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Ishimaru T.,International Rice Research Institute | Ishimaru T.,Japan International Research Center for Agricultural science | Hirabayashi H.,Japan National Agriculture and Food Research Organization | Sasaki K.,University of Tokyo | And 3 more authors.
Plant Production Science | Year: 2016

Global warming is predicted to aggravate the risk of unstable crop production. It is of great concern that damage to rice spikelet sterility and grain quality will increase, resulting in yield and economic losses. To secure the global food supply and farmers’ income, the development of rice cultivars with heat resilience is a pressing concern. Regarding spikelet sterility, rice cultivars with heat tolerance at different growth stages have been identified in recent years. The early-morning flowering (EMF) trait is effective in heat escape because it shifts the time of day of flowering to earlier in the morning when it is cooler. Although varietal differences are very small, there are some genetic resources for EMF in wild rice accessions. Regarding heat-induced grain chalkiness, heat-tolerant Japonica-type cultivars for mitigating white-back type of chalky grains (WBCG) were found. Quantitative trait loci for heat tolerance at flowering, EMF, and for WBCG in grain quality have been mapped on the rice chromosomes. Further genetic efforts have been successfully connected to the development of near-isogenic lines for each trait with tagged molecular markers. These breeding materials are quite unique and useful in facilitating marker-assisted breeding toward the development of heat-resilient rice in terms of spikelet sterility and grain quality. © 2016 The Author(s).

Teixeira da Silva J.A.,Kagawa University | Shinoyama H.,Fukui Agricultural Experiment Station | Aida R.,Japan National Agriculture and Food Research Organization | Matsushita Y.,Japan National Agriculture and Food Research Organization | And 2 more authors.
Critical Reviews in Plant Sciences | Year: 2013

Chrysanthemum is globally the second most important ornamental in terms of socioeconomic importance. Even though the vast range of flower colors, shapes and forms were initially created using conventional and mutation breeding, transgenic strategies are now more frequently used with Agrobacterium-mediated transformation being the most popular form of introducing foreign genes into chrysanthemums. Even so, transformation efficiency remains dependent on cultivar and regeneration procedure. Transgenic molecular breeding has seen the introduction of important traits such as novel flower color and form and plant architecture, prolonged cut-flower vase-life, resistance to biotic stresses such as viruses/viroids, pathogens and insects. However, chimerism and transgene silencing continue to be limiting factors. Transgenic strategies, despite opening up new avenues for creating new cultivars with improved agronomic and horticultural traits, may be limited due to the risk of transgenic pollen escaping into the wild. © 2013 Copyright Taylor and Francis Group, LLC.

Skaptsov M.,Altai State University | Kutsev M.,Altai State University | Filipenko M.,Institute of Chemical Biology and Fundamental Medicine | Khrapov E.,Institute of Chemical Biology and Fundamental Medicine | Shinoyama H.,Fukui Agricultural Experiment Station
Key Engineering Materials | Year: 2016

Detergents represent a unique class of chemical compounds. They can alter surface and interphase bonds, and form micellar systems. These detergent properties allow to alter wettability of surfaces, stabilize or destabilize dispersed systems, and modify the properties of liquid phases. Therefore, the use of detergents is virtually unlimited in chemical synthesis and processing, medicine, biological systems and agricultural biology. The article includes the studies of the feasibility of application of 1,1,1,3,5,5,5-heptamethyltrisiloxane modified by polyalkylene oxide in combination with allyloxypolyethyleneglycol in the ratio of 10:1 as a detergent for agrobacterialmediated transformation. Tween 20 detergent was used as a means of control in the concentration of 5%. As a result of histochemical analysis of transformed tissues, a significant difference was determined in expression of beta-glucuronidase reporter gene. The study of gene expression by calculating the relative content of mRNA showed that the initial number of mRNA copies of genetic makers transfected by co-culturing in a liquid medium with addition of Tween 20 is on the average 32% lower than when using modified heptamethyltrisiloxane. © Copyright 2016 Trans Tech Publications Ltd, Switzerland.

Matsushima R.,Okayama University | Maekawa M.,Okayama University | Kusano M.,University of Tsukuba | Kusano M.,RIKEN | And 6 more authors.
Plant Physiology | Year: 2016

Starch is a biologically and commercially important polymer of glucose. Starch is organized into starch grains (SGs) inside amyloplasts. The SG size differs depending on the plant species and is one of the most important factors for industrial applications of starch. There is limited information on genetic factors regulating SG sizes. In this study, we report the rice (Oryza sativa) mutant substandard starch grain6 (ssg6), which develops enlarged SGs in endosperm. Enlarged SGs are observed starting at 3 d after flowering. During endosperm development, a number of smaller SGs appear and coexist with enlarged SGs in the same cells. The ssg6 mutation also affects SG morphologies in pollen. The SSG6 gene was identified by map-based cloning and microarray analysis. SSG6 encodes a protein homologous to aminotransferase. SSG6 differs from other rice homologs in that it has a transmembrane domain. SSG6-green fluorescent protein is localized in the amyloplast membrane surrounding SGs in rice endosperm, pollen, and pericarp. The results of this study suggest that SSG6 is a novel protein that controls SG size. SSG6 will be a useful molecular tool for future starch breeding and applications. © 2016 American Society of Plant Biologists. All Rights Reserved.

Shinoyama H.,Fukui Agricultural Experiment Station | Mitsuhara I.,Japan National Institute of Agrobiological Science | Ichikawa H.,Japan National Institute of Agrobiological Science | Kato K.,Nara Institute of Science and Technology | Mochizuki A.,Japan National Institute for Agro - Environmental Sciences
Acta Horticulturae | Year: 2015

The chrysanthemum (Chrysanthemum morifolium Ramat.) is a very important ornamental flower worldwide. Damage due to both harmful insects and pathogenic microbes results in a loß of quality and leads to high control costs. To reduce the likelihood of such damage, we have developed genetically modified chrysanthemums by introducing a modified cry1Ab gene of Bacillus thuringiensis var. kurstaki HD-1 (mcbt) and a modified sarcotoxin IA gene of Sarcophaga peregrina (msar) with or without the 5'-untranslated region of the alcohol dehydrogenase gene of Arabidopsis thaliana (AtADH-5'UTR, as ADH). The leaf discs were transformed using a disarmed strain of Agrobacterium tumefaciens, EHA105, carrying the binary vectors pBIK201BPS or pBIK201ABPS, which contain the mcbt and msar genes. The mcbt and msar genes were detected in all regenerated plantlets by Southern blot analysis, with a transformation frequency of 6.8%. Northern blot analysis revealed that the amount of the mcbt transcription was influenced by the transgene copy number in the genetically modified (GM) chrysanthemum. However, that of the msar transcript was influenced by the presence of the HSP terminator, regardleß of the gene copy number. The GM chrysanthemums accumulated more than 1.31 ?g of Cry1Ab per mg of total soluble protein and showed a strong resistance against 4 species of lepidopteran larvae (Helicoverpa armigera and others). All larvae died during the first instar stage. A strong resistance against white rust by Puccinia horiana was observed especially in the ADH::msar-transgenic chrysanthemum in which the expreßion level of sarcotoxin IA peptide was more than 19.5 ?g per g fresh weight of leaves. These GM chrysanthemums will be useful in reducing control costs for lepidopteran insects and white rust disease.

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