encapsulated dye at 800 nm.