• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.16-18
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• 1986

This experiment was conducted to know the genetic nature of waxy and fractured starch endosperm genes in 1983. F$_2$ seeds involve simple recessive gene(1：3) for the waxy and fractured starch endosperm genes, respectively. Also, association between waxy and fractured starch endosperm have shown to be segregated as expected to fit in the ratio 9：3：3：1 respectively of normal-nonwaxy： fractured-nonwaxy： normal-waxy： fractured-waxy showing the acceptable value of X$^2$ test of independence.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.637-645
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• 1991

Physicochemical factors affecting cooking and eating quality of rice and their mechanisms were investigated. The stickiness of cooked rice was negatively correlated with amylose content(r=0.58, p<0.05) and protein content(r=-0.72, p<0.01), but not affected by crude fat content of rice. The ultrastructure of cooked rice grain showed the progressive gelatinization of starch from the periphery toward the center of the endosperm as water and heat energy diffused into. The rate of water diffusion appears to be dependent on the cell arrangement in the endosperm and the protein content of milled rice. Once water and heat reach the starch granules, the rate of in situ gelatinization of starches appears to be dependent on their own gelatinization temperature range and amylose content. Protein acts as a barrier for the swelling of starch and water diffusion in two ways : 1) by encasing starch granules in the starchy endosperm, and 2) by forming a barrier between the subaleurone layer and the starchy endosperm. Therefore, the separation and fragmentation of the outermost layers of the endosperm occurred more easily in the low-protein content rices, and was associated with increases of solids lost in cooking-water at 95$^{\circ}C$ and stickiness of cooked rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.63-72
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• 1994

The relationships among the endosperm structure, physicochemical characteristics and cooking and milling properties were examined in this study by using the isogenic lines which have the same genetic background except starch characteristics. The isogenic lines were bread by combining three pairs of genes, of waxy or non-waxy, fractured or round starch granule, and shrunken or plump endosperm. Although grains weight and chemical compositions of the endosperms did not differ widely, but cooking qualities, amylose contents, $\beta$-glucan viscosities were significant differences between isogenic types. Water absorptions and expansibilities were highest in waxy lines, and lowest in fratured starch granular lines; the smaller the seed sizes were, the higher the water absorptions were. Mixogram pattern of cooked barley varied with the starch properties and milling properties were excellent in fractured granular lines, whereas those properties of the waxy and shrunken endosperm lines were not good.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.227-232
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• 2008

Drought stress is one of the major abiotic stresses in agriculture worldwide. We report here a proteomic approach to investigate the impact of post-fertilization drought on grain quality in rice seed endosperm (Oryza sativa cv. IR-64). Plants were stressed for 4 days at 3 days before heading. Total proteins of endosperm were extracted and separated by two-dimensional gel electrophoresis. Not many protein spots showed differential accumulation in drought-stressed samples. More than 400 protein spots were reproducibly detected, including three that were up-regulated and five down-regulated. Mass spectrometry analysis and database searching helped us to identify six spots representing different proteins. Functionally, the identified proteins were related to protein synthesis and carbohydrate metabolism, such as Granule-Bound Starch Synthase (GBSS, Wx protein), which is thought to play a very important role in starch biosynthesis and quality, a very crucial factor in determining rice grain quality.

• Journal of Plant Biotechnology
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• v.3 no.3
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• pp.151-157
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• 2001

In order to breed barley lines with reduced viscosity of wort, a fractured starch mutant of naked barley cultivar, Nubet, was obtained from the M2 seeds mutated by the diethyl sulfate treatment. Seeds of this fractured starch mutant were opaque and the endosperm consists of angular, irregular and fractured starch. The mutant was caused by single recessive mutation and assigned by the symbol fra. The gene was located on chromosome 4, distal in long arm by linkage recombinations using translocation homozygote lethal test set. The linkage value between the fractured starch mutant and 72-4a, 72-4d were 26.0$\pm$4.9, 34.2$\pm$3.1 percent respectively. In addition to the reduced seed size, fewer kernels per spike and higher tillering ability, lower $\beta$-glucan viscosity and higher lysine content of the grain were associated with this mutant. $\beta$-glucan viscosity of the Nubet grains increased from 3 weeks after anthesis to matury and most of the viscose substances appeared to be stored in the middle of the endosperm tissue. Since the mutant grains showed better milling property as compared to Nubet, it can be used as breeding resources to develope new barley cultivars for maltins and milling purpose.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.69-74
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• 1987

