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 Gdd
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,...
Introduction Idt
The agricultural exploitation of hybrid crop varieties has enabled enormous increases in food productivity through increased uniformity and hybrid vigour. Because of hybrid vigour, or heterosis, these crops are characterized by an increased resistance to disease and enhanced performance in different environments when comparing the heterozygous hybrid progeny called F1 hybrids to the homozygous parents Lefort-Buson et al. 1987 . Heterotic hybrid varieties in major crops, such as cotton, maize,...
Top Fruit
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
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 MaleSterile 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 AllNative 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...
AntiInsectNematode 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 InterferenceBased 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...
Introduction Ndz
An apple a day keeps the doctor away is a popular adage which shows the importance of fruit crops for the human diet. It is a matter of common knowledge that a diet rich in fruits and vegetables and low in saturated fats is healthy and protective against cardiovascular diseases and certain cancers Block et al. 1992 Ferro-Luzzi et al. 1994 Morris et al. 1994 . The World Health Organization 1990 WHO therefore recommends a daily intake of more than 400 g of vegetables and fruits per person. The...
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...
References Dpu
ACNFP 1996 The use of antibiotic resistance markers in genetically modified plants for human food. The Advisory Committee on Novel Foods and Processes, London AGBIOS 2008 http www.agbios.com dbase.php. Agriculture amp Biotechnology Strategies Canada Arias RS, Dayan FE, Michel A, Howell JL, Scheffler BE 2006 Characterization of a higher plant herbicide-resistant phytoene desaturase and its use as a selectable marker. Plant Biotechnol J 4 263-273 Arumugam N, Gupta V, Jagannath A, Mukhopadhyay 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
Pineapple Ananas comosus L. 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...
Introduction Jsn
Quality traits, including alterations in metabolite composition of crop plants, have been major targets of traditional breeding programs. One of the most prominent examples is the introduction of rape seed varieties low in erucid acid in seed oil and in glucosinolates in meal approximately 30 years ago which was an important step towards improving the nutritional properties of rape seed products. However, conventional breeding strategies depend on the availability of significant genetic...
References Jkf
Bacheler J, Mott D, Bowman DT 2006 The relative efficacy of Bollgard, Bollgard II and WideStrike lines against bollworms in North Carolina in 2003 and 2005 implications for producer choices. Proc Beltwide Cotton Conf 2006 1536-1540 Baum JA, Bogaert T, Clinton W, Heck GR, Feldmann P, Ilagan O, Johnson S, Plaetinck G, Munyikwa T, Pleau M, Vaughn T, Roberts J 2007 Control of coleopteran insect pests through RNA interference. Nat Biotechnol 25 1322-1326 Bayley C, Trolinder N, Ray C, Morgan M,...
A 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...
References Pcy
Atkinson HJ, Urwin PE, McPherson MJ 2003 Engineering plants for nematode resistance. Annu Rev Phytopathol 41 615-639 Aylife MA, Lagudah ES 2004 Molecular genetics of disease resistance in cereals. Ann Bot 94 765-773 Bakker E, Achenbach U, Bakker J, van Vliet J, Peleman J, Segers B, van der Heijden S, van der Linde P, Graveland R, Hutten R 2004 A high-resolution map of the H1 locus harbouring resistance to the potato cyst nematode Globodera rostochiensis. Theor Appl Genet 109 146-152 Bates SL,...
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...
Introduction
The genome of eukaryotic cells is unevenly distributed and kept in different subcellular compartments. While the vast majority of genetic information is sheltered in the nucleus, small portions of DNA reside in organelles, namely the mitochondria and - in the case of plants - in the plastids. These unique organelles which in their most prominent manifestation are called chloroplasts, developed from cyanobacterial ancestors in a process described by the well accepted endo-symbiosis theory Gould...
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...
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 ....
References Akx
Akagi H, et al 2004 Positional cloning of the rice Rf-1 gene, a restorer of BT-type cytoplasmic male sterility that encodes a mitochondria-targeting PPR protein. Theor Appl Genet 108 1449-1457 Basra AS ed 2000 Hybrid seed production in vegetables rationale and methods in selected crops. Food Products, Binghamton, N.Y. Bino RJ 1985 Histological aspects of microsporogenesis in fertile, cytoplasmic male-sterile and restored fertile Petunia hybrida. Theor Appl Genet 69 423-428 Brown GG, et al 2003...
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...
DroughtTolerant 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...
References Hvf
Abranches R, Shultz RW, Thompson WF, Allen GC 2005 Matrix attachment regions and regulated transcription increase and stabilize transgene expression. Plant Biotechnol J 3 535-543 Altpeter F, Baisakh N, Beachy R, Bock R, Capell T, Christou P, Daniell H, Datta K, Datta S, Dix PJ, Fauquet C, Huang N, Kohli A, Mooibroek H, Nicholson L, Nguyen TT, Nugent G, Raemakers K, Romano A, Somers DA, Stoger E, Taylor N, Visser R 2005 Particle bombardment and the genetic enhancement of crops myths and...
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...
Introduction 1
Historically, plant breeding has been based on trial and error. While environmental factors originally determined selection, pre-agricultural men eventually developed a more purposeful extension of this process. This meant that selection was mainly based on appearance, yield, vigorous growth, taste and smell. Especially the past century resulted in new breeding programs that led to exceptional increases in both the quality and quantity of crops. In recent years genetic transformation techniques...
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...
References Pcp
Abebe T, Guenzi AC, Martin B, Cushman JC 2003 Tolerance of mannitol-accumulating transgenic wheat to water stress and salinity. Plant Physiol 131 1748-1755 Alfonso J, Ortego F, Sanchez-Monge R, Garcia-Casado G, Pujol I, Castanera P, Salcedo G 1997 Wheat and barley inhibitors active towards a-amylase and trypsin-like activities from Spodoptera frugiperda. J Chem Ecol 23 1729-1741 Altpeter F, Vasil V, Srivastava V, Vasil IK 1996 Integration and expression of the high- molecular-weight glutenin...
Engineering of Primary Metabolism Carbohydrate Metabolism
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...
