Grain Quality

Grain yield and quality depend on complex physiological processes occurring during plant development. However, protein content is a major determinant of the feed value of cereal grains. The protein content of wheat can be increased by conventional breeding, but not without compromising yield, so genetic engineering approaches have been suggested as having some potential in this context (see also Chap. 11). In an attempt to channel greater amounts of major substrates of protein biosynthesis into...

Native Markers for Intragenic Transformation

Various studies have shown that some plant genes themselves can be used as transformation markers. For instance, the acetohydroxyacid synthase gene from Arabidopsis has been used to develop intragenic Arabidopsis plants displaying chlorsulfuron tolerance (Conner et al. 2007). Another interesting native marker system is based on protoporphyrinogen oxidase genes. When the plastidic proto-porphyrinogen I oxidase gene from Arabidopsis was overexpressed under the control of the cauliflower mosaic...

Optimization of DNA Delivery

Particle bombardment, as with many of the DNA introduction methods, is rough on the target cells, as the integrity of the cell must be compromised to introduce the large DNA molecule. To get a more accurate picture of the scale of participants, the particles that enter the cell are in the range 0.6-1.0 mm while the target plant cells are usually 20-30 mm. If multiple particles or clumps of particles enter the same cell, damage to the target tissue increases. Ultimately, transient expression...

Introduction

Crops are attacked by animal pests and nematodes, causing considerable economic losses worldwide. The global yield loss, e.g. due to herbivorous insects varies between 5 and 30 depending on the crop species, while the estimated worldwide losses due to plant parasitic nematodes are about US 125 billion annually (Chitwood 2003). Root-knot nematodes like Meloidogyne incognita infect thousands of plant species, resulting in poor fruit yield, stunted growth, wilting and susceptibility to other...

Conclusions

Traditional methods in plant breeding rely on random genome modifications and are often difficult to apply to either eliminate undesirable features or activate dormant traits. This issue is effectively addressed by precisely recombining native elements in vitro and inserting the resulting expression cassettes into plants using marker-free and all-native DNA transformation. The intragenic method is exemplified by potato varieties displaying enhanced flavor and tolerance against black spot bruise...

Flavonoids

Flavonoids are phenolic compounds derived ultimately from phenylalanine which impart much of the color and flavor of fruits, vegetables, nuts and seeds. The first committed step in flavonoid biosynthesis is the conversion of the precursor 4-coumaroyl-CoA into chalcone by the enzyme chalcone synthase. Chalcone is then derivatized in a series of enzymatic steps to eventually form different classes of flavonoids, such as flavanones, dihydroflavonols and finally to the anthocyanins, the major...

Overview of Adoption

Since the commercial introduction of genetically modified crops in 1996 (for methods, see Chaps. 1, 2), the area planted to these cultivars has increased globally at an increasing rate (Anonymous 2006). In 2006, approximately 100 million hectares of genetically modified herbicide-resistant crops were planted worldwide and an estimated 80 had the genetically modified trait conferring glyphosate resistance (Service 2007). The use of these cultivars increased an estimated 12 in 2007 and...

Reducing the Risk of Transgene Silencing

Strategies to reduce the occurrence of homology-dependent transgene silencing include selection of single-copy transformants, site-specific recombination to remove repeat structures at transgene loci or to target transgenes to pre-selected integration sites that are favorable to transgene expression, and avoidance of sequence duplicates (e.g. promoters) within the transgene cassette (reviewed by Butaye et al. 2005). A number of precautions may also minimize the risk of single-copy transgene...

Protein Based Biomaterials

Protein-based biomaterials have a wide area of application, ranging from tissue engineering, drug carriers, coatings and glues to elastomers and fibres, dispersants, thickeners and additives to hydrogels. Two important target proteins are described here in detail fibrous proteins (e.g. spider silk) and non-ribosomally produced poly-amino acids like cyanophycin. Fibrous proteins contain short blocks of repeated amino acids and can be regarded as elaborate block co-polymers with unique...

