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The field study was undertaken to examine the potential for adverse effects of transgenic soybean expressing bioactive human epidermal growth factor (with tolerance to the herbicide glufosinate, PPT) on the abundance and diversity of plant‐dwelling arthropods by comparing with those of a non‐GM parental cultivar, Gwangan soybean. Field surveys of soybean fields were carried out over two consecutive years, 2016 and 2017 at Ochang and Jeonju, Korea. The number of captured individuals associated with either of EGF and Gwangan soybean plants increased in 2017 compared with 2016 in both Ochang and Jeonju. During the survey period, the diversity and richness of the occurred insects and arachnids increased, dominance decreased, and the evenness of the insects remained static. The insects of Hymenoptera Order occurred most often comprised 25.4% of total captured insect pests. On the contrary, natural enemy from Hymenoptera Order and other insects from Diptera Order occurred more frequently (29.9% and 19.0%, respectively) in both the survey regions during the study periods. The score from PROXSCAL multidimensional scaling using combined data showed that the occurrence of insects and arachnids were separated due to their cultivation regions and years, irrespective of soybean cultivars. Consequently, the results indicated that there happened no notable change in the composition of arthropod communities in soybean agroecosystem due to GM event in soybean expressing EGF.

Ginseng is a traditional medicine with health benefits for humans. Protopanaxadiol (PPD) is an important bioactive compound found in ginseng. Transgenic rice containing PPD has been generated previously. In the present study, extracts of this transgenic rice were evaluated to assess their antiadipogenic and anti-inflammatory activities. During adipogenesis, cells were treated with transgenic rice seed extracts. The results revealed that the concentrations of the rice seed extracts tested in this study did not affect cell viability at 3 days post-treatment. However, the rice seed extracts significantly reduced the accumulation of lipids in cells and suppressed the activation of CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ), which in turn inhibited the expression of adipogenesis-related mRNAs, such as adiponectin, PPARγ, C/EBPα, sterol regulatory element-binding protein 1, glucose transport member 4, and fatty acid synthase. In adipocytes, the extracts significantly reduced the mRNA expression of inflammation-related factors following LPS treatment. The activation of NF-κB p65 and ERK 1/2 was inhibited in extract-treated adipocytes. Moreover, treatment with extract #8 markedly reduced the cell population of the G2/M phase. Collectively, these results indicate that transgenic rice containing PPD may act as an obesity-reducing and/or -preventing agent.

Event DS rice producing protopanaxadiol (PPD) has been previously developed by inserting Panax ginseng dammarenediol-II synthase gene (PgDDS) and PPD synthase gene (CYP716A47). We performed a gas chromatography–mass spectrometry (GC–MS)-based metabolomics of the DS rice to identify metabolic alterations as the effects of genetic engineering by measuring the contents of 65 metabolites in seeds and 63 metabolites in leaves. Multivariate analysis and one-way analysis of variance between DS and non-genetically modified (GM) rice showed that DS rice accumulated fewer tocotrienols, tocopherols, and phytosterols than non-GM rice. These results may be due to competition for the same precursors because PPDs in DS rice are synthesized from the same precursors as those of phytosterols. In addition, multivariate analysis of metabolic data from rice leaves revealed that composition differed by growth stage rather than genetic modifications. Our results demonstrate the potential of metabolomics for identifying metabolic alterations in response to genetic modifications.

Although susceptibility to seed shattering causes severe yield loss during cereal crop harvest, it is an adaptive trait for seed dispersal in wild plants. We previously identified a recessive shattering locus, sh-h, from the rice shattering mutant line Hsh that carries an enhanced abscission layer. Here, we further mapped sh-h to a 34-kb region on chromosome 7 by analyzing 240 F2 plants and five F3 lines from the cross between Hsh and Blue&Gundil. Hsh had a point mutation at the 3′ splice site of the seventh intron within LOC_Os07g10690, causing a 15-bp deletion of its mRNA as a result of altered splicing. Two transferred DNA (T-DNA) insertion mutants and one point mutant exhibited the enhanced shattering phenotype, confirming that LOC_Os07g10690 is indeed the sh-h gene. RNA interference (RNAi) transgenic lines with suppressed expression of this gene exhibited greater shattering. This gene, which encodes a protein containing a conserved carboxy-terminal domain (CTD) phosphatase domain, was named Oryza sativa CTD phosphatase-like 1 ( OsCPL1). Subcellular localization and biochemical analysis revealed that the OsCPL1 protein is a nuclear phosphatase, a common characteristic of metazoan CTD phosphatases involved in cell differentiation. These results demonstrate that OsCPL1 represses differentiation of the abscission layer during panicle development. [ABSTRACT FROM AUTHOR]

