Genetic Modification Of Plants Research Articles

How genetic modification of roots affects rhizosphere processes and plant performance

Genetic modification of plants has become common practice. However, root-specific genetic modifications have only recently been advocated. Here, a review is presented regarding how root-specific modifications can have both plant internal and rhizosphere-mediated effects on aboveground plant properties and plant performance. Plant internal effects refer to pleiotropic processes such as transportation of the modified gene product. Rhizosphere-mediated effects refer to altered plant-rhizosphere interactions, which subsequently feed back to the plant. Such plant-soil feedback mechanisms have been demonstrated both in natural systems and in crops. Here how plant internal and rhizosphere-mediated effects could enhance or counteract improvements in plant properties for which the genetic modification was intended is discussed. A literature survey revealed that rice is the most commonly studied crop species in the context of root-specific transgenesis, predominantly in relation to stress tolerance. Phytoremediation, a process in which plants are used to clean up pollutants, is also often an objective when transforming roots. These two examples are used to review potential effects of root genetic modifications on shoots. There are several examples in which root-specific genetic modifications only lead to better plant performance if the genes are specifically expressed in roots. Constitutive expression can even result in modified plants that perform worse than non-modified plants. Rhizosphere effects have rarely been examined, but clearly genetic modification of roots can influence rhizosphere interactions, which in turn can affect shoot properties. Indeed, field studies with root-transformed plants frequently show negative effects on shoots that are not seen in laboratory studies. This might be due to the simplified environments that are used in laboratories which lack the full range of plant-rhizosphere interactions that are present in the field.

Unintended effects of genetic modifications and methods of their analysis in plants

The problem of unintended effects, which may be caused by genetic modification of plants, is analyzed. The factors that provoke the occurrence of unintended effects in genetically engineered plants, the consequences caused by the influence of these factors, and the possibility to minimize such effects by the use of improved methods of genetic engineering are discussed. Modern methodological approaches that can be applied to the analysis of unintended effects considered as a stage of safety assessment of transgenic plants, especially the methods of molecular profiling with the use of different “-omic” technologies, are described.

Meeting report: BioVision – a sumptuous table of food‐for‐thought

Meeting report: <i>BioVision</i> – a sumptuous table of food‐for‐thought

Induction of male sterility in transgenic chrysanthemums (Chrysanthemum morifolium Ramat.) by expression of a mutated ethylene receptor gene, Cm-ETR1/H69A, and the stability of this sterility at varying growth temperatures

Chrysanthemum (Chrysanthemum morifolium Ramat.) is one of the most popular ornamental flowers in the world, and many agronomic traits have recently been introduced to chrysanthemum cultivars by gene transformation. Concerns have been raised, however, regarding transgene flow from transgenic plants to wild plants. In early studies, ethylene receptor genes have been used for genetic modification in plants, such as flower longevity and fruit ripening. Recently, overexpression of ethylene receptor genes from melon (CmETR1/H69A) caused delayed tapetum degradation of the anther sac and a reduction in pollen grains. We therefore introduced the ethylene receptor gene into chrysanthemums to induce male sterility and prevent transgene flow via pollen. The chrysanthemum cultivar Yamate shiro was transformed using a disarmed strain of Agrobacterium tumefaciens, EHA105, carrying the binary vector pBIK102H69A, which contains the CmETR1/H69A gene. A total of 335 shoots were regenerated from 1,282 leaf discs on regeneration medium (26.1%). The presence of the Cm-ETR1/H69A gene was confirmed in all of the regenerated plantlets by Southern blot analysis. These genetically modified (GM) plants and their non-GM counterparts were grown in a closed greenhouse and flowered at temperatures between 10 and 35°C. In 15 of the 335 GM chrysanthemum lines, the number of mature pollen grains was significantly reduced, particularly in three of the lines (Nos. 91, 191 and 324). In these three lines, pollen grains were not observed at temperatures between 20 and 35°C but were observed at 10 and 15°C, and mature pollen grains were formed only at 15°C. In northern blot analyses, expression of the CmETR1/H69A gene was suppressed at low temperatures. This phenomenon was observed as a result of both the suppression of CmETR1/H69A expression at low temperatures and the optimal growth temperature of chrysanthemums (15–20°C). Furthermore, the female fertility of these three GM lines was significantly lower than that of the non-GM plants. Thus, the mutated ethylene receptor is able to reduce both male and female fertility significantly in transgenic chrysanthemums, although the stability of male and/or female sterility at varying growth temperatures is a matter of concern for its practical use.