Osmoprotectants and Metabolite Engineering

Abiotic stress such as dehydration, salt or freezing perturbs the cellular metabolism, as pointed out in numerous physiological experiments using many different plant species (Ingram and Bartels 1996 Bartels and Sunkar 2005). Therefore research strategies have been designed to counteract the metabolic imbalance provoked by abiotic stressors. It is implied in the research strategy that engineering metabolism may counteract negative consequences of stress only within a certain range. Another...

Agrobacterium Plant Interactions

The molecular mechanisms for the T-DNA transfer process have been described in detail in numerous excellent review articles (Zambryski 1992 Tzfira and Citovsky 2006) and are not presented again here. But, in order to better appreciate transformation methods that are Agrobacterium-based, it is best to have a basic understanding of the interaction of the bacterium with the target plant cells. In order to transfer its T-DNA to the plant cell, the bacteria must obviously be in very close proximity...

Drought and Salinity

Drought represents the single most limiting environmental factor to crop productivity worldwide. Its occurrence is frequently associated with soil salinity, which occurs naturally but has all too often been induced by poor irrigation practices. Plants respond to drought and salinity in many ways. The engineering of stress tolerance requires the identification and functional analysis of the key genes involved in the plant response. Gene expression is altered by the imposition of stress, and some...

Pathogenesis Related Proteins

The expression of the PR proteins is up-regulated upon the recognition of a pathogen (Bol et al. 1996). The PRs do not prevent the establishment of an interaction between the host and the pathogen, but rather attenuate fungal reproduction. Some PR proteins are thaumatin- or thionin-like, and others have glucanase or chitinase or peroxidase activity. The over-expression of some of these genes in the Triticeae has achieved enhanced basal resistance to various pathogenic fungi. Chitinases and...

Intragenic Tomato S esculentum Concentrating the Quality Potential of Tomato into its Fruit

Tomato is one of the most important horticultultural crops and represents an important source of vitamins, minerals, and antioxidants. Intragenic methods for tomato were first applied to redesign Calgene's FlavrSavr. The transgenic crop contained an extended Agrobacterium T-DNA region with an extra copy of the polygalacturonidase (Pg) gene inserted in the antisense orientation between the 35S promoter of cauliflower mosaic virus and the terminator of the Agrobacterium tml gene. It also carried...

Commercial Use of Male Sterility

A number of CMS systems have been and are being used in traditional plant breeding in order to generate hybrid varieties. From the many potential procedures for obtaining transgenic male sterility, only a few have been developed so far for commercially available crops. A compilation of these crops is given in Table 14.1. The events include several in canola, one in chicory, and three in maize. In almost all cases, the Barnase Barstar system is being employed, with the notable exception of a DNA...

Transgene Expression Systems

Appropriate promoters capable of effectively driving transgene expression are of central importance for the genetic engineering of plants. Many of the promoters isolated and characterized to date have originated from dicotyledonous species such as Arabidopsis thaliana, and since the experience has been that most of these promoters are not effective in a monocotyledonous host, so the choice of promoters for the cereals remains relatively limited. Ubiquitous transgene expression in the Triticeae...

Production of Recombinant Proteins

Crop plants offer an inexpensive and convenient production system for high value recombinant molecules, an approach currently termed molecular farming (see Chaps. 12, 13). The Triticeae cereals have some specific advantages in this context (Ma et al. 2003). Firstly, the grain itself constitutes a natural storage organ, which can be composed of up to 20 protein. Second, breeding and cultivation of these cereals is well advanced, and commercial yields of up to 10 t ha are not uncommon under...

Citrus Species

The genus Citrus includes several species of economic importance as sweet oranges (C. sinensis L.), mandarins (C. reticulata Blanco, C. deliciosa Ten.), satsumas (C. unshiu Marc.), clementines (C. clementina hort. ex Tanaka), grapefruits (C. paradisi Macfad.), pummelos (C. grandis L. Osbeck), lemons (C. limon L. Burm. f.) and limes (C. aurantifolia Christm. Swingle). Citrus grown in tropical and subtropical regions is the largest fruit crop in the world. Trifoliate orange (Poncirus trifoliate...

