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In this study, we identified a gene related to plant height, leaf, and premature senescence in rice, and named it OsHLS1. Through bioinformatics analysis, it was found that this gene belongs to a new gene family-HLS family, and this gene family exists widely in higher plants. Expression of OsHLS1 was significantly brought about by gibberellin (GA). Subcellular localization showed that OsHLS1 was located in the nucleus. oshls1-3 displayed a GA-deficient phenotype, with dwarf plants. In addition, oshls1-3 also showed premature senescence, shorter and narrower leaves, and pollen abortion. Exogenous GA

The starchy kernel of Euryale ferox seed has attracted much attention because of its edible and medicinal values. In this article, physicochemical properties of E. ferox kernel starches were investigated from two different regions. Dry kernel contained about 70% starch. The starch was polyhedral in shape, had very small size of about 1~2 μm in diameter, and exhibited A-type crystallinity. The native starches of kernels from two different regions showed similar amylose content, molecular weight distribution, relative crystallinity, short-range ordered structure, swelling power, and digestion properties. The kernel starch from Weishan Lake had higher gelatinization temperature, enthalpy, and water solubility, contained higher resistant starch in gelatinized and retrograded starch, and showed higher resistant ability to acid and amylase hydrolysis than that from Shaobo Lake. These above results could help in promoting the use of E. ferox kernel as an alternative starchy source.

High-amylose cereal starches are attracting considerable attention because of their potential health benefits. In this study, the molecular structures and functional properties of high-amylose starches from a rice transgenic line and commercial maize were investigated and compared. High-amylose rice and maize starches had apparent amylose contents of 65.6 and 49.4%, respectively. Compared with high-amylose maize starch, high-amylose rice starch had amylopectin with a higher long branch-chain content and average chain length and with a lower short branch-chain content and degree of branching. High-amylose rice and maize starches exhibited C-type and C A -type crystallinity, respectively. The high-amylose rice starch had a significantly higher gelatinization temperature and lower gelatinization enthalpy, swelling power and pasting viscosity than high-amylose maize starch. High-amylose rice starch had a significantly higher resistance to acid hydrolysis and slightly higher resistance to amylase hydrolysis than high-amylose maize starch. Gelatinized and retrograded starches from high-amylose rice had significantly lower rapidly digestible starch and higher resistant starch contents than high-amylose maize starch. These results were also compared with those obtained from normal rice and maize starches. The significantly different molecular structures of rice and maize starches resulted in their different functional properties.

Native starch was isolated from ginkgo kernels, its physicochemical properties were investigated using some physical methods. Ginkgo starch granules were mostly oval in shape with a central Maltese cross and average long axis of 11 μm. Ginkgo starch contained 29.9% amylose content and exhibited an A-type crystallinity with 27.2% crystalline degree. Ginkgo starch had significantly higher gelatinization conclusion temperature, temperature range, and enthalpy than potato and rice starches. Ginkgo starch showed lower hot viscosity and higher breakdown viscosity than potato and rice starches. Ginkgo starch possessed markedly higher swelling power and resistance to α-amylase and amyloglucosidase hydrolysis than rice starch.

The crystalline and structural properties of acid-modified C-type starch from lotus rhizomes were investigated using a combination of techniques. The degradation of granule during hydrolysis began from the end distant from the hilum and then propagated into the center of granule, accompanied by loss of birefringence. The crystallinity changed from C-type to A-type via CA-type during hydrolysis. At the early stage of hydrolysis, the amylose content substantially reduced, the peak and conclusion gelatinization temperatures increased, and the enthalpy decreased. During hydrolysis, the double helix content gradually increased and the amorphous component decreased, the lamellar peak intensity firstly increased and then decreased accompanied by hydrolysis of amorphous and crystalline regions. This study elucidated that B-type allomorph was mainly arranged in the distal region of eccentric hilum, A-type allomorph was mainly located in the periphery of hilum end, and the center of granule was a mixed distribution of A- and B-type allomorphs.

Mutating or inhibiting genes encoding starch branching enzymes (SBEs) can increase the amylose content (AC) of cereals. We analyzed endosperm starches from three rice cultivars with different ACs and from transgenic lines derived from them. The transgenic lines had simultaneously inhibited SBE I and IIb genes. Compared with the starch from their wild-type parents, the starch from transgenic lines showed significantly increased apparent ACs and lamella size and decreased relative crystallinity, double helix content, and lamellar peak scattering intensity, and altered short-range ordered structure in the external region. These changes were more prominent in the line derived from the high-AC cultivar than in those derived from waxy and low-AC cultivars. Inhibiting both SBE I and IIb changed the crystalline structure of starch from A-type to CA-type in lines derived from waxy and low-AC cultivars, and from A-type to C-type in that derived from the high-AC cultivar.