Ageing and irradiance enhance vitamin E content in green edible tissues from crop plants

Tocopherol (vitamin E) is an antioxidant essential in human nutrition. Several approaches have aimed to enhance tocopherol content in crops by the genetic modification of plants, a practice that generates some social concern. As tocopherol accumulates with leaf age in some wild plants and the antioxidant mechanisms respond with flexibility to stress conditions, it is hypothesised that tocopherol content can be increased in edible plants by the manipulation of harvesting time and growth conditions, in particular irradiance. Ontogenic changes in tocopherol concentration have been studied in photosynthetic tissues of edible leaves (lettuce, spinach, corn salad and dandelion) and green fruits (cucumber and pepper). In all species, tocopherol content increased with tissue age. Spinach showed the fastest rate of tocopherol accumulation, and growth at higher irradiance had a synergistic effect on the rate of accumulation. The same irradiance dependence of this accumulation was observed in fruits, but a final decrease with senescence occurred in cucumber. This study demonstrates that the content of tocopherol in vegetables can be notably enhanced (or reduced) by simply selecting the appropriate harvesting time and/or by manipulating the environmental conditions during the growth period.

Issues in the Political Economy of Agricultural Biotechnology

Agricultural biotechnology is typically analyzed critically by means of a political ecological focus on the science and its ecological implications – agbio science as a radical, and ‘non‐natural’, break with ‘normal’ trajectories for ‘new plant science’. Surprisingly, less attention has been paid to a range of key political economic issues, many of which were important in the last big food production technology ‘revolution’, the Green Revolution. This paper will focus on three areas of political economy. First, we discuss the corporate drivers of agricultural biotechnology, and examine whether these drivers have already set the technology so that it cannot be changed. Second, we investigate the present economics and technology of genetic modification in plants, and its possible future. Third, we examine empirical evidence for alternative visions of the technology.

Detection strategies for non-authorized GMO products on the European market

Import and planting of biotech crops is strictly regulated in Europe. In order to observe these strict regulations, an efficient surveillance of the European market is required. In Europe, data on authorised biotech crops from foreign countries are on hand, however, only scarce information on non-authorised biotech crops is available. Experience of the last years has shown that non-authorized biotech crops (e.g. biotech-papaya, Bt10-maize, LL601-rice and Bt63-rice) were detected on the European market. The Bavarian Health and Food Safety Authority is responsible for the detection of illegal imports and for labelling control of Food and Feed in Bavaria (Germany). The quantitative real-time PCR is the method of choice for the detection of genetic modifications in plants on DNA level. Therefore, data on novel DNA constructs and event-specific detection methods need to be gathered to assure the surveillance of the market for non-authorised GMO.

Detection strategies for non-authorized GMO products on the European market

AbstractImport and planting of biotech crops is strictly regulated in Europe. In order to observe these strict regulations, an efficient surveillance of the European market is required. In Europe, data on authorised biotech crops from foreign countries are on hand, however, only scarce information on non-authorised biotech crops is available. Experience of the last years has shown that non-authorized biotech crops (e.g. biotech-papaya, Bt10-maize, LL601-rice and Bt63-rice) were detected on the European market. The Bavarian Health and Food Safety Authority is responsible for the detection of illegal imports and for labelling control of Food and Feed in Bavaria (Germany). The quantitative real-time PCR is the method of choice for the detection of genetic modifications in plants on DNA level. Therefore, data on novel DNA constructs and event-specific detection methods need to be gathered to assure the surveillance of the market for non-authorised GMO.

