• Proceedings of the Botanical Society of Korea Conference
• /
• 1996.07a
• /
• pp.61-74
• /
• 1996

Human and monogastric animals can not synthesize 10 out of the 20 amino asids and therefor need to obtain these from their diet. The plant seed is a major source of dietary protein. It is particular important in their study to increase nutritional quality of the seed storage proteins. The low contents of lysine, asparagine and threonenein various cereal seeds and of cystein and methionine. In legume seeds is due to the low proportions of these amino acids in the major storage proteins, we have tried to apply the three strategies; (1) mutagenesis and selection of specific amino acid analogue resistance, (2) cloning and expression study of lysine biosynthesis related gene, (3) transfomation of lysine rich soybean glycinin gene. The 5-methyltryptophan (5MT) resistant cell lines, SAR1, SAR2 and SAR3 were selected from anther derived callus of rice (Oryza sativa L. "Sasanishiki"). Among these selected cell lines, two (SAR1 and SAR3) were able to grow stably at 200 mg/L of 5MT. Analysis of the freed amino acids in callus shows that 5MT resistant cells (SAR3) accumulated free tryptophan at least up to 50 times higher than those that of the higher than of SAS. These results indicated that the 5MT resistant cell lines are useful in studies of amino acid biosynthesis. Tr75, a rice (Oryza sativa L., var. Sasanishiki) mutant resistant to 5MT was segregated from the progenies of its initial mutant line, TR1. The 5MT resistant of TR75 was inherited in the M8 generations as a single dominant nuclear gene. The content of free amino acids in the TR75 homozygous seeds increased approximately 1.5 to 2.0 fold compared to wild-type seeds. Especially, the contents of tryptophan, phenylalanine and aspartic acid were 5.0, 5.3 and 2.7 times higher than those of wild-type seeds, respectively. The content of lysine is significantly low in rice. The lysine is synthesized by a complex pathway that is predominantly regulated by feedback inhibition of several enzymes including asparginase, aspatate kinase, dihydrodipicolinat synthase, etc. For understanding the regulation mechanism of lysine synthesis in rice, we try to clone the lysine biosynthetic metabolism related gene, DHPS and asparaginase, from rice. We have isolated a rice DHPS genomic clone which contains an ORF of 1044 nucleotides (347 amino acids, Mr. 38, 381 daltons), an intron of 587 nucleotides and 5'and 3'-flanking regions by screening of rice genomic DNA library. Deduced amino acid sequence of mature peptide domain of GDHPS clone is highly conserved in monocot and dicot plants whereas that of transit peptide domain is extremely different depending on plant specie. Southern blot analysis indicated that GDHPS is located two copy gene in rice genome. The transcripts of a rice GDHPS were expressed in leaves and roots but not detected in callus tissues. The transcription level of GDHPS is much higher in leaves indicating enormous chloroplast development than roots. Genomic DNA clones for asparaginase genes were screened from the rice genomic library by using plaque hybridization technique. Twelve different genomic clones were isolated from first and second screening, and 8 of 12 clones were analyzed by restriction patterns and identified by Southern Blotting, Restriction enzyme digestion patterns and Southern blot analysis of 8 clones show the different pattern for asparaginase gene. Genomic Southern blot analysis from rice were done. It is estimated that rice has at least 2-3 copy of asparaginase gene. One of 8 positive clones was subcloned into the pBluescript SK(+) vector, and was constructed the physical map. For transformation of lysine rich storage protein into tobacco, soybean glycinin genes are transformed into tobacco. To examine whether glycinin could be stably accumulated in endosperm tissue, the glycinin cDNA was transcriptionally fused to an endosperm-specific promotor of the rice storage protein glutelin gene and then introduced into tobacco genomic via Agrobacterium-mediated transformation. Consequently the glycinin gene was expressed in a seed-and developmentally-specific manner in transgenic tobacco seeds. Glycinin were targeted to vacuole-derived protein bodies in the endosperm tissue and highly accumulated in the matrix region of many transgenic plant (1-4% of total seed proteins). Synthesized glycinin was processed into mature form, and assembled into a hexamer in a similar manner as the glycinin in soybean seed. Modified glycinin, in which 4 contiguous methionine residues were inserted at the variable regions corresponding to the C - teminal regions of the acidic and basic polypeptides, were also found to be accumulated similarly as in the normal glycinin. There was no apparent difference in the expression level, processing and targeting to protein bodies, or accumulation level between normal and modified glycinin. glycinin.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.4
• /
• pp.448-457
• /
• 2015