Cytoplasmic Male Sterility

Cytoplasmic Male Sterility

The mitochondrion serves essential functions as the centre of energy metabolism in developing eukaryotic organisms. Pollen development in plants appears to be particularly influenced by mitochondrial function. Rearrangements of mitochondrial DNA that lead to unique chimeric genes sometimes result in an inability of the plant to produce fertile pollen Fig. 14.1 . This process, known as cytoplasmic male sterility CMS , is particularly useful for the production of hybrid varieties for increased...

Herbicide Resistance

Herbicide resistance is not a topic or concern specifically focused upon the relatively recent introduction and adoption of genetically modified crops. In fact, the first case of herbicide resistance in weeds was reported in the scientific literature in 1970, but the occurrence of evolved resistance to herbicides in plants was suggested in 1956 Harper 1956 Ryan 1970 . Since the original report, over 300 herbicide-resistant weed biotypes in more than 180 different plant species have been...

Silicon Carbide Whiskers

Silicon carbide whiskers are long thin rigid microscopic rods 1 mm wide, 20-30 mm long that are used in the ceramics industry. They can be used as a vehicle for plant cell transformation when they are added to a mixture of plant cells and DNA and subsequently shaken at high speed Kaeppler et al. 1990 . Although silicon carbide whiskers were originally used with a laboratory vortexer, the back-and-forth motion obtained with a paint can mixer may work as well or better. The basic concept behind...

Alternative Systems

The rising demand both from the authorities and the public for genetically modified plants containing only foreign sequences needed for the immediate function encouraged the development of alternative systems, including Subsequent elimination of marker genes by co-transformation techniques, trans-poson usage, specific recombination systems or homologous recombination Marker-free transformation without usage of any selection marker Combinations of different systems, e.g. usage of screenable...

Transgenic Plant Strategies for Enhanced Drought Stress Tolerance in Crop Plants

Plants have evolved adaptive strategies to cope with abiotic stress conditions, such as drought. The plant stress response can be divided into perception and transduc-tion of environmental cues through signalling components, resulting in activation of stress-related genes and synthesis of diverse proteins that function in physiological and metabolic responses. Well characterized proteins involved in the protection of plant cells from dehydration stress damage include chaperones, osmotic...

References

Allen MM 1984 Cyanobacterial cell inclusions. Ann Rev Microbiol 38 1-25 Altman GH, Diaz F, Jak ba C, Calabro T, Horan RL, Chen J, L H, Richmond J, Kaplan DL 2003 Silk-based biomaterials. Biomaterials 24 401-416 Amber IJ, Hibbs JB, Taintor RR, Vavrin Z 1988 The L-arginine dependent effector mechanism is induced in murine adenocarcinoma cells by culture supernatant from cytotoxic activated macrophages. J Le k Biol 43 187-192 Arai Y, Nakashita H, Suzuki Y, Kobayashi K, Shimiz T, Yas da M, Doi Y,...

Top Fruit

Bpmads4 Early Flowering Flachowsky

The domesticated apple Malus domestica Borkh. is the most important pome-fruit worldwide. It ranked fourth within the fruit crops in 2006 behind bananas, grapes and citrus, with approximately 64 million t produced on 4.7 million ha http faostat.fao.org . The genus Malus apples comprises approximately 55 species, including M. domestica Borkh. and numerous wild species Phipps et al. 1990 . Only the domesticated apple is economically important. All Malus species are grouped into infrageneric...

Starch and Cellulose Starch

Cumarat Aus Cinnamat

Starch is the major reserve carbohydrate in plants. Potato, maize, cassava and wheat provide the main sources of energy in the human diet, but also serve for many industrial processes like adhesives, cosmetics, detergents, paper, textiles and pharmaceuticals Davis et al. 2003 . Starch is also used for the production of biodegradable plastics as an alternative to petroleum-based products. However, native starches from various plant species have limited physiochemical properties, and thus are...

Techniques Used to Detect a Transgenic Plant

To detect genetic modifications in plants in general for the methods of genetic modification, see Chaps. 1, 2 two different techniques could be applied Anklam et al. 2002 Holst-Jensen 2007 . One is based on the detection of genetic material DNA , for example by polymerase chain reaction PCR . This technique is most versatile for the detection of GM plants and therefore preferably used and chosen for many applications Lipp et al. 2005 . The alternative approach is detecting the newly expressed...

