Novel approaches to improving qualities of maize endosperm

Maize is a high yielding crop that provides a relatively high calorie source of food and feed, but focus on yield has not improved nutritional qualities. Some nutrients that are lacking in maize are iron and essential amino acids. In this dissertation some ways that genes from maize might be used to improve nutritional quality of maize are discussed, including improvement of bioavailable iron with maize globin and exploration of maize seed storage proteins. In addition, strategies to improve maize are explored, including breeding with mutations and transgenes and investigation of the effects of selection on transgenes. Maize globin was found to be as bioavailable as ferrous sulfate, both when used as a forticant added to maize flour and when expressed in maize with an endosperm specific promoter. These results indicate that maize globin could be used to biofortify maize with highly bioavailable iron. Assessment of seed storage proteins in maize inbreds, landraces, and teosintes found unique proteins in teosintes that may be moved into maize through biotechnology or breeding to improve amino acid balance. Investigation of the effects of ensiling on seed storage proteins in maize used as ruminant feed found that longer ensiling times degraded some seed storage proteins, which may make the starch more digestible, but inoculation with Lactobacillus did not have an effect. A variety of breeding methods can be used to improve qualities of maize. Maize transformed with a construct encoding green fluorescent protein controlled by a maize seed storage protein promoter was subjected to recurrent selection in order to increase transgene expression. This resulted in increased expression of the native gene with the same promoter, while unrelated traits were not changed. Backcrossing can be used to bring a mutation or transgene into a specific genetic background, while forward breeding can be used to improve characteristics of a line that carries a gene of interest

Recurrent Selection for Transgene Activity Levels in Maize Results in Proxy Selection for a Native Gene with the Same Promoter

High activity levels of a transgene can be very useful, making a transgene easier to evaluate for safety and efficacy. High activity levels can also increase the economic benefit of the production of high value proteins in transgenic plants. The goal of this research is to determine if recurrent selection for activity of a transgene will result in higher activity, and if selection for activity of a transgene controlled by a native promoter will also increase protein levels of the native gene with the same promoter. To accomplish this goal we used transgenic maize containing a construct encoding green fluorescent protein controlled by the promoter for the maize endosperm-specific 27kDa gamma zein seed storage protein. We carried out recurrent selection for fluorescence intensity in two breeding populations. After three generations of selection, both selected populations were significantly more fluorescent and had significantly higher levels of 27kDa gamma zein than the unselected control populations. These higher levels of the 27kDa gamma zein occurred independently of the presence of the transgene. The results show that recurrent selection can be used to increase activity of a transgene and that selection for a transgene controlled by a native promoter can increase protein levels of the native gene with the same promoter via proxy selection. Moreover, the increase in native gene protein level is maintained in the absence of the transgene, demonstrating that proxy selection can be used to produce non-transgenic plants with desired changes in gene expression

Genetic and biochemical differences in populations bred for extremes in maize grain methionine concentration

Background: Methionine is an important nutrient in animal feed and several approaches have been developed to increase methionine concentration in maize (Zea mays L.) grain. One approach is through traditional breeding using recurrent selection. Using divergent selection, genetically related populations with extreme differences in grain methionine content were produced. In order to better understand the molecular mechanisms controlling grain methionine content, we examined seed proteins, transcript levels of candidate genes, and genotypes of these populations. Results: Two populations were selected for high or low methionine concentration for eight generations and 40 and 56% differences between the high and low populations in grain methionine concentration were observed. Mean values between the high and low methionine populations differed by greater than 1.5 standard deviations in some cycles of selection. Other amino acids and total protein concentration exhibited much smaller changes. In an effort to understand the molecular mechanisms that contribute to these differences, we compared transcript levels of candidate genes encoding high methionine seed storage proteins involved in sulfur assimilation or methionine biosynthesis. In combination, we also explored the genetic mechanisms at the SNP level through implementation of an association analysis. Significant differences in methionine-rich seed storage protein genes were observed in comparisons of high and low methionine populations, while transcripts of seed storage proteins lacking high levels of methionine were unchanged. Seed storage protein levels were consistent with transcript levels. Two genes involved in sulfur assimilation, Cys2 and CgS1 showed substantial differences in allele frequencies when two selected populations were compared to the starting populations. Major genes identified across cycles of selection by a high-stringency association analysis included dzs18, wx, dzs10, and zp27. Conclusions: We hypothesize that transcriptional changes alter sink strength by altering the levels of methionine-rich seed storage proteins. To meet the altered need for sulfur, a cysteine-rich seed storage protein is altered while sulfur assimilation and methionine biosynthesis throughput is changed by selection for certain alleles of Cys2 and CgS1