Coenzyme Q10 Contents in Foods and Fortification Strategies

Coenzyme Q10 (CoQ 10 ) is an effective natural antioxidant with a fundamental role in cellular bioenergetics and numerous known health benefits. Reports of its natural occurrence in various food items are comprehensively reviewed and critically evaluated. Meat, fish, nuts, and some oils are the richest nutritional sources of CoQ 10 , while much lower levels can be found in most dairy products, vegetables, fruits, and cereals. Large variations of CoQ 10 content in some foods and food products of different geographical origin have been found. The average dietary intake of CoQ 10 is only 3–6 mg, with about half of it being in the reduced form. The intake can be significantly increased by the fortification of food products but, due to its lipophilicity, until recently this goal was not easily achievable particularly with low-fat, water-based products. Forms of CoQ 10 with increased water-solubility or dispersibility have been developed for this purpose, allowing the fortification of aqueous products, and exhibiting improved bioavailability; progress in this area is described briefly. Three main fortification strategies are presented and illustrated with examples, namely the addition of CoQ 10 to food during processing, the addition of this compound to the environment in which primary food products are being formed (i.e. animal feed), or with the genetic modification of plants (i.e. cereal crops).

The Karlson Lecture. Phytoecdysteroids: What use are they?

Phytoecdysteroids are analogues of arthropod steroid hormones found in plants, where they deter predation by non-adapted predators. There is potential to exploit this to develop new strategies for pest control, either by using ecdysteroids as lead molecules for the design of novel pest control agents or by alteration of ecdysteroid levels/profiles in crop plants through plant breeding or genetic modification. However, it is other properties of phytoecdysteroids that have led to a rapid recent increase in scientific and commercial interest in these molecules. They are apparently non-toxic to mammals and a wide range of beneficial pharmacological (adaptogenic, anabolic, anti-diabetic, hepatoprotective, immunoprotective, wound-healing, and perhaps even anti-tumour) activities is claimed for them. In particular, this has led to a large (and unregulated) market for ecdysteroid-containing preparations for body-builders, sportsmen, and pets, among others. Ecdysteroids are also being considered as nutraceutical additives to food products. Further, ecdysteroids are good candidates as elicitors for gene-switch systems to be used in medical gene therapy and research applications. In this article, I review the applications of phytoecdysteroids and assess their future potential.

Detecção e quantificação de soja geneticamente modificada em géneros alimentícios, comercializados em Portugal, para consumo humano

Biotechnology allows plant and animal genetic modification, leading to genetic modified organisms (GMO). The GMO related benefits and risks are still surrounded in controversy, reason why the consumer has the right to decide about its consumption. The aim of this work is to detect and quantify genetically modified soy in foodstuffs. In that sense, 11 samples from two different lots of the same foodstuff’s brand, which contain soy, for human consumption were analysed. Real time PCR method was used to detect and quantify transgenic DNA. From all the samples analysed, 7 were negative (63.6%) and 4 positive (36.4%) for the DNA detection from transgenic soy, corresponding to 3 foodstuffs: soy milk, flour and granulated. The DNA quantities from transgenic soy vary from 0.07% (granulated soy) to 0.22% (soy flour), suggesting environmental contamination because they are below 0.4%.

CISGENESIS IS A PROMISING APPROACH FOR FAST, ACCEPTABLE AND SAFE BREEDING OF PIP FRUIT

Introgression of traits from wild germplasm into pip fruit cultivars by means of classical breeding is painstakingly slow. Introgression of e.g., the apple scab resistance gene Vf from Malus floribunda 821 into marketable high quality apple cultivars took approximately 50 years. In the mean time the Vf resistance is being broken down in Europe. For durable resistance, different resistance genes should be accumulated. However, this may take another series of decades. This slow tempo is caused mainly by the long juvenile period of apple and the phenomenon that not only the allele of interest is inherited by the progeny, but also hundreds of unwanted alleles. The process would be much faster if only the allele of interest was inserted, without unwanted alleles. This can be achieved by cisgenesis. We defined cisgenesis as genetic modification of plants, inserting alleles of the plant itself or from crossable relatives. The allele should contain its native introns and should be flanked by its native promoter and terminator in sense-orientation. If the plant is equipped with foreign genes from outside the gene pool of the conventional breeder, the plant is named transgenic. Inquiries indicate that cisgenic plants are more acceptable to consumers than transgenic plants. As the phenotypic result of cisgenesis can, in principle, also be obtained by means of conventional breeding or translocation breeding, cisgenic plants are as safe as plants from conventional breeding or mutation breeding. Therefore we have proposed to treat cisgenic plants like conventionally bred plants, by exempting cisgenic plants from the GMO regulation. The number of isolated, functionally analysed genes and their alleles from fruit tree crops is increasing. Also technologies are available for introduction of these alleles without leaving selection genes behind. Cisgenesis is combining the knowledge of native alleles with marker free technologies. Cisgenesis is a promising path for utilizing the wealth of knowledge on plant genes to the benefit of the society in a fast, safe, and acceptable way.