Strategies for the Multiplication of Male Sterile Lines

Although the described systems have provided important information about anther and pollen development, and ways to interfere with it, their potential use for commercial hybrid seed production is often limited because of the lack of Normal anther development male fertile plant Distorted anthers male sterile plant Fig. 14.3 Engineering male sterility with b-ketothiolase. a In chloroplasts, acetyl-CoA is normally converted by acetyl-CoA carboxylase to yield malonyl-CoA. b In transgenic plants...

Positive Selection Marker

There are sometimes different and confusing definitions in using the terms positive selection marker and negative selection marker. At present, positive selection systems are those that enable the growth of transformed cells, whereas negative selection systems kill the transformed cells see Sect. 3.3.4 . The most widely used selection marker systems are based on aminoglycoside-modifying enzymes. These amino glycoside-modifying enzymes confer resistances against antibiotics as kanamycin,...

Strategies for Metabolic Engineering in Plants

Metabolic engineers have access to a vast array of molecular and genetic tools to rewire plant metabolism, most of which aims at the modulation of enzyme activity either toward an increase or a decrease of metabolic flux through a given pathway. In the simplest case a single enzymatic step is the target for modulation. To increase the production of a desired compound or a novel compound, genes encoding biosynthetic enzymes of the pathway can be overexpressed. Further increases in flux can be...

Breeding Aims

Plant varieties must meet the requirements of plant production under special environmental and economical conditions. Moreover, the demands of food and feed industry as well as the consumers' preferences must be regarded. The yield potential is often the most important aim. Today's varieties are elites with high-yielding potential due to countless rounds of recombination and selection. Yield potential is a typical quantitative character controlled by many genes. Thus high yielding varieties...

Examples of the Intragenic Modification in Potato

Despite the importance of potato as the most frequently consumed vegetable, issues such as inbreeding depression, a high degree of heterozygosity, and poor fertility have hampered efforts to improve the yield and quality of this crop. Each year, millions of potato plants are evaluated in the United States for the basic input and storage traits required by the industry. The few clones selected through this rigorous process are subsequently processed and assayed for sensory traits associated with...

Requirements for the All Native DNA Transformation of Potato

An important aspect of the new approach to genetic modification is that it omits the use of bacterial selectable marker genes see also Chap. 3 . Initially developed procedures simply exclude a selection step, yielding potato transformation frequencies below 0.1 . These frequencies were increased to 2 by applying supervirulent Agrobacterium strains such as AGL0 de Vetten et al. 2003 . An alternative method was developed by employing two different transfer DNAs, one carrying a positive and...

Anti InsectNematode Genes Bt Toxins

Bt toxins have been known as molecules that are active against insects and nematodes since the beginning of the previous century. They are synthesized by the soil-borne gram-positive bacterium Bacillus thuringiensis Bt . About 400 Bt toxins are known so far produced by diverse B. thuringiensis strains Crickmore et al. 2009 . All of them have a crystal structure, therefore named Cry toxins. Because of the natural origin of the toxins, they occupy the position of the world's leading...

Types of Herbicide Resistance

Herbicide resistance has evolved in weeds in several general forms. The most common type of herbicide resistance in weeds is the modification of the herbicide target site Zelaya and Owen 2004 . Target site resistance can be either monogenic or polygenic the latter is often referred to as creeping resistance and may result from recurrent applications of low herbicide rates Gressel 1995 . In the case of monogenic herbicide resistance, typically resistance is accrued when there is a...

RNA Interference Based Gene Silencing

The principle of RNA interference RNAi consists of a naturally based degradation of dsRNA as a part of protection against pathogen attack, particularly virus infection. This mechanism was discovered in the nematode Caenorhabditis elegans, leading to gene silencing through the occurrence of double-stranded RNA dsRNA , mediating a downregulation of gene expression. Target RNA is degradated by enzyme complexes called DICER and RISC. The DICER endonucleases cuts double-stranded RNA into siRNAs of...

