- Email: [email protected]
Modified biosynthesis of polyunsaturated fatty acids in transgenic cereals
Abstracts / Journal of Biotechnology 208 (2015) S5–S120
Role of antioxidant phenolic compounds in plant responses to environmental stress Mohamad Al Hassan 1 , Monica Boscaiu 2 , Oscar Vicente 1,∗ 1
Institute of Plant Molecular and Cellular Biology (IBMCP), Universitat Politècnica de València, Valencia, Spain 2 Agroforestal Mediterranean Institute (IAM), Universitat Politècnica de València, Valencia, Spain E-mail address: [email protected] (O. Vicente). Adverse environmental conditions cause oxidative stress in plants by generation of “reactive oxygen species” (ROS), to which plants respond activating enzymatic and non-enzymatic antioxidant systems. Many phenolic compounds, especially flavonoids, are known antioxidants and efficient ROS scavengers in vitro; this activity appears to be the reason for their attributed beneficial effects for human health. There are evidences for the involvement of phenolics/flavonoids in plant responses to abiotic stress, mostly based on experiments with model species under controlled (but artificial) greenhouse conditions; yet their role in stress tolerance mechanisms in nature is still unclear. There are large quantitative and qualitative differences in antioxidant phenolics in plant taxa, which makes it difficult to generalise the results obtained for particular species. Moreover, phenolics fulfil many different biological functions in plants, which can mask their specific effects on the defense against environmental stress. Our strategy to assess the biological relevance of these secondary metabolites in abiotic stress tolerance mechanisms is based on the correlation between the levels of total phenolics and antioxidant flavonoids and the degree and type of stress, in plant material collected in the field from a relatively large number of plant species growing under varied environmental conditions (different habitats, several seasons throughout the year). Despite the aforementioned difficulties, we could detect statistically significant correlations of phenolics contents with altitude and with soil and atmospheric parameters associated to water stress, thus supporting a general, ecologically relevant function of antioxidant phenolic compounds in the mechanisms of response to environmental stress in plants. http://dx.doi.org/10.1016/j.jbiotec.2015.06.020 Establishment of a photosynthetic animal – Just a fiction? Juraj Krajcovic Department of Genetics, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia E-mail address: [email protected] (J. Krajcovic). Photosynthesis provides both the energy and matter for nearly all biotic processes. It has long been known that photosynthesis takes place in chlorophyll-containing plants, algae and some bacteria. The overwhelming amount of photosynthetic products is formed by special organelles of eukaryotes, the chloroplasts. Photosynthetic symbioses are presumably derived from initial trophic interactions between a heterotrophic host and photosynthetic prey. One of the key evolutionary events was an endosymbiosis between a heterotrophic eukaryote and a cyanobacterium, resulting in a primary chloroplast. Subsequently they have also moved between eukaryotes during additional rounds of secondary and tertiary endosymbioses of algal cells already possessing chloroplasts. Many otherwise non-photosynthetic eukaryotes are known to harbour transient internal photosynthetic symbionts, with varying degrees
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of stability, including some animals such as sea slugs, clams, sponges, corals, anemones, flatworms and ascidians. Animals containing green photobionts challenge the common perception that only plants are capable of capturing light energy to fix CO2 and generate reduced carbon compounds. There is an apparent absence of mutualist endosymbionts in vertebrates may be because of their adaptive immune system. Anyway, there are some recent studies showing that it is possible to engineer photosynthetic microorganisms to invade the cytoplasm of mammalian cells, including human ones having great potential in biotechnology and synthetic biology. Other experimental studies using synthetic ecosystems have suggested that it is feasible for organisms to establish mutually beneficial interactions. http://dx.doi.org/10.1016/j.jbiotec.2015.06.021 Modified biosynthesis of polyunsaturated fatty acids in transgenic cereals Ján Kraic 1,∗ , Daniel Mihálik 1 , Marcela Gubiˇsová 1 , Katarína Ondreiˇcková 1 , Lenka Klˇcová 3 , Tatiana Klempová 2 , Martina Hudcovicová 1 , Jozef Gubiˇs 1 , 2 ˇ Alˇzbeta Zˇ ofajová 1 , Milan Certík 1 NAFC-Research Institure of Plant Production, Piestany, Slovakia 2 Slovak University of Technology, Faculty of Chemical and Food Technology, Bratislava, Slovak Republic 3 Constantine The Philosopher University, Faculty of Natural Sciences, Nitra, Slovak Republic