High-amylose starches are attracting considerable attention because of their potential health benefits and industrial uses. Enzyme hydrolysis of starch is involved in many biological and industrial processes. In this paper, starches were isolated from mature grains of high-amylose transgenic rice line (TRS) and its wild type rice cultivar Te-qing (TQ). The morphological and structural changes of starch residues following porcine pancreatic α-amylase (PPA) hydrolysis were characterized by SEM, DSC, XRD, 13C CP/MAS NMR, and ATR-FTIR. TQ starch was hydrolyzed faster than TRS starch. PPA pitted the starch granule surface first, then penetrated into the interior and hydrolyzed the granule from the inside out. The peripheral region of subgranule and the surrounding band of TRS starch were more resistant to PPA hydrolysis than the external region of TQ starch. Both amorphous and crystalline (the long- and short-range ordered) structures were simultaneously hydrolyzed in TQ starch. A-type polymorph of TRS C-type starch was hydrolyzed faster than B-type polymorph. The long-range ordered structure was hydrolyzed faster than the amorphous structure, whereas the short-range ordered structure was hydrolyzed slower than the amorphous structure in TRS starch in the initial hydrolysis stage. The above results indicated that B-type crystallinity and short-range ordered structure in the peripheral region of subgranule and the surrounding band of TRS starch increased the resistance of TRS starch to PPA hydrolysis.

High-amylose starches are attracting considerable attention because of their potential health benefits and industrial uses. Enzyme hydrolysis of starch is involved in many biological and industrial processes. In this paper, starches were isolated from high-amylose transgenic rice (TRS) and its wild type rice, Te-qing (TQ). The morphological and structural changes of starch residues following Aspergillus niger amyloglucosidase (AAG) hydrolysis were investigated. AAG hydrolysed TQ starch from the granule surface, and TRS starch from the granule interior. During AAG hydrolysis, the content of amorphous structure increased, the contents of ordered structure and single helix decreased, and gelatinisation enthalpy decreased in TQ and TRS starch residues. The A-type polymorph of TRS C-type starch was hydrolysed faster than the B-type polymorph. The short-range ordered structure and B-type polymorph in the peripheral region of the subgranule and the surrounding band of TRS starch increased the resistance of TRS starch to AAG hydrolysis.

This study investigated the physicochemical properties of rhizome starch of A. altaica for the first time. The results were compared to those obtained from two common starches (potato and rice). The rhizome had a starch content of 49.8%. Isolated starch granules were mostly oval in shape with a central Maltese cross and an average long axis of 6.25 μm. The starch contained 35.5% amylose and had lower gelatinization and pasting temperatures than rice and potato starches and a swelling power comparable to potato. Altaica starch had high breakdown and setback viscosities. X-ray diffraction revealed B-type starch with relative degree of crystallinity of 17.5%. Starch possessed a high susceptibility to hydrolysis by acid, porcine pancreatic α-amylase and Aspergillus niger amyloglucosidase when compared with potato and rice starches.

Lotus seed and rhizome starches have been used as functional foods in east Asia for thousands of years. In this paper, starches were isolated from lotus seed and rhizome, and their physicochemical properties were compared. Seed starches were small oval granules, rhizome starches had small oval granules and large elongated granules. Seed starches showed significantly higher amylose content and gelatinization temperature and lower swelling power than rhizome starches. Seed starches exhibited an A-type X-ray diffraction pattern with higher crystalline degree, while rhizome starches showed a C-type pattern which changed from C- to A-type with gradually increasing crystalline degree during acid hydrolysis. The degree of order in starch external region was higher in rhizome than in seed. The external region structure of rhizome starches became more ordered during acid hydrolysis. Rhizome starches had higher rate of acid hydrolysis and lower rate of porcine pancreatic α-amylase hydrolysis than seed starches.