Protoplasts

Protoplasts are plant cells with their cell wall removed. Since the cell wall presents the most formidable barrier to the introduction of large molecules, removal of the cell wall increases the possibilities for DNA insertion. For cell wall removal, tissues are incubated with commercial mixes of cellulases and pectinases. During protoplast liberation, protoplasts are suspended in a salt solution containing sufficient amounts of osmotic stabilizers to prevent bursting Cocking 1972 . Protoplasts...

Whole Tissue Electroporation

To avoid the technical difficulties encountered with the manipulation of protoplasts, the introduction of DNA through electroporation of whole tissues has been explored. Attempts to electroporate DNA into completely untreated target tissues have not been reliable. Although seemingly positive results have occasionally been obtained, these have not been consistent. Whole-tissue electroporation is achievable following partial digestion or removal of cell wall material D'Halluin et al. 1992 using a...

Nanofiber Arrays

The use of nanofiber arrays for DNA introduction into plants is a relatively new approach for DNA introduction into plant cells and few reports of this method exist Finer and Dhillon 2008 . Nanofiber arrays are precisely arrayed thin fibers, which are grown directly on a silica chip Melechko et al. 2005 . When viewed using electron microscopy, these chips resemble a microscopic bed of nails. DNA is either precipitated onto, or chemically bound to the arrays and the chip is pressed to the target...

Detection of Stacked Events

A growing number of GM plant events containing stacked traits are approved and already cultivated in some countries Tavaniers et al. 2008 . Of the different approaches for the production of gene stacks, crossing GM events which express different traits e.g. by combining the Bt trait for insect resistance with a trait for herbicide tolerance is preferably applied to rapidly obtain stacked events for commercialisation. This type of stacked event is indeed widely accepted by breeders and forms...

Pineapple

Merr. follows banana, mango and citrus in terms of world tropical fruit production. In 2006 about 19 million t of pineapples were produced on approximately 950 000 ha worldwide http faostat.fao.org . Firoozabady et al. 2006 developed efficient methods for plant regeneration, via both organogenesis and embryogenesis, of Smooth Cayenne pineapple. Success has been reported in transforming pineapple by Agrobacterium-mediated gene delivery into friable embryogenic tissue...

Pollen Tube Pathway

In all fields of the sciences, premature claims are made which are often inadequately substantiated. The plant transformation sciences is certainly not exempt from this type of activity as new or more efficient methods for transformation are valuable and any success can accelerate career development. This rush to publish mentality has yielded numerous reports of new and exciting transformation methods which have not stood the test of time. The mixing of pollen with DNA and injecting DNA into...

Functional Map Of The Fruit-specific Promoter Of The Tomato 2a11 Gene.

Bajaj S, Ran Y, Phillips J, Kularajathevan G, Pal S, Cohen D, Elborough K, Puthigae S 2006 . A high throughput Agrobacterium tumefaciens-mediated transformation method for functional genomics of perennial ryegrass Lolium perenne L . Plant Cell Rep 25 651-659 Ballester A, Cervera M, Pena L 2007 Efficient production of transgenic citrus plants using isopentenyl transferase positive selection and removal of the marker gene by site-specific recombination. Plant Cell Rep 26 39-45 Bent AF 2006...

Part C Transgenic Plants in Breeding and Crop Production

15.1 Introduction 15.2 Importance and Potential Impact of Genetic Modification in 15.3 Transformation of Cotton and its Improvement via Genetic Modification 15.3.1 Methods Used to Transform Cotton 15.3.2 Selectable Markers and Reporter Genes used for Cotton Transformation 15.3.3 Genetically Engineered Traits in 15.3.4 The Role of New Technological Advances in Cotton Improvement 15.4 Future References 16 Triticeae Jochen Kumlehn, Grit Zimmermann, Carolin Berger, Cornelia Marthe, and Goetz Hensel...

Negative Selection Marker

Comparable with screenable marker genes, so-called negative selection markers are used to optimize transformation efficiency. Thereby negative selection systems kill the transformed cells. This allows new strategies to limit the production of vector-backbone-containing plants by flanking the T-DNA with negative selection marker genes. The most used negative selection marker gene is the codA gene from E. coli encoding cytosine deaminase. The usefulness of codA as a conditional toxic gene was...