Novel approaches to improving qualities of maize endosperm

Maize is a high yielding crop that provides a relatively high calorie source of food and feed, but focus on yield has not improved nutritional qualities. Some nutrients that are lacking in maize are iron and essential amino acids. In this dissertation some ways that genes from maize might be used to improve nutritional quality of maize are discussed, including improvement of bioavailable iron with maize globin and exploration of maize seed storage proteins. In addition, strategies to improve maize are explored, including breeding with mutations and transgenes and investigation of the effects of selection on transgenes. Maize globin was found to be as bioavailable as ferrous sulfate, both when used as a forticant added to maize flour and when expressed in maize with an endosperm specific promoter. These results indicate that maize globin could be used to biofortify maize with highly bioavailable iron. Assessment of seed storage proteins in maize inbreds, landraces, and teosintes found unique proteins in teosintes that may be moved into maize through biotechnology or breeding to improve amino acid balance. Investigation of the effects of ensiling on seed storage proteins in maize used as ruminant feed found that longer ensiling times degraded some seed storage proteins, which may make the starch more digestible, but inoculation with Lactobacillus did not have an effect. A variety of breeding methods can be used to improve qualities of maize. Maize transformed with a construct encoding green fluorescent protein controlled by a maize seed storage protein promoter was subjected to recurrent selection in order to increase transgene expression. This resulted in increased expression of the native gene with the same promoter, while unrelated traits were not changed. Backcrossing can be used to bring a mutation or transgene into a specific genetic background, while forward breeding can be used to improve characteristics of a line that carries a gene of interest.</p

Bio-art — the Transaesthetics of Bios

Bio-art — the Transaesthetics of BiosToday, the synthesis of scientific and technological progress achievements and aesthetic consciousness make it possible to speak about the bio-art phenomenon. Contemporary artists working in this field use aesthetic categories to explain/describe the nature of life, at the same time applying biological knowledge, materials and high technologies to art making. Since we are speaking about life as the bios, it would be appropriate to discuss bioaesthetics as the paradigm of beauty and discuss its rules, conventions and norms in living nature in the context of understanding a human being as a part of bios. The development of interdisciplinary scientific dialogue, extension of human mind map, establishment of nonlinear thinking, technology evolution as well as bioethical reflection — all these factors contribute to the transformation from the mosaic of postmodernism to the integral conception of the world. Having dealt with a vast number of bio-art manifestations, we have developed a convenient classification of bio-art with regard to perception channels and cognitive levels: visual and auditory, through literature and performance on the one hand and sensorimotor, mental and spiritual on the other. Thus, our work lies within the paradigm of anthropological, psychological and semiotic research on the range of problems of human dimension and the philosophical sentences in the eternal search for the answer to the question — “Where is the beginning and the end of humanity?”Bio-art — the Transaesthetics of BiosToday, the synthesis of scientific and technological progress achievements and aesthetic consciousness make it possible to speak about the bio-art phenomenon. Contemporary artists working in this field use aesthetic categories to explain/describe the nature of life, at the same time applying biological knowledge, materials and high technologies to art making. Since we are speaking about life as the bios, it would be appropriate to discuss bioaesthetics as the paradigm of beauty and discuss its rules, conventions and norms in living nature in the context of understanding a human being as a part of bios. The development of interdisciplinary scientific dialogue, extension of human mind map, establishment of nonlinear thinking, technology evolution as well as bioethical reflection — all these factors contribute to the transformation from the mosaic of postmodernism to the integral conception of the world. Having dealt with a vast number of bio-art manifestations, we have developed a convenient classification of bio-art with regard to perception channels and cognitive levels: visual and auditory, through literature and performance on the one hand and sensorimotor, mental and spiritual on the other. Thus, our work lies within the paradigm of anthropological, psychological and semiotic research on the range of problems of human dimension and the philosophical sentences in the eternal search for the answer to the question — “Where is the beginning and the end of humanity?

New Plant Engineering Techniques, R&D Investment, and International Trade

New Plant Engineering Techniques (NPETs) may significantly improve both production and quality of foods. Consumers and regulators around the world might be reluctant to accept such products, which may cripple adoption and global market penetration of these products. We develop a parsimonious economic model for R&D investment in food innovations to identify conditions under which NPET technology emerges in a context of international trade. The framework integrates consumers' willingness to pay (WTP) for the new food, the uncertainty of R&D processes, the associated regulatory cost of approval, and the competition between domestic and foreign products. With generic applicability, the model enables the quantitative analysis of new foods that could be introduced in markets and then traded across borders. We apply the framework to a hypothetical case of apples improved with NPETs. Simulation results suggest that import bans and high values of sunk costs can reduce R&D investment in NPETs to suboptimal levels