E-mail address: [email protected] (J. Kraic). Cereals as the major food and feed supply are rich of proteins, carbohydrates, minerals, fiber, some vitamins as well as other compounds. However, they are deficient in essential polyunsaturated fatty acids (PUFAs). The modification of fatty acids biosynthesis in cereals is not possible by a traditional breeding approach based on hybridization and selection. Alternatively, specific biotechnological approaches such as genetic engineering could lead to an improvement of cereal seeds by a production of PUFAs. The Zygomycetes fungi could be helpful in this effort as natural producers of PUFAs. They provide relevant genes encoding enzymes (e.g. fatty acid desaturases) of the PUFAs biosynthesis pathway. Subsequently, the biotechnological approaches for the development of cereals synthesizing desired fatty acids include necessary in vitro and gene transfer methods. Although effective transformation of genes into the main cereals is much difficult in comparison with model plants and some other agricultural crops, introduction and expression of fungal delta-6 desaturase in barley and wheat plants has already been done in our experiments. Introduction and expression of gene originated from filamentous fungi have been confirmed at genomic, transcriptomic, and metabolomic levels. Transgenic barley and wheat plants were enriched with both the gamma-linolenic and stearidonic acids non-produced before. This biotechnological strategy offers enormous potential for the natural production of “tailor-made” functional cereals enriched with PUFAs in our case. Also can open novel possibilities for development, production, and utilization of improved cereal seeds attractive in a production of cereal-based functional foods with beneficial effect for a consumer, as well as in feed industry. http://dx.doi.org/10.1016/j.jbiotec.2015.06.022
Role of antioxidant phenolic compounds in plant responses to environmental stress Mohamad Al Hassan 1 , Monica Boscaiu 2 , Oscar Vicente 1,∗ 1
Institute of Plant Molecular and Cellular Biology (IBMCP), Universitat Politècnica de València, Valencia, Spain 2 Agroforestal Mediterranean Institute (IAM), Universitat Politècnica de València, Valencia, Spain E-mail address: [email protected] (O. Vicente). Adverse environmental conditions cause oxidative stress in plants by generation of “reactive oxygen species” (ROS), to which plants respond activating enzymatic and non-enzymatic antioxidant systems. Many phenolic compounds, especially flavonoids, are known antioxidants and efficient ROS scavengers in vitro; this activity appears to be the reason for their attributed beneficial effects for human health. There are evidences for the involvement of phenolics/flavonoids in plant responses to abiotic stress, mostly based on experiments with model species under controlled (but artificial) greenhouse conditions; yet their role in stress tolerance mechanisms in nature is still unclear. There are large quantitative and qualitative differences in antioxidant phenolics in plant taxa, which makes it difficult to generalise the results obtained for particular species. Moreover, phenolics fulfil many different biological functions in plants, which can mask their specific effects on the defense against environmental stress. Our strategy to assess the biological relevance of these secondary metabolites in abiotic stress tolerance mechanisms is based on the correlation between the levels of total phenolics and antioxidant flavonoids and the degree and type of stress, in plant material collected in the field from a relatively large number of plant species growing under varied environmental conditions (different habitats, several seasons throughout the year). Despite the aforementioned difficulties, we could detect statistically significant correlations of phenolics contents with altitude and with soil and atmospheric parameters associated to water stress, thus supporting a general, ecologically relevant function of antioxidant phenolic