The Role of New Technological Advances in Cotton Improvement

Successful transformation of the plastid genome in cotton has been achieved by Kumar et al. 2004 . Although chloroplast transformation is more difficult and less efficient compared to the nuclear transformation, it does offers some advantages, including transgene containment because of maternal inheritance of the trait and a high level of consistent transgene expression. Lower efficiency and the complexity of the plastid transformation system have prevented widespread adoption of this...

Natural Male Sterility Systems in Plants

In order to prevent the self-pollination of female lines, pollen fertility must be controlled to permit fertilization only by pollen from the male parent. A simple way to establish a female line for hybrid seed production is to identify or create a line that is unable to produce viable pollen, similar to some lines of maize Laughnan and Gabay-Laughnan 1983 or rice Kadowaki et al. 1988 . Therefore, this type of male-sterile line is unable to self-pollinate and seed formation is dependent upon...

Papaya

Papaya Carica papaya L. native to southern Mexico and Central America is an economically important fruit crop of tropical and subtropical regions. In 2006 about 7 million t of papaya were produced on approximately 370 000 ha worldwide http faostat.fao.org . However, most of the papaya plantations of the world suffer from the destructive disease caused by Papaya ringspot virus PRSV . Transformation in papaya is mainly based on an Agrobacterium tumefaciens-mediated method into callus, somatic and...

Conclusions and Future Perspectives

The use of hybrid crops has been a very important agricultural advance in recent years, because hybrids have an increased yield and a wider environmental adaptability and are more insect- and disease-resistant. One strategy that has been utilized for hybrid crop production is male sterility. Biotechnology has enabled new methods for obtaining male-sterile plants and developing several new Table 14.1 Commercially used male-sterile plants. Data are from AGBIOS GM database http www.agbios.com ....

Small Fruit

17.2.2.1 Fragaria Species Strawberry The genus Fragaria consists of approximately 20 species. The majority of these species are diploid. Commercially important is the octoploid species Fragaria x ananassa Duch. Hadonou et al. 2004 Sargeant et al. 2003 . In 2006 approximately 3.9 million of strawberry fruits were produced on 263 000 ha worldwide http faostat.fao.org . The cultivated strawberry F. x ananassa is a rapidly growing herbaceous perennial with a small genome, short reproductive cycle...

Drought Tolerant Perennial Ryegrass

Perennial ryegrass is one of the most important temperate pasture grasses and forms the biological foundation of the important meat, dairy, and wool export-based sectors of New Zealand. For this reason, a large genomics program based on the use of native genes and regulatory elements for the enhancement of ryegrass and white clover is funded by the New Zealand government and the pasture-based primary industries. The targets are i drought tolerance and extended geographical range and long-term...

Applications of RNAi for Crop Protection

As described in Sect. 5.2.1, one of the biological roles of RNA silencing is its participation in host defense processes, and inverted repeat-induced RNAi is now thought to act through the anti-viral defense pathway of RNA silencing Fusaro et al. 2006 . Many successful attempts to engineer virus resistance by transgenic approaches with virus-derived sequences, including at least some of the original coat protein expression experiments, are based on RNA silencing reviewed by Lindbo and Dougherty...

Pla M 2005 J Agric Food Chem 53 7003-7009

AGBIOS 2008 http www.agbios.com dbase.php. Accessed 23 Jan 2009 Ahn S, Costa J, Emanuel JR 1996 PicoGreen quantitation of DNA effective evaluation of samples pre- orpost-PCR. Nucleic Acids Res 13 2623-2625 Akiyama H, Watanabe T, Wakabayashi K, Nakade S, Yasui S, Sakata K, Chiba R, Spiegelhalter F, Hino A, Maitani T 2005 Quantitative detection system for corn sample containing combined-trait genetically modified corn. Anal Chem 77 7421-7428 Anklam E,Gadani F, Heinze P, Pijnenburg H, Van den Eede...

