scholarly journals Genetic Transformation Methods for Crop Improvement- A Brief Review

2019 ◽  
Vol 40 (04) ◽  
Author(s):  
C Kavipriya ◽  
A Yuvaraja ◽  
K Senthil ◽  
C Menaka
Keyword(s):  
Gene Transfer ◽  
Genetic Engineering ◽  
Indirect Method ◽  
Crop Improvement ◽  
Plant Cells ◽  
Transformation Method ◽  
Gene Gun ◽  
Steady Growth ◽  
Transfer Genes ◽  
Transformation Methods

Decades of documented successful pieces of evidence in agritech have shown us a clear picture of the importance of biotechnology in crop improvement. The production in agriculture should have steady growth and to achieve these objective conventional methods should go on parallel with biotechnological approaches. Genetic engineering which has revolutionized the path of crop improvement involves the identification and transfer of novel genes into the existing elite cultivars. Different methods of transferring the gene into plant cells have been developed and continuous efforts have been made to increase its efficiency. Both direct and indirect method of gene transfer has its own merits and demerits. Efforts have been made continuously to eliminate drawbacks and to develop an easy, elite and eco-friendly method to transfer genes. The transformation method which is a base of genetic engineering is vital and Agrobacterium-mediated gene transfer and gene gun have shown to be doing well in recent years. As a whole the methodology involved, merits and demerits of different methods have been briefly discussed.

The production and uses of genetically transformed plants: concluding remarks

1993 ◽  
Vol 342 (1301) ◽  
pp. 293-294
Keyword(s):  
Gene Transfer ◽  
Crop Improvement ◽  
Plant Biotechnology ◽  
Cell Types ◽  
Crop Plants ◽  
Transformed Plants ◽  
The Past ◽  
New Approaches ◽  
Transfer Genes ◽  
Biological Methods

This meeting at which the preceding collection of papers were presented occurred on the tenth anniversary of the development of techniques which have laid the foundation for modern plant biotechnology, namely the ability to transfer genes into plants and to direct their expression in appropriate cell types. The contributors have revealed many of the exciting and potentially important applications of gene transfer technology in crop plants arising from these earlier developments, and have also described new approaches which have engendered an ever-widening scope for crop improvement through the application of molecular biological methods. In the past ten years a wide variety of crop plants have been stably transformed, and it is clear that many of the major crops can now be transformed, although with widely different efficiencies.

scholarly journals A new method for identifying the role of marital preferences at shaping marriage patterns

2021 ◽  
pp. 1-27
Author(s):  
Anna Naszodi ◽  
Francisco Mendonca
Keyword(s):  
Contingency Table ◽  
Transformation Method ◽  
New Method ◽  
Marriage Patterns ◽  
The Us ◽  
Analytical Properties ◽  
The Matrix ◽  
Transformation Methods

Abstract We develop a method which assumes that marital preferences are characterized either by the scalar-valued measure proposed by Liu and Lu, or by the matrix-valued generalized Liu–Lu measure. The new method transforms an observed contingency table into a counterfactual table while preserving its (generalized) Liu–Lu value. After exploring some analytical properties of the new method, we illustrate its application by decomposing changes in the prevalence of homogamy in the US between 1980 and 2010. We perform this decomposition with two alternative transformation methods as well where both methods capture preferences differently from Liu and Lu. Finally, we use survey evidence to support our claim that out of the three considered methods, the new transformation method is the most suitable for identifying the role of marital preferences at shaping marriage patterns. These data are also in favor of measuring assortativity in preferences à la Liu and Lu.

scholarly journals Random numbers from the tails of probability distributions using the transformation method

2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Daniel Fulger ◽  
Enrico Scalas ◽  
Guido Germano
Keyword(s):  
Probability Distributions ◽  
Transformation Method ◽  
Fractional Diffusion ◽  
Random Numbers ◽  
Stochastic Solution ◽  
Probability Densities ◽  
Speed Up ◽  
Time Fractional Diffusion Equation ◽  
Transformation Methods ◽  
Very High

AbstractThe speed of many one-line transformation methods for the production of, for example, Lévy alpha-stable random numbers, which generalize Gaussian ones, and Mittag-Leffler random numbers, which generalize exponential ones, is very high and satisfactory for most purposes. However, fast rejection techniques like the ziggurat by Marsaglia and Tsang promise a significant speed-up for the class of decreasing probability densities, if it is possible to complement them with a method that samples the tails of the infinite support. This requires the fast generation of random numbers greater or smaller than a certain value. We present a method to achieve this, and also to generate random numbers within any arbitrary interval. We demonstrate the method showing the properties of the transformation maps of the above mentioned distributions as examples of stable and geometric stable random numbers used for the stochastic solution of the space-time fractional diffusion equation.

scholarly journals Genetic Transformation of Apomictic Grasses: Progress and Constraints

2021 ◽  
Vol 12 ◽  
Author(s):  
Andrés M. Bellido ◽  
Eduado D. Souza Canadá ◽  
Hugo R. Permingeat ◽  
Viviana Echenique
Keyword(s):  
Genetic Transformation ◽  
Plant Transformation ◽  
Large Scale ◽  
Crop Improvement ◽  
Current Status ◽  
Grass Species ◽  
Brachiaria Brizantha ◽  
Apomictic Species ◽  
Transformation Methods

The available methods for plant transformation and expansion beyond its limits remain especially critical for crop improvement. For