In this paper, endosperm starches were isolated from a high-amylose transgenic rice line (TRS) and its wild type rice Teqing (TQ) kernels at different developmental stages. TQ and TRS starches showed similar amylose contents and shapes at early developmental stage, then the amylose content increased with kernel development. The rate of increase in amylose content was much faster in TRS starches than that in TQ starches. TRS starches showed heterogenous granules at the middle and late developmental stages. TQ starch crystallinity remained A-type, but TRS starch crystallinity changed from A- to C- via CA-type. TRS starches showed higher gelatinization temperatures, lower gelatinization enthalpies, lower swelling powers, and lower hydrolysis rates at middle and late developmental stages compared with TQ starches. The amylose content had a significantly negative correlation with crystallinity, gelatinization enthalpy, swelling power, enzyme digestibility, and acid hydrolysis.

Starches were isolated from rhizomes of Curcuma longa, Canna edulis and Canna indica and bulbs of Lilium lancifolium, and showed a B-type X-ray diffraction pattern. Their physicochemical properties were investigated and compared. These starches showed significantly different granule morphologies and sizes, but all had eccentric hila. The C. longa starch had the lowest content of amylopectin short branch-chain and branching degree and the highest content of amylopectin long branch-chain, and the L. lancifolium starch the highest content of amylopectin short branch-chain and branching degree and the lowest content of amylopectin long branch-chain among the four starches. The L. lancifolium starch had the lowest resistance to gelatinization, and showed the lowest pasting peak, hot and final viscosities, and the C. longa starch had the highest resistance to gelatinization, and showed the highest pasting hot, final and setback viscosities and the lowest pasting breakdown viscosity. The C. longa and L. lancifolium starches possessed very high and low resistance to hydrolysis and digestion, respectively. The above physicochemical properties would be useful for the applications of B-type starches in food and nonfood industries.

Large-, medium-, and small-sized granules were separated from normal and high-amylose maize starches using a glycerol centrifugation method. The different-sized fractions of normal maize starch showed similar molecular weight distribution, crystal structure, long- and short-range ordered structure, and lamellar structure of starch, but the different-sized fractions of high-amylose maize starch showed markedly different structural properties. The amylose content, iodine blue value, amylopectin long branch-chain, and IR ratio of 1045/1022 cm(-1) significantly increased with decrease of granule size, but the amylopectin short branch-chain and branching degree, relative crystallinity, IR ratio of 1022/995 cm(-1), and peak intensity of lamellar structure markedly decreased with decrease of granule size for high-amylose maize starch. The large-sized granules of high-amylose maize starch were A-type crystallinity, native and medium-sized granules of high-amylose maize starch were CA-type crystallinity, and small-sized granules of high-amylose maize starch were C-type crystallinity, indicating that C-type starch might contain A-type starch granules.

High-amylose cereal starches usually have heterogeneous starch granules in morphological structure. In the present study, the polygonal, aggregate, elongated, and hollow starch granules were separated from different regions of the kernels of high-amylose rice, and their structures were investigated. The results showed that the polygonal starch granules had low amylose content and high short branch-chain and branching degree of amylopectin, and exhibited A-type crystallinity. The aggregate starch granules had high long branch-chain of amylopectin, relative crystallinity, and double helix content, and exhibited C-type crystallinity. The elongated starch granules had high amylose content and low branching degree of amylopectin and relative crystallinity, and exhibited C-type crystallinity. The hollow starch granules had very high amylose content, proportion of amorphous conformation, and amylose-lipid complex, and very low branch-chain of amylopectin, branching degree of amylopectin, and double helix content, and exhibited no crystallinity. The different structures of heterogeneous starch granules from high-amylose rice resulted in significantly different thermal properties.

The structures (morphology, molecule, and crystallinity) and functional properties (gelatinization, hydrolysis, and in vitro digestion) of normal rice starches with different amylose contents were investigated and their relationships were analyzed. The results showed that the morphology, granule size, and crystalline type did not significantly change among rice starches. The molecular structure (amylose content, amylopectin branch-chain content, and amylopectin branching degree) and crystalline structure (relative crystallinity, IR ratio of 1045/1022 cm(-1), lamellar peak intensity, and lamellar distance) significantly varied among rice starches, which resulted in different functional properties. The gelatinization temperature and water solubility were significantly positively correlated with amylose content but significantly negatively correlated with amylopectin short branch-chain. The swelling power, hydrolysis and in vitro digestion were significantly positively correlated with amylopectin short branch-chain, relative crystallinity, IR ratio of 1045/1022 cm(-1), and lamellar peak intensity but significantly negatively correlated with amylose content and lamellar distance.