compounds in the mechanisms of response to environmental stress in plants. http://dx.doi.org/10.1016/j.jbiotec.2015.06.020 Establishment of a photosynthetic animal – Just a fiction? Juraj Krajcovic Department of Genetics, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia E-mail address: [email protected] (J. Krajcovic). Photosynthesis provides both the energy and matter for nearly all biotic processes. It has long been known that photosynthesis takes place in chlorophyll-containing plants, algae and some bacteria. The overwhelming amount of photosynthetic products is formed by special organelles of eukaryotes, the chloroplasts. Photosynthetic symbioses are presumably derived from initial trophic interactions between a heterotrophic host and photosynthetic prey. One of the key evolutionary events was an endosymbiosis between a heterotrophic eukaryote and a cyanobacterium, resulting in a primary chloroplast. Subsequently they have also moved between eukaryotes during additional rounds of secondary and tertiary endosymbioses of algal cells already possessing chloroplasts. Many otherwise non-photosynthetic eukaryotes are known to harbour transient internal photosynthetic symbionts, with varying degrees
S11
of stability, including some animals such as sea slugs, clams, sponges, corals, anemones, flatworms and ascidians. Animals containing green photobionts challenge the common perception that only plants are capable of capturing light energy to fix CO2 and generate reduced carbon compounds. There is an apparent absence of mutualist endosymbionts in vertebrates may be because of their adaptive immune system. Anyway, there are some recent studies showing that it is possible to engineer photosynthetic microorganisms to invade the cytoplasm of mammalian cells, including human ones having great potential in biotechnology and synthetic biology. Other experimental studies using synthetic ecosystems have suggested that it is feasible for organisms to establish mutually beneficial interactions. http://dx.doi.org/10.1016/j.jbiotec.2015.06.021 Modified biosynthesis of polyunsaturated fatty acids in transgenic cereals Ján Kraic 1,∗ , Daniel Mihálik 1 , Marcela Gubiˇsová 1 , Katarína Ondreiˇcková 1 , Lenka Klˇcová 3 , Tatiana Klempová 2 , Martina Hudcovicová 1 , Jozef Gubiˇs 1 , 2 ˇ Alˇzbeta Zˇ ofajová 1 , Milan Certík 1 NAFC-Research Institure of Plant Production, Piestany, Slovakia 2 Slovak University of Technology, Faculty of Chemical and Food Technology, Bratislava, Slovak Republic 3 Constantine The Philosopher University, Faculty of Natural Sciences, Nitra, Slovak Republic
E-mail address: [email protected] (J. Kraic). Cereals as the major food and feed supply are rich of proteins, carbohydrates, minerals, fiber, some vitamins as well as other compounds. However, they are deficient in essential polyunsaturated fatty acids (PUFAs). The modification of fatty acids biosynthesis in cereals is not possible by a traditional breeding approach based on hybridization and selection. Alternatively, specific biotechnological approaches such as genetic engineering could lead to an improvement of cereal seeds by a production of PUFAs. The Zygomycetes fungi could be helpful in this effort as natural producers of PUFAs. They provide relevant genes encoding enzymes (e.g. fatty acid desaturases) of the PUFAs biosynthesis pathway. Subsequently, the biotechnological approaches for the development of cereals synthesizing desired fatty acids include necessary in vitro and gene transfer methods. Although effective transformation of genes into the main cereals is much difficult in comparison with model plants and some other agricultural crops, introduction and expression of fungal delta-6 desaturase in barley and wheat plants has already been done in our experiments. Introduction and expression of gene originated from filamentous fungi have been confirmed at genomic, transcriptomic, and metabolomic levels. Transgenic barley and wheat plants were enriched with both the gamma-linolenic and stearidonic acids non-produced before. This biotechnological strategy offers enormous potential for the natural production of “tailor-made” functional cereals enriched with PUFAs in our case. Also can open novel possibilities for development, production, and utilization of improved cereal seeds attractive in a production of cereal-based functional foods with beneficial effect for a consumer, as well as in feed industry. http://dx.doi.org/10.1016/j.jbiotec.2015.06.022