Adventitious shoot regeneration from the leaves of in vitro grown ‘Zhongli 1’ pear (Pyrus spp.)

The pear (Pyrus spp.) is one of the most important temperate fruit crops. The technique of adventitious shoot regeneration from leaves is considered to be one of the shortcuts in the research on pear genetic modification and cellular engineering, which, however, has not been widely used. As the regeneration frequency of pear leaves is usually very low, the research on adventitious shoot regeneration from pear leaves is eagerly needed. In this experiment, the factors affecting shoot and bud regeneration from the leaves of ‘Zhongli 1’ pear were studied, and an efficient protocol for shoot regeneration was established. The results showed that different types of basic media, different combinations of plant growth regulators, leaf placement on medium, periods of dark culture and the use of silver nitrate (AgNO3) on culture media all significantly affected the adventitious shoot regeneration frequency of ‘Zhongli 1’ pear. The details are as follows: (1) Among three kinds of basic media, NN69 was better for ‘Zhongli 1’ shoot regeneration, followed by half (½) MS, while full MS had no effect on shoot regeneration; (2) Thidiazuron (TDZ) was better than 6-benzylaminopurine (6-BA) for ‘Zhongli 1’ regeneration, with an optimal concentration of 1.5 mg · L−1, and the regeneration rate under this concentration could reach 85%, with 2.72 buds per leaf. 0.5 mg · L−1 indole-3-butyric acid (IBA), which induced a higher regeneration frequency, was a better choice for pear regeneration compared with 0.3 mg · L−1 naphthaleneacetic acid (NAA). Among the different combinations of plant growth regulators, TDZ + IBA was better for inducing high regeneration frequency; (3) The abaxial surface of leaves touching the medium was beneficial for leaves to uptake nutrients from the medium, and because of that, the regeneration frequency of leaves was significantly higher than that of leaves touching the medium with their adaxial surfaces (obverse side of leaf); (4) Dark culture was necessary for bud regeneration, and the best duration for dark culture of ‘Zhongli 1’ pear was 21 days; (5) The addition of 1.0 mg · L−1 AgNO3 into the culture medium could promote adventitious shoot regeneration significantly. A high adventitious shoot regeneration frequency was obtained in this research, which will be beneficial for further research on efficient and stable in vitro plant regeneration systems and genetic modification of pear.

Beyond Equal: From Same But Different to the Doctrine of Substantial Equivalence

A same-but-different dichotomy has recently been encapsulated within the ill-defined concept of “substantial equivalence”. By invoking this concept the genetically modified organism (GMO) industry has escaped the rigors of safety testing that might otherwise apply. The curious concept of “substantial equivalence” grants a presumption of safety to GMO food. This presumption has yet to be earned, and has been used to constrain labelling of both GMO and non-GMO food. It is an idea that well serves corporatism. It enables the claim of difference to secure patent protection, while upholding the contrary claim of sameness to avoid labelling and safety scrutiny. It offers the best of both worlds for corporate food entrepreneurs, and delivers the worst of both worlds to consumers. The term “substantial equivalence” has established its currency within the GMO discourse. As the opportunities for patenting food technologies expand, the GMO recruitment of this concept will likely be a dress rehearsal for the developing debates on the labelling and testing of other techno-foods - including nano-foods and clone-foods.