Developing rice lines with various amylose contents is necessary to diverse usages of rice in terms of raw materials for processed food production, and thereby to promote rice consumption in Korea. A rice mutant line, 'Namil(SA)-dull1' was established through sodium azide mutagenesis on 'Namil', a non-glutinous Korean Japonica rice cultivar. Namil(SA)-dull1' had dull endosperm characteristics and the evaluated amylose content was 12.2%. A total of 94 F2 progenies from a cross between 'Namil(SA)-dull1' and 'Milyang23', a non-glutinous Tongil-type rice cultivar, was used for genetic studies on the endosperm amylose content. Association analyses, between marker genotypes of 53 SSR anchor markers and evaluated amylose contents of each 94 F2:3 seeds, initially localized rice chromosome 6 as the harboring place for the modified allele(s) directing low amylose content of 'Namil(SA)-dull1'. By increasing SSR marker density on the putative chromosomal region followed by association analyses, the target region was narrowed down 0.94 Mbp segment, expanding from 28.95 Mbp to 29.89 Mbp, on rice chromosome 6 pseudomolecule. Among the SSR loci, RM7555 explained 84.2% of total variation of amylose contents in the $F_2$ population. Further physical mapping on the target region directing low amylose content of 'Namil(SA)-dull1' would increase the breeding efficiency in developing promising rice cultivars with various endosperm characteristics.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.3
• /
• pp.205-211
• /
• 2005

This study was carried out to construct cold-tolerance characteristics. The RILs were developed from progenies of a cross between cold-susceptible Tongil-type rice variety, Milyang 23 and cold-tolerant Japonica rice variety, Stejaree 45 by single seed descent methods. The 175 RILs $(F_8)$ were evaluated for cold tolerance traits by field screening under cold-water irrigation. Frequency distribution of RILs in leaf discoloration, heading delay, culm length reduction and number of spikelets reduction displayed nearly normal distributions with transgressive segregations to either side of parents, while the spikelet fertility reduction and panicle exsertion at low-temperature showed the more or less skewed continuous distribution toward the susceptible parent. Higher heritabilities over $60\%$ were observed in leaf discoloration, spikelet fertility reduction, panicle exsertion, while relatively lower heritabilities less than $40\%$ were observed in culm length reduction, number of spikelets reduction and grain yield reduction. Some cold-tolerance RILs were selected effectively by cold water irrigation, which are expected to be good materials in breeding program for cold tolerance.

• The Korean Journal of Mycology
• /
• v.22 no.1
• /
• pp.107-116
• /
• 1994

Interorder somatic hybrids were obtained by protoplast fusion between Pleurotus ostreatus in the order Agaricales and Elfvingia applanata in the order Aphyllophorales. The fusants were classified into stable heterokaryons and spontaneously segregated heterokaryons. Hyphae of all fusion products except two strains did not form clamp connections. Out of them, two clamped and three clampless fusants produced mature fruiting bodies by light-dark cycle on sawdust rice bran medium. All of these basidiocarps had clamp connections. Three fusants were analysed with the distribution of progenies and segregation of genetic characters by random spore analyses. The genetic markers were shown to segregate and recombine in the first generation of monospores isolated from basidiocarps. Phenotypes of a large number of auxotrophic progenies were not detected in the two clamped fusants. The aberration ratio of segregants indicated the gene interaction resulting from different genome structure between distantly related species. The polymerase chain reaction (PCR) was adopted for the detection of somatic hybrids nuclear DNA. Four fusants showed a positive results in three kinds of primers. The prominent reaction products are represented by new bands in primer # 87 and # 125. Out of four fusants, two somatic hybrids had non-parental mtDNA patterns when digested with EcoR1 and HindIII. Comparison of somatic hybrids, tissue culture isolates(TC) and multispore germination isolates(MS) were made using esterase isozyme analysis. It is apparent that somatic hybrids had a minor banding patterns which are quite different from those of parents.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.30 no.4
• /
• pp.460-470
• /
• 1985

