To induce the enhanced mutants of dinitroaniline herbicide pendimethalin degrading bacterium, Bacillus sp. MS202 was irradiated with gamma radiation at the dose of LD99 (3.35 kGy). Three enhanced mutants (MS202m7, MS202m14, MS202m18) were isolated fr

본 연구에서는 실내실험을 통하여 개량형 공압식 가동보를 대상으로 보의 기립각도를 고려한 유사의 퇴적과 델타의 발달 과정을 파악하였다. 가동보 상류에서 유입되는 유사는 배수의 영향으로 유속이 느려지면서 퇴적이 되고 델타가 형성되며 하류로 이동하였다. 각 실험조건에 대하여 시간에 따른 델타의 이동속도는 델타는 시간이 지나면서 현저하게 감소하고, 보에 접근하였다. 무차원 델타의 높이(hd/h)가 증가할수록 무차원 델타의 이동속도(SD/V0)는 감소하였다. 따라서 델타의 높이(hd)가 증가할수록 수심(h)은 감소하였다. 델타의 유효높이(hw)가 크기 때문에 델타의 체적 (VxD)은 증가하지만 배수(backwater)의 영향을 받아 델타의 이동속도(SD)와 퇴적량은 감소하였다. 수로 경사가 일정할 때, 보의 높이(W)가 클수록 델타체적(VxD)이 증가하고, 델타의 전면부 길이비(hd/△S)는 1에 가깝다. 같은 유량조건인 경우에 가동보의 기립 각도가 가장 클 때, 시간당 델타의 퇴적량(Qs)은 가장 작았다. 따라서 보의 높이(W)가 클수록 델타의 발달을 억제할 수 있는 효과가 크다.

본 연구에서는 실내실험을 통하여 개량형 공압식 가동보를 대상으로 수로경사 변화를 고려한 유사의 수리학적 발달 과정을 분석하였다. 분석결과 보에 의하여 형성된 델타는 시간이 증가함에 따라 하류로 이동하며, 델타높이(hd)는 증가하였다. 또한 보에 도달 할수록 흐름이 약해지면서 델타의 이동속도(SD)는 감소하였다. 무차원 델타 위치(xD/x)가 증가할수록 무차원 델타의 유효높이(hd/hw)와 무차원 저수지 용량(VxD/Vx)이 증가였다. 따라서 동일한 조건에서 수로경사(i)가 완만할수록 델타의 퇴적량(QS)이 감소하게 되며, 델타의 체적(VxD) 발달에 큰 영향을 미치는 것으로 나타났다. 통수 초기 델타의 전면경사가 완만하며, 델타가 하류로 이동할수록 델타의 전면경사는 증가하였다. 또한 수로경사(i)가 완만할수록 델타의 전면부 길이 비(hd/△S)는 1에 가까워지고, 무차원 델타의 높이(hd/h)와 무차원 델타의 이동속도(SD/V0)가 감소하였다. 델타의 높이(hd)가 증가할수록 수심(h)은 감소하였으며, 보에 접근하는 유속(V0)과 델타의 이동속도(SD)도 감소하였다.