Cisgenesis, a New Tool for Traditional Plant Breeding, Should be Exempted from the Regulation on Genetically Modified Organisms in a Step by Step Approach

Modern potato breeding requires over 100,000 seedlings per new variety. Main reasons are (1) the increasing number of traits that have to be combined in this tetraploid vegetatively propagated crop, and (2) an increasing number of traits (e.g., resistance to biotic stress) originates from wild species. Pre-breeding by introgres- sion or induced translocation is an expensive way of transferring single traits (such as R-genes, coding for resistance to biotic stress) to the cultivated plant. The most important obstacle is simultaneous transfer of undesired neighbouring alien alleles as linkage drag. Stacking several genes from different wild sources is increasing this linkage drag problem tremendously. Biotechnology has enabled transformation of alien genes into the plant. Initially, transgenes were originating mainly from microorganisms, viruses or non-crossable plant species, or they were chimeric. Moreover, selection markers coding for antibiotic resistance or herbicide resistance were needed. Transgenes are a new gene source for plant breeding and, therefore, additional regulations like the EU Directive 2001/18/EC were developed. Because of a strong opposition against genetic modification of plants in Europe, the application of this Directive is strict, very expensive, hampering the introduction of genetically modified (GM) crops and the use of this technology by small and medium-sized enterprises (SMEs). Currently, GM crops are almost the exclusive domain of multinationals. Meanwhile, not only transgenes but also natural genes from the plant species itself or from crossable plant species, called cisgenes, are available and the alien selection genes can be avoided in the end product. This opens the way for cisgenic crops without alien genes. The existing EU directive for GM organisms is not designed for this new development. The cisgenes belong to the existing breeders' gene pool. The use of this classical gene pool has been regulated already in

Public approval of plant and animal biotechnology in South Korea: an ordered probit analysis

AbstractThis study analyzes predictors of South Korean public acceptance of the use of biotechnology to create genetically modified food products. Results indicate that those consumers with above average knowledge of specific outcomes of genetic modification were more likely to approve of the use of plant or animal genetic modification for the creation of new food products than those with inaccurate or no knowledge. Moreover, younger South Korean consumers were more likely than older consumers to approve of the use of biotechnology to create both plant and animal based foods. Further, the study produced evidence of different levels of approval of biotechnology among consumers from different residential areas, income levels and political affiliation. Thus, those living in cities, those with incomes above 40 million Won, and those who described themselves as having a liberal political affiliation were found to have a higher approval level for animal biotechnology. [JEL Classification: Q13, M31, D12] © 2008 Wiley Periodicals, Inc.

Intervening Effects of Knowledge, Morality, Trust, and Benefits on Support for Animal and Plant Biotechnology Applications

Data from a regional Southwest telephone survey in the United States (N= 432) were used to examine the intervening effects of knowledge, morality, trust, and benefits on support for animal and plant biotechnology applications. Results showed that perceptions of agricultural biotechnologies varied by the two applications-animals and plants. Respondents reported higher opposition to the genetic modification of animals, which is consistent with prior research. Results also indicated that morality and perceived benefits directly affected support for both animal and plant applications, but trust and knowledge only had indirect effects. Morality and perceived benefits accounted for most of the variance explained among the intervening variables. The effects of trust were mediated through perceived benefits. The effects of knowledge on support were mediated primarily through trust. The influence of sociodemographic and consumer behavior variables varied by application. Results lend support to several theoretical notions. First, the significance of perceived benefits supports that there is an inverse relationship between benefits and risks. Second, moral objections may outweigh perceived benefits for specific applications, and the genetic modification of animals is deemed to be more morally unacceptable than the genetic modification of plants. These findings demonstrate the need to understand more thoroughly the moral and ethical issues surrounding novel technologies. Third, this research supports the claim that trust is not a powerful predictor of perceptions of technological products, which is contrary to most risk perception research.

GENETICALLY MODIFIED FOODS IN NIGERIA: A long-lasting solution to hunger?