Experiments were carried out to evaluate the standard gravity in determining potential kernel size and to determine the effective sampling way by analyzing intra - and inter - plant variations for some source and sink characters using eleven semi-dwarf indica and three japonica cultivars including four semi-dwarf indica nearisogenic lines. Also, additional experiments were conducted to understand yearly variation and variety x year interaction effects for ten characters related to source and sink and to characterize the varietal difference of pre- and post-heading self-competition employing three parental varieties and their F$\sub$5/ progenies in 1982 and 1983. It is desirable to determine the potential kernel size by average kernel wight of rice grains showing above 1.15 specific gravity. There was significant difference in leaf area per tiller, spikelets and sink capacity per panicle among vigorous, intermediate and inferior tillers classified by differentiated order and vigorousness. Although it was difficult to find out any significant difference in grain-fill ratio, ratio of perfectly ripened grain, potential kernel size and sink/source ratio between vigorous and intermediate tillers, there was big difference between them and inferior one. The coefficients of variation within each tiller-group for some characters related to source and sink were larger with the order of vigorous tillers < intermediate one '||'&'||'lt; inferior one, and the average heritability of all characters, evaluated by the ratio of varietal variance (equation omitted) to total variance (equation omitted), were higher with the order of inferior tillers '||'&'||'lt; intemediate one '||'&'||'lt; superior one. Therefore, it is desirable to sample the vigorous tillers to represent the varietal difference of these traits. '82-'83 year variations of three parental cultivars were significant for all traits except for leaf area/tiller, panicles/hill, leaf area index and rough rice yield. The characters showing highly significant variance of variety x year interaction were growth duration from transplanting to heading, leaf area/tiller, sink/source ratio, sink capacity/panicle and grain yield. Generalized yearly response of three parental varieties (Suweon 264, Raegyeong, IR1317-70-l) and their F$\sub$5/ progenies on the 1st and 2nd principal components extracted from ten source and sink characters generally exhibited reduction in both source and sink. However, there were diverse variety x year interactions such as progenies showing similar reaction with their parents and intermediate or recombinational yearly response with little or considerable yearly movement on the four-dimensional planes of the two upper principal components between 1982 and 1983. Sink characters revealing highly significant border effect were grain-fill ratio, spikelets and sink capacity per panicle. Among them the latter two especially showed significant variety x border effect interaction. Self-competition characterized by relative weakness of inside plant's sink characters compared to the border one was more severe during the reproductive stage before heading than maturing stage. Though the larger sink capacity per panicle generally disclosed the severer self-competition, some lines (like Suweon 264) revealed severe self-competition with small sink capacity while a few others showed tender self-competition in spite of big sink capacity per panicle.

• Journal of Plant Biotechnology
• /
• v.36 no.1
• /
• pp.87-95
• /
• 2009

The recombinant DNAs, pGBF, pGTF, and pZ4F, using soybean ferritin gene have constructed with the promoters derived from seed proteins, glutelin, globulin, and zein. The recombinant ferritin genes were transformed into rice plant by Agrobacterium-mediated transformation. Iron contents and agronomic traits have been evaluated in the transgenic progenies. The embryogenic calli survived from second selection medium were regenerated at the rates of 19.2% with pGBF, 15.0% with pGTF, and 18.4% with pZ4F in Donganbyeo and 6.7% with pGBF, 11.7% with pGTF, and 3.4% with pZ4F in Hwashinbyeo. The introduction of ferritin gene in putative transgenic rice plants was confirmed by PCR and Southern blot analysis and also the expression of ferritin gene was identified by Northern blot and Western blot analysis. The iron accumulation in transgenic rice grains of the transgenic rice plant, T1-2, with zein promoter and ferritin gene contained 171.4 ppm showing 6.4 times higher than 26.7 ppm of Hwashinbyeo seed as wild type rice, but the transgenic plants with globulin and glutelin showed a bit higher iron contents with a range from 2.1 to 3.0 times compare to wild type grain. The growth responses of transgenic plants showed the large variances in plant height and number of tillers. However, there were some transgenic plants having similar phenotype to wild type plants. In the T1 generation of transgenic plants, plant height, culm length, panicle length, and number of tillers were similar to those of wild type plants, but ripened grain ratio ranged from 53.3% to 82.2% with relatively high variation. The transgenic rice plants would be useful for developing rice varieties with high iron content in rice grains.