The allomorph distribution and granule structure of C-type starch from lotus rhizomes were investigated using a combination of techniques during gelatinization. The disruption of crystallinity during gelatinization began from the end distant from the eccentric hilum and then propagated into the center of granule. The periphery of hilum end was finally gelatinized, accompanied by high swelling. The crystallinity changed from C-type to A-type via C A -type during gelatinization, and finally became amorphous structure. The amylose content, crystal degree, helix content, ratio of 1045/1022 cm −1 , and peak intensity of crystalline lamellae of gelatinizing starch significantly decreased after 70 °C. The amorphous content and ratio of 1022/995 cm −1 increased after 70 °C. This study elucidated that B-type allomorph was mainly arranged in the distal region of eccentric hilum, A-type allomorph was mainly located in the periphery of hilum end, and the center of granule was a mixed distribution of A- and B-type allomorphs.

Native starches were isolated from mature grains of high-amylose transgenic rice TRS and its wild-type rice TQ and treated with 0.1% and 0.4% NaOH for 7 and 14 days at 35 °C. Alkali-treated starches were characterised for structural and functional properties using various physical methods. The 0.1% NaOH treatment had no significant effect on structural and functional properties of starches except that it markedly increased the hydrolysis of starch by amylolytic enzymes. The 0.4% NaOH treatment resulted in some changes in structural and functional properties of starches. The alkali treatment affected granule morphology and decreased the electron density between crystalline and amorphous lamellae of starch. The effect of alkali on the crystalline structure including long- and short-range ordered structure was not pronounced. Compared with control starch, alkali-treated TRS starches had lower amylose content, higher onset and peak gelatinisation temperatures, and faster hydrolysis of starch by HCl and amylolytic enzymes.

High-amylose cereal starch has a great benefit on human health through its resistant starch content. In this paper, starches were isolated from mature grains of high-amylose transgenic rice line (TRS) and its wild-type rice cultivar Te-qing (TQ) and digested in vitro and in vivo. The structural changes of digestive starch residues were characterized using DSC, XRD, (13)C CP/MAS NMR, and ATR-FTIR. TQ starch was very susceptible to digestion; its residues following in vitro and in vivo digestion showed similar structural characteristics with TQ control starch, which suggested that both amorphous and crystalline structures were simultaneously digested. Both amorphous and the long-range order structures were also simultaneously hydrolyzed in TRS starch, but the short-range order (double helix) structure in the external region of TRS starch granule increased with increasing digestion time. The A-type polymorph of TRS C-type starch was hydrolyzed more rapidly than the B-type polymorph. These results suggested that B-type crystallinity and short-range order structure in the external region of starch granule made TRS starch resistant to digestion.

High-amylose cereal starch has a great benefit on human health through its resistant starch (RS) content. Enzyme hydrolysis of native starch is very helpful in understanding the structure of starch granules and utilizing them. In this paper, native starch granules were isolated from a transgenic rice line (TRS) enriched with amylose and RS and hydrolyzed by α-amylase. Structural properties of hydrolyzed TRS starches were studied by X-ray powder diffraction, Fourier transform infrared, and differential scanning calorimetry. The A-type polymorph of TRS C-type starch was hydrolyzed faster than the B-type polymorph, but the crystallinity did not significantly change during enzyme hydrolysis. The degree of order in the external region of starch granule increased with increasing enzyme hydrolysis time. The amylose content decreased at first and then went back up during enzyme hydrolysis. The hydrolyzed starches exhibited increased onset and peak gelatinization temperatures and decreased gelatinization enthalpy on hydrolysis. These results suggested that the B-type polymorph and high amylose that formed the double helices and amylose-lipid complex increased the resistance to BAA hydrolysis. Furthermore, the spectrum results of RS from TRS native starch digested by pancreatic α-amylase and amyloglucosidase also supported the above conclusion.

High-amylose cereal starch has a great benefit on human health. Acid modification is very helpful for application of high-amylose starch in food and non-food industries. In this study, the ordered structure of acid-modified high-amylose rice starch was investigated by GPC, HPAEC, 13 C CP/MAS NMR and XRD. Acid preferentially degraded the amylose, then A chain and short B chain of amylopectin. Relative double helix content and crystallinity both initially increased sharply and then progressively with acid hydrolysis. The relative crystallinity of starches obtained from 13 C CP/MAS NMR was higher than that from XRD. The onset gelatinisation temperature decreased, while the peak and conclusion temperatures increased with increasing hydrolysis time. The endothermic value initially increased and then decreased with acid hydrolysis. The swelling power decreased while solubility increased after acid hydrolysis. These results add to our understanding of the effect of acid hydrolysis on the high-amylose rice starch.