A gene detection strategy using two-component Ac/Ds construct, with the mobile Ds transposon, has been developed to better understand gene functions in crops. Currently, 115,000 Ds insertion lines have been generated through the Ac/Ds gene trap system in Korea using japonica rice Dongjin as donor. Four hundred and thirty-seven mutants from 12,162 Ds-tagged lines were catalogued, including physiological and agronomic traits. Different traits were identified with distinct characteristics in terms of tillers, panicles, leaves, flowers, seed, chlorophyll content, and height. Culm and panicle length, number of panicles, and days to flowering of the Dongjin Ds population revealed high standard deviations compared with the donor cultivar. An evaluation of the Ds distribution on the chromosome revealed that 74.5% of the Ds were reinserted into gene-rich regions, making this Ac/Ds-mediated gene trap system useful in helping to gain an understanding of the function of genes and thus improve the gene-tagging system in rice. [ABSTRACT FROM AUTHOR]

OSH6 ( Oryza sativa Homeobox6) is an ortholog of lg3 (Liguleless3) in maize. We generated a novel allele, termed OSH6-Ds, by inserting a defective Ds element into the third exon of OSH6, which resulted in a truncated OSH6 mRNA. The truncated mRNA was expressed ectopically in leaf tissues and encoded the N-terminal region of OSH6, which includes the KNOX1 and partial KNOX2 subdomains. This recessive mutant showed outgrowth of bracts or produced leaves at the basal node of the panicle. These phenotypes distinguished it from the OSH6 transgene whose ectopic expression led to a “blade to sheath transformation” phenotype at the midrib region of leaves, similar to that seen in dominant Lg3 mutants. Expression of a similar truncated OSH6 cDNA from the 35S promoter ( 35S:: ΔOSH6) confirmed that the ectopic expression of this product was responsible for the aberrant bract development. These data suggest that OSH6-Ds interferes with a developmental mechanism involved in bract differentiation, especially at the basal nodes of panicles. [ABSTRACT FROM AUTHOR]

Rapid, large-scale generation of a Ds transposant population was achieved using a regeneration procedure involving tissue culture of seed-derived calli carrying Ac and inactive Ds elements. In the F2 progeny from genetic crosses between the same Ds and Ac starter lines, most of the crosses produced an independent germinal transposition frequency of 10–20%. Also, many Ds elements underwent immobilization even though Ac was expressed. By comparison, in a callus-derived regenerated population, over 70% of plants carried independent Ds insertions, indicating transposition early in callus formation. In the remaining population, the majority of plants carried only Ac. Most of the new Ds insertions were stably transmitted to a subsequent generation. An exceptionally high proportion of independent transposants in the regenerated population means that selection markers for transposed Ds and continual monitoring of Ac/ Ds activities may not necessarily be required. By analyzing 1297 Ds-flanking DNA sequences, a genetic map of 1072 Ds insertion sites was developed. The map showed that Ds elements were transposed onto all of the rice chromosomes, with preference not only near donor sites (36%) but also on certain physically unlinked arms. Populations from both genetic crossing and tissue culture showed the same distribution patterns of Ds insertion sites. The information of these mapped Ds insertion sites was deposited in GenBank. Among them, 55% of Ds elements were on predicted open-reading frame (ORF) regions. Thus, we propose an optimal strategy for the rapid generation of a large population of Ds transposants in rice. [ABSTRACT FROM AUTHOR]

To construct a molecular genetic map using PCR-based DNA markers with the recombinant inbred population derived from Milyang23/Gihobyeo cross, we analyzed the STS, InDel, RTM, and SSR markers which are mainly able to be analyzed on agarose gel. A genetic map comprised of 224 markers including 37 InDel, 88 STS, 8 RTM and 91 SSR markers was constructed. This map contained 1,425 cM with an average interval size of 6.7 cM. The physical map of these markers was also constructed by analyzing the physical location of each maker using its primer sequences and e-PCR program, and the average physical distance per centimorgan was 250 kbp. Among the mapped markers, 51 (22.8%) showed segregation distortion at 5% significance level. They are mainly located in the middle part of chromosome 3, almost whole chromosome 6, the upper end of chromosome 7, the lower end of chromosome 8, and the upper end of chromosome 12. These molecular genetic and physical maps would provide information on the available markers for mapping genes of useful traits with population derived from the crosses between Japonica varieties and Tongil type or Indica varieties. [ABSTRACT FROM AUTHOR]