The application of biotechnology in the genetic modification of plants in food production has ledto the appearance of genetically modified foods (GMFs) in the marketplace. From inception, thesubject of GMFs food has been controversial. The use of biotechnology to enhance nutritionalvalue has raised a number of fundamental questions about genetically modified foods or plants allover the world. In spite of these controversies, GMF has been presented as the ultimate weaponagainst hunger in Africa, and other developing countries. While the world debates on whether ornot to endorse genetically modified food in most of Western Europe and give it the acceptance italready enjoys in the United States, we are totally oblivious of the fact that genetically modifiedfood has crept into Nigeria. Nigeria has been a recipient of food aid from countries like theUnited States, that are renowned for producing genetically modified foods. In 2004, Nigeria signeda Memorandum of Understanding (MoU) with the United States government agreeing to supportGM crops. Are GMFs really a good substitute for the natural and traditional foods? Are thebenefits of GM crops as strong as claimed by pro-biotech interests? If GM crops are safe,economically profitable, and environmentally friendly, why then has there been so much opposition,concern and controversy in recent years? If the scenario is so good, if so many millions of farmersand consumers are benefiting, if the increase in GM crops is so impressive, and if poverty,malnutrition and hunger have been alleviated in developing countries, why then have somegovernments imposed bans and why are consumers opposing those products in many places aroundthe world? Is there any substance in these arguments against GMFs? This paper discusses theseissues using Nigeria as a case study. We concluded that GMFs may not be the ultimate solution tohunger and poverty in a developing country like Nigeria.

Metabolomic technologies and their application to the study of plants and plant–host interactions

Metabolomics is perhaps the ultimate level of post-genomic analysis as it can reveal changes in metabolite fluxes that are controlled by only minor changes within gene expression measured using transcriptomics and/or by analysing the proteome that elucidates post-translational control over enzyme activity. Metabolic change is a major feature of plant genetic modification and plant interactions with pathogens, pests, and their environment. In the assessment of genetically modified plant tissues, metabolomics has been used extensively to explore by-products resulting from transgene expression and scenarios of substantial equivalence. Many studies have concentrated on the physiological development of plant tissues as well as on the stress responses involved in heat shock or treatment with stress-eliciting molecules such as methyl jasmonic acid, yeast elicitor or bacterial lipopolysaccharide. Plant-host interactions represent one of the most biochemically complex and challenging scenarios that are currently being assessed by metabolomic approaches. For example, the mixtures of pathogen-colonised and non-challenged plant cells represent an extremely heterogeneous and biochemically rich sample; there is also the further complication of identifying which metabolites are derived from the plant host and which are from the interacting pathogen. This review will present an overview of the analytical instrumentation currently applied to plant metabolomic analysis, literature within the field will be reviewed paying particular regard to studies based on plant-host interactions and finally the future prospects on the metabolomic analysis of plants and plant-host interactions will be discussed.

Biorefinery, the Bridge between Agriculture and Chemistry

The depletion in fossil feedstocks, increasing oil prices and the ecological problems associated with CO2 emissions are forcing the development of alternative resources for energy (heat and electricity), transport fuels and chemicals: the replacement of fossil resources with CO2 neutral biomass. When used in combination with environmentally sound production and processing techniques, the use of biomass can be seen as a sustainable alternative to conventional feedstocks. The production of chemicals utilises more effectively the intrinsic biomass (chemical) structure than the production of fuels or electricity from biomass does. The production of chemicals from biomass also saves more fossil energy than producing just energy. For example, some amino acids obtained from grass are very suitable starting materials for highly functionalized chemicals that are traditionally prepared from petrochemistry. Economical production routes of chemicals from biomass require large scale substitution of (bulk) chemicals which connects to current approaches and facilities (process integration) of the petrochemical industries to convert crude oil into chemical building blocks. Genetic modification of plants will increase the potential of biomass in the chemical industry because it allows an increase in the concentrations of the required (bio-)chemical pre-cursors e.g. amino acids, present. It will also be discussed how small scale (pre)processing of the biomass can be advantageous over large scale processing. This is because of lower transportation costs but also the opportunity to use process-integrations that can not be used on large scale. These integrations yield high efficiencies of energy utilization but require improvement on social or organisational levels