장 건강에 유익한 프리바이오틱스 소재를 개발하기 위하여 배변을 촉진하는 효능을 지닌 붉은팥을 식품 발효에 이용되는 Bacillus subtilis KCCM 11965P로 발효하여 다음과 같은 결과를 얻었다. 붉은팥의 일반성분은 회분 3.35±0.04%, 조단백질 21.1±0.19%, 조지방 0.35±0.02% 함 유되었다. 붉은팥 원물 1%, 3%, 5%와 Bacillus subtilis KCCM 11965P 3% (v/v)를 접종하여 0, 24, 48, 72시간 배양 하였다. 배양액의 총균수를 측정한 결과 붉은팥 원물을 3% 첨가한 후 72시간 배양군에서 Bacillus subtilis KCCM 11965P 발효가 가장 적합하였다. 발효 시간에 증가함에 따라 총 폴리페놀 함량과 DPPH 라디칼 소거활성이 증가하였다. Protease 활성은 붉은팥 원물 5% 첨가한 후 72시간 배양한 군(2.69±0.003 unit/mL)에서 활성이 가장 높았다. 발효시간과 붉은팥 원물 첨가 농도가 증가함에 따라 α -amylase 활성도 증가하였으며, 붉은팥 원물 5% 첨가한 후 72시간 배양한 군에서 0시간 배양군(1.0±0.1 unit/mL) 보다 26.0±0.2 unit/mL로 증가하였다. Bacillus subtilis KCCM 11965P로 72시간 배양한 후 유리아미노산을 측정한 결과 leucine은 붉은팥 원물 5% 첨가한 0시간 배양군 5.22 mg/L 에서 67.59 mg/L로 증가하였으며, 비필수아미노산인 tyrosine은 5% 첨가 0시간 배양군 10.08 mg/L에서 259.35 mg/L로 증가하였다. 이와 같이 Bacillus subtilis KCCM 11965P로 붉은팥을 발효하면 항산화 활성, protease 효소활성, 및 α-amylase 효소 활성이 증가하였으며, 유리아미노 산과 유기산이 증가하였다. 붉은팥을 발효하는데 Bacillus subtilis KCCM 11965P가 적합할 것으로 판단되며, 붉은팥은 프로바이오틱스를 활성화시켜 장 건강을 증진시킬 수 있는 프리바이오틱스 소재로 개발할 수 있는 가능성을 시사 하였다.

Eleutherococcus senticosus (Siberian ginseng) is an important medicinal tree found in northeast Asia. In this study, we analyzed the genome-wide distribution of microsatellites in E. senticosus. By sequencing 711 clones from an SSR-enriched genomic DNA library, we obtained 12 polymorphic SSR markers, which also revealed successful amplicons in E. senticosus accessions. Using the developed SSR markers, we estimated genetic diversity and population structure among 131 E. senticosus accessions in Korea and China. The number of alleles ranged from 2 to 11, with an average of 7.4 alleles. The mean values of observed heterozygosity (HO) and expected heterozygosity (HE) were 0.59 and 0.56, respectively. The average polymorphism information content (PIC) was 0.51 in all 131 E. senticosus accessions. E. senticosus accessions in Korea and China showed a close genetic similarity. Significantly low pairwise genetic divergence was observed between the two regions, suggesting a relatively narrow level of genetic basis among E. senticosus accessions. Our results not only provide molecular tools for genetic studies in E. senticosus but are also helpful for conservation and E. senticosus breeding programs.

Acyl-acyl carrier protein (ACP) thioesterase (TE) catalyze the hydrolysis of the thioester bond that links the acyl chain to the sulfhydryl group of the phosphopantetheine prosthetic group of ACP. This reaction terminates acyl chain elongation of fatty acid biosynthesis, and in plant seeds it is the biochemical determinant of the fatty acid compositions of storage lipids. A full-length cDNA of an acyl-ACP thioesterase, named CvFatB, was isolated from oil plant Cuphea viscosissima accumulating up to 90% caprylate (8:0) and caprate (10:0) in its seed oil. This cDNA contains a 1,245-bp open reading frame that encodes a protein of 415 amino acids. The deduced sequence also contains two essential residues (H317 and C352) for TE catalytic activity and a putative chloroplast transit peptide at the N-terminal. Overexpression of the CvFatB cDNA in Arabidopsis resulted in increased levels of saturated fatty acid, especially palmitate, and reduced levels of unsaturated fatty acids. The findings suggest that CvFatB from oil plant C. viscosissima can function as a saturated acyl-ACP TE and can potentially be used to diversify the fatty acid biosynthesis pathway to produce novel fatty acids.

The influences of ethylene inhibitors (AgNO3 and silver thiosulfate) and cytokinins (BAP and TDZ) on shoot regeneration from cotyledon and hypocotyl explants of B. napus cv. Youngsan were investigated. The presence of 50 μM Silver thiosulfate (STS) in shoot regeneration medium formed shoots at 60-68% after 3-4 weeks of culture, which was enhanced by 2-fold compared to that of Silver nitrate (AgNO3). Moreover, cotyledon explants were more regenerative than hypocotyls; shoots from cotyledon explants began to occur 4-5 days earlier than that of hypocotyl explants. TDZ at a concentration of 8-10 μM was effective for shoot regeneration, compared with BAP. Consequently, the optimal shoot regeneration response was observed in medium supplemented with 50 μM STS + 8 μM TDZ. In transmission electron microscopy (TEM) analysis, higher density of silver nanoparticles was shown to be accumulated widely inside the cell wall and plasmodesmata of regenerating leaf cultured in medium supplemented with AgNO3. By contrast, in the cell cultured in medium with STS, fine-grained deposits were partly observed in the surroundings of the cell wall.