Breeding Methods

Today many crop plants can be easily transformed. However, transformation see Chaps. 1, 2 often depends on the genotype which requires further selection to introduce the transgene into an elite background. Transgenic elites can then be grown as a new variety or they can be used as parents to produce hybrid seeds. The different methods of breeding and selection are briefly explained in this chapter, together with specific requirements for transgenic plants and new alternatives offered by...

Persimmon

Japanese persimmon Diospyros kaki Thunb. native to East Asia is gaining popularity worldwide, especially as an out-of-season fruit for the northern hemisphere. In 2006 about 3.2 million t of persimmon were produced on approximately 730 000 ha worldwide http faostat.fao.org . An efficient plant regeneration system is available for persimmon shoot, callus and protoplast cultures see Tao and Dandekar 2000 . The first transgenic persimmon was reported by Tao et al. 1994 . Transformation in...

Engineering of Primary Metabolism Carbohydrate Metabolism

Starch Synthesis Pathway

The majority of metabolic fluxes inside a plant cell center on the formation and utilization of sugars, the primary products of photosynthesis and their conversion into storage and structural carbohydrates, such as starch and cellulose. Starch is the principle constituent of many of harvestable organs, such as tubers or grain. Besides its importance as a staple in human and animal diets, it is also used as a renewable raw material for a wide range of industrial applications Jobling 2004 ....

Screenable Marker Genes

Screenable markers encode a protein which is detectable because it produces a visible pigment or because it fluoresces or modifies the phenotype elsewhere under appropriate conditions. Screenable markers include galactosidase lacZ Herrera-Estrella et al. 1983 , ft-glucuronidase GusA Jefferson 1987 , luciferase luc Ow et al. 1986 , green fluorescent protein gfp Haseloff and Amos 1995 , red fluorescent protein rfp Campbell et al. 2002 and isopentenyl transferase ipt Ebinuma et al. 1997 ....

Applications of RNAi for Crop Improvement and Metabolic Engineering

In addition to crop protection, RNAi technology has been used successfully to modify agronomically relevant traits such as, e.g. nutritional or pharmaceutical value and crop toxicity reviewed by Tang et al. 2007 Hebert et al. 2008 . Many reports on the successful application of RNAi for crop improvement take advantage of the potential of RNAi to down-regulate multiple targets. For example, a nutritionally valuable high-lysine maize variant was produced by down-regulating the entire 22-kDa...

Preface

Today modern agriculture is facing new challenges. Total yields have to be increased due to the continuing population growth of mankind and due to changing food consumption. However, global climate creates new problems but also new opportunities for agriculture. For more than a decade the yearly yield increases of major food staples have been on the decline, which is due to optimized production systems like the application of mineral fertilizer and crop protection measures. But also the yield...

Chapter Triticeae Cereals

Jochen Kumlehn, Grit Zimmermann, Carolin Berger, Cornelia Marthe, and Goetz Hensel The Triticeae cereals include two of the most important crops worldwide - wheat Triticum aestivum, T. turgidum conv. durum and barley Hordeum vulgare -along with cereal rye Secale cereale and triticale xTriticosecale , both of which are relevant in certain agricultural environments. Together with maize Zea mays and rice Oryza sativa , wheat represents a major food crop, with gt 600x 106 t Mt global annual...

Delivery of Transforming DNA to the Chloroplast

Dna Chloroplast

Delivery of foreign DNA to the chloroplast requires its transport through several physical barriers the cell wall, the cytoplasma membrane, and the chloroplast double-membrane system. Since no bacterial or viral pathogen is known which could be utilized for DNA delivery, transgene transmission needs to employ rather rigid physical methods. The most effective and widely used system utilizes microprojectile bombardment with plasmid-coated gold or tungsten particles, the so-called biolistic...

Applications of RNA Interference in Transgenic Plants

Gene-silencing processes have been widely exploited as versatile experimental and biotechnological tools for functional gene studies and transgenic approaches to crop improvement, disease resistance, and metabolic engineering see Chap. 11 . These applications first and foremost rely on the trans-silencing capacity and the sequence specificity of RNA-mediated silencing mechanisms and are often collectively referred to as RNA interference RNAi techniques, in reference to the related RNA silencing...