• Journal of Life Science
• /
• v.22 no.12
• /
• pp.1628-1636
• /
• 2012

This study examined the antioxidant activity of the dark purple rice seeds from the rice line, MGI079, derived from insertional mutagenesis. The contents of polyphenolic compounds were 1.3 and 1.9-fold higher in the MGI079-2-1 and MGI079-2-6 rice lines than in the donor cultivar MGI079. Flavonoid contents were 6.4-fold higher in the MGI079-2-1 line. The MGI079-2-1 line showed a 24.4-fold higher activity in DPPH free radical scavenging compared to the MGI079 line. The anthocyanin content of the MGI079-2-6 line was more than 106.4-fold higher than the MGI079 line and 1.4-fold higher than the Heugnam line. Anthocyanin content in colored rice grains was negatively correlated with Hunter's L, a, and b values, with the correlation coefficients of $-5.64^{**}$, $5.21^{**}$ and -1.15, respectively. The grain length/width of a mutant of MGI079 segregated to a medium and bold type compared to the medium type of MGI079. However, the 1,000 grain weight was decreased to 13.6~19.6 g compared to 19.8 g for MGI079. Amylose content of the endosperm was 5.6~23.8% higher than in the MGI079 line. The grain of mutants of MGI079 was distinguished by its starch characteristics. The higher antioxidant activity of the MGI079-2-1 and MGI079-2-6 lines indicated functional characteristics associated with high-value resources, so future breeding should focus on the development of pigments in colored rice in new varieties.

• Korean Journal of Breeding Science
• /
• v.43 no.5
• /
• pp.375-382
• /
• 2011

A chemical, MNU-induced hulless barley mutant line designated as 'Mutant 98 (M98)' was developed from a Korean hulless waxy barley cultivar, 'Chalssalbori'. The objective of the study was to determine the genetic basis of 'M98' and the possibility of using 'M98' as breeding parent to improve lysine level. Compared to 'Chalssalbori', 'M98' had large embryo and higher lysine content in both the embryo and endosperm. Significantly different lysine content in 'M98' and the other high-lysine barley mutant stocks was observed for two years. However, the genotype by year interaction was not significant. 'M98' was higher than the other high-lysine barley mutant stocks in the percentage of lysine of total amino acid composition (0.75%). The trait of shrunken endosperm of 'M98', which was typical in the high-lysine mutants, was inherited by a single recessive gene. Based on seed morphology and lysine content of $F_1$ seeds, 'M98' had a genetically different gene from the other high-lysine mutants for shrunken endosperm. Segregation of $F_2$ for plump/shrunken endosperm did not fit the expected ratio of Mendelian inheritance except for only one cross combination (GSHO1784 (lys1)/M98). The amino acid analysis of $F_5$ and $F_6$ progenies from the cross between 'M98' and 'Chalssalbori' revealed that the attempt to increase the range of lysine content of plump lines did not go beyond the limit of the average high-lysine barley germplasm.

• Journal of Life Science
• /
• v.28 no.4
• /
• pp.398-407
• /
• 2018

The Purple pericarp (Prp) trait is a trait often bred for in black rice. Generally, the Prp trait is displayed in the color variations of seeds following the 9:3:4 purple, brown, and white ratio, respectively. The Prp trait is a recessive epistasis of two gene interactions; however, it is caused by the two complementation genes Pb and Pp. Here we present a study of the genetic characteristics of the Prp trait using an $F_1$ hybrid with a Pbpb Pppp genotype. This hybrid generated four seed colors with the following numbers: 3 dark purple, 6 medium purple, 3 brown, and 4 white (or 9 purple, 3 brown, and 4 white). However, further biochemical analysis of the all progenies divided them into two groups. One group had the Pb_ Pp_ allelic constitutions and contained cyanidin 3-O-glucoside (C3G) in both the dark purple or medium purple seeds. The other group, however, was absent of C3G in both the brown and white seeds, resulting in a ratio of 9:7, respectively. This segregation revealed the extended Mendelian 9:7 ratios of the complementary gene interactions with a good fitness in ${\chi}^2$ analysis. Further analysis revealed that brown seeds with the Pb_ pppp genotype corresponded with a null C3G, indicating that the Brown pericarp trait in rice is caused by a dominant allele of the Pb gene. Therefore, we conclude that the production of C3G is a main phenotype of the black and purple colored rice in the Prp trait, and it is governed by the complementary gene interactions between Pb and Pp genes.

• Korean journal of applied entomology
• /
• v.15 no.4 s.29
• /
• pp.163-168
• /
• 1976

The present study was conducted to determine the number of genes controlling resistance of variety Tongil to three prevalent blast strains and any relationships among the genes in the inheritance of resistance of the variety to blast. Tongil was crossed with five local varieties and the progenies were tested with blast isolates E-7 and 100-14 by injection inoculation method. Results indicated that a tingle dominant gene conditioned resistance of variety Tongil and resistance to the isolate E-7 was controlled by a gene different from that controlling resistance to the isolate 100-14. In previous study it was identified that the gene controlling resistance to the isolate E-7 was different from the gene for resistance to isolate T-1. Therefore based on the foregoing results it may be inferred that the variety Tongil has at least three or more resistant genes to blast.