Recent release of whole genome draft sequences in legume species have led comparative genome studies among legume plants including Glycine max, G. soja, Cajanus cajan and Medicago truncatula. The majority of comparative genomic researches have been conducted based on synteny of coding sequences and coding sequence variations may be one of major forces for speciation and evolution. However, non-coding sequences have been also reported to be important phenotypic regulators. Especially, since short sequence motifs in the promoter regions are highly conserved, they are suggested to be another resources of interests in comparative studies. In this study, we predicted the conserved short sequence motifs by BLASTN algorithm using dicot promoter database from Softberry (http://www.softberry.com). A total of 37,396 conserved short sequence motifs were identified onto 2 kb upstreams of 46,367 high confident gene model of G. max (cv. Williams 82). Meanwhile, whole genome of 7 soybean landraces (G. max) and 7 wild soybean genotypes (G. soja) were sequenced at low depth of less than ten using Illumina Hiseq 2000. Among these genotypes, nucleotide variations were identified in predicted conserved regulatory motifs by mapping of short reads to the reference genome sequence using the Samtools program (http://samtools.sourceforge.net/). Fifteen and two genes, which have SNPs in regulatory motifs and no SNP in coding sequence, were identified by comparisons of inter-species and intra-species, respectively. qRT-PCR experiments are in progress for investigating differences of these 17 genes expressions at transcriptional level.

As soybean (Glycine max) is known for its high nutritional value of oil and protein, soybean has been domesticated and cultivated by one specific character trait based on human selection. Importantly, tracing back in time where G. max and G. soja, the undomesticated ancestor of G. max have diverged plays an important role in studying of genetic diversity and in investigating the common ancestor of soybean. In this study, we sequenced 6 G. max and 6 G. soja using Illumina’s Hiseq 2000 with a low coverage sequencing technology to estimate the divergence of times between genotypes and populations. A total of the 12 genotypes were sequenced at the average depth of 6.5 and resulted 892.5 Mb and 903.3 MB consensus sequences with the coverage of 91.54% and 92.65% for G. max and G. soja, respectively. The whole genome SNP analysis showed that G. max had lower frequency levels of polymorphism (~0.1%) than G. soja (~0.25%). And, a high number of SNPs located in introns were found among 6 G. soja genotypes as SNPs were approximately twice than those found in 6 G max. The number of SNPs in G. max intronic regions was 53,134, whereas a total of 133,329 SNPs were discovered in G. soja introns. Almost an equal number of SNPs were discovered in 5’ UTR and exon regions; however, different numbers of SNP in CDS and 3′ UTR were identified. By the rate of nonsynonymous change, divergence of time between G. soja and G. max would be investigated.

Phytic acid, myo-inositol (1, 2, 3, 4, 5, 6)-hexakisphosphate, is a material that plants store phosphorus in seeds. Phytic acid is classified as an antinutrient because of indigestibility. Non-ruminant animals, such as human and swine, excrete unavailable phytic acid. The unavailable phytic acid run off to ground water, river, sea, causing eutrophication as a factor. Accordingly, low-phytic acid crops draw the attention due to both nutritional and environmental reasons. Using more than 900 Glycine accessions including G. max, G. soja and G. gracillis, colormetric method was applied for detecting low-phytic acid mutant. Two hundred fifty accessions were screened by the colormetric method so far, but no mutant was identified. Screening of mutants with the rest 710 accessions is in progress. MIPS1 (D-myo-inositol 3-phosphate synthase) is considered as gene related to phytic acid content in soybean. Also, lpa1 (Zea mays low phytic acid 1) known as controlling phytic acid content in maize was recently reported that homologs of lpa1 were responsible for phytic acid content in soybean and located on linkage groups L and N (Chromosomes 19 and 3). After primers were designed from these three candidate genes for phytic acid content, identification of genes responsible for low phytic acid and investigation of genetic variation among 960 accessions will be performed as further study.