Importance and Potential Impact of Genetic Modification in Cotton

Cotton plants are particularly susceptible to a wide variety of insect pests and nematodes, and their cultivation has traditionally relied on the use of large amounts of highly toxic pesticides. Some estimates suggest that, prior to the widespread adoption of Bt cotton, nearly 25 of all insecticides used worldwide were needed for the production of cotton Pannetier et al. 1997 . Genetically modified cotton produced by incorporating the Bt gene was therefore a huge success in the United States...

Transient Expression Systems

Transient expression systems do not involve transgenic plants or cells - the transgene encoding the pharmaceutical protein remains episomal rather than integrating into the host genome. Such systems are based either on the transient expression of episomal DNA following standard transformation Agrobacterium or direct transfer by particle bombardment, see Chap. 1 or on the use of plant viruses as vectors. Although transient expression following standard transformation is mostly used as a rapid...

Vector Design Flanking Regions

Petunia Plastome

Agrobacterium-mediated transformation utilizes universal vector systems Lee and Gelvin 2008 see also Chapter 1 in which the transgene expression cassette is flanked by two rather short sequence stretches, termed left border LB and right border RB . These sequences facilitate almost random insertion of the transgene cassette into the host genome, resulting in multiple individual lines differing in site and numbers of transgene integration. In absolutely contrast, insertion of foreign DNA into...

Contributors

Fredy Altpeter Agronomy Department, Plant Molecular Biology Program, Genetics Institute and University of Florida-IFAS, Gainesville, FL 32611, USA, altpeter ufl.edu Dorothea Bartels Institute of Molecular Biology and Biotechnology of Plants IMBIO , University of Bonn, Kirschallee 1, Bonn 53115, Germany, dbartels uni-bonn.de Detlef Bartsch Bundesamt fur Verbraucherschutz und Lebensmittelsicherheit BVL , Mauerstra e 39-41, Berlin 10117, Germany, Detlef.Bartsch bvl.bund.de Joachim Bendiek...

Screening

Gmo Testing

For the expression of newly integrated genes, GM plant developers use a limited number of regulatory elements promoters and terminators . Since these elements Fig. 7.2 Procedure for GMO testing of food, feed and seeds from a European perspective. A stepwise approach consisting of GMO screening, identification and quantification is commonly applied for testing food, feed and seed products for compliance with European authorisation and labelling regulations Fig. 7.2 Procedure for GMO testing of...

Canola

Genetically modified herbicide-resistant canola was introduced commercially in Canada in 1995 and approximately 80 of the herbicide-resistant canola is transgenic, primarily to glyphosate, which is much higher than the global percentage ca. 20 James 2008 . Transgenic glyphosate-resistant canola contains the transgene that code for the mutant cp4 epsps but also has a transgene that codes for glyphosate oxidoreductase GOX Duke 2005 . The other transgenic herbicide-resistant canola is resistant to...

Metabolic Engineering of Lipid Metabolism

Glycerol Phosphate Pathway Dgat

A plant cell contains a plethora of lipid species, which are mainly represented by free fatty acids, glycolipids, phospholipids, waxes and neutral glycerolipids. Vegetable oil for human consumption almost exclusively consists of triacylglycerols TAGs , which are composed of three fatty acids esterified to glycerol. TAGs dominate the storage lipid pool in oilseeds from which most plant oils are isolated. There are five fatty acids that are commonly esterified to triglycerides in the predominant...

Genetic Variation in Plant Breeding

Breeding with transgenic plants is only justified when genetic variation within the primary and secondary gene pools of a species is too small or gene transfer by conventional techniques is difficult and time-consuming. There are a number of different means for increasing or even creating new genetic variation, like species hybridization, mutation induction and protoplast fusion, which have been frequently used to breed new varieties Fig. 6.1 . It is worth mentioning that neither plant...

DNABased Detection

DNA-based detection of transgenic plants targets the novel DNA sequences introduced into the crop genome. These methods show the absence or presence of GM plant material in a sample and can also measure the relative quantity percentage in a tested sample. Fig. 7.1 Analytical strategy and targeted sequences. Detection of genetically modified plants in food, feed and seed samples is generally conducted by consecutive PCR tests targeting the genetic elements element-specific and constructs...