These studies were conducted to investigate the changes in carbohydrate properties of the endosperm during the stages of maturity. Original moisture continued to decrease while 1,000-kernel weight and test weight increased steadily in all varieties with maturation. Starch content of the endosperm increased continuously by 35 to 40 days after heading. The B-type starch granules synthesis of the the early mature variety, Chokwang, was depressed at the later stages of development. Amylose and amylopectin components of starch both increased as the kernel matured, and amylose-amylopectin ratio also increased during the same period. Amount of pentosan per kernel basis increased throughout the maturation period. Amylograph break-down had a highly negative coefficient correlation with starch and pentosan content of endosperm. Results indicated that wheat maturation was characterized by an increase in the starch and pentosan content of the kernel.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.1-10
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• 2010

Five mutants were investigated at the molecular level to determine the factors responsible for mutated endosperm types. They were classified as high (HA) or low amylose (LA) phenotypes based on the amylose content in endosperm. The five were previously produced from Ilpum and Shindongjin cultivar treated with N-methyl-N-nitrosourea and gamma-ray irradiation, respectively. Analysis of the genomic structure and expression of Granule-bounded Starch Synthase I (GBSSI) genes revealed that mutants generally showed a higher incidence of nucleotide transition than transversion, and the $A:T{\rightarrow}G:C$ transition was particularly prevalent. The rates of nucleotide substitution in HA mutants were generally higher than those in the LA mutants, leading to higher substitutions of amino acid in the HA mutants. Neither nucleotide substitutions interfering with intron splicing or causing early termination of protein translation were found, nor any large-sized deletions or additions were found in all the mutants. In principle, amylose content can be regulated by three factors: internal alterations of GBSSI protein, the strength of gene expression, and other unknown external factors. Our results indicate that the endosperm mutants from Shindongjin arose from internal alterations of GBSSI proteins, which may be the result of amino acid substitutions. On the other hand, the Ilpum mutants might be principally caused by the alteration of gene expression level. Analysis of another three glutinous cultivars revealed that the major factor leading to glutinous phenotypes is the 23-bp duplicative motif (5'-ACGGGTTCCAGGGCCTCAAGCCC-3') commonly found in exon 2, which results in the premature termination of protein translation leading to the production of a non-functional GBSSI enzyme.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.379-383
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• 1996

The ultrastructure of the compound starch granules and the protein bodies of Odaebyeo rice of early matured variety were examined by light microscope and electron microscope. The endosperm cell appealed rectangular or octangular shape on the cross section. The thickness of cell wall containing of membraneous materials was about $0.5\;{\mu}m$ in diameter. The starch cell was filled compactly with globular or oval shaped compound starch granules with the size of $20{\sim}25\;{\mu}m$ in diameter. The compound starch granules were consisted of central core starch granule and concentrical $2{\sim}3$ layers of starch granules. The average thickness of the starch granules were about $5\;{\mu}m$. Most protein bodies were found in the aleurone layer The globular protin bodies were scattered near the compound starch granules and $2.5{\sim}3\;{\mu}m$ in diameter. The protein bodies composed of central electron dense materials and peripheral electron loose materials in limiting membrane.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.138-142
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• 1999

An experiment was carried out to find out the changes in morphology, sugars, and $\alpha$-amylase activity during the priming of rice seeds (Oryza sativa L. cv. ＇Ilpumbyeo＇). For priming, seeds were soaked in -0.6 MPa PEG solution at 15$^{\circ}C$ for 4 days (properly primed) and at $25^{\circ}C$ for 4 and 10 days (over-primed) and dried at room temperature. The size of coleoptile and differentiated leaves of properly primed seeds were bigger and coleoptile was separated from the other part of embryo compared with non-primed and over-primed seeds. As priming of seeds advanced, compound starch grains in the endosperm disintegrated into tiny starch granules, and small holes were found in the tiny starch granules and a cavities developed between embryo and endosperm. The radicle and plumule of properly primed germinating seeds developed faster than non-primed and overprimed germinating seeds. Sucrose, maltose, and raffinose contents of properly primed seeds decreased, while content of glucose and fructose and $\alpha$-amylase activity increased. However, sugar content and $\alpha$-amylase activity of over-primed seeds were lower compared with non-primed seeds or properly primed seeds.

• Applied Microscopy
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• v.25 no.4
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• pp.71-82
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• 1995

The ultrastructure and storage reserves of the Capsicum annuum seeds were studied in order to identify structure and to localize storage components in the endosperm using light microscopy, scanning and transmission electron microscopy. The seed coat was composed of one cell layer which contained a large number of lipid bodies, while most of the endosperm cells did not showed many lipid bodies. During seed maturation, the endosperm cells were continuously degenerated by the autophagy. Various types of plastids were also distinguished in the endosperm cells. They contained starch grains surrounded by electron-dense tiny particles, plastoglobuli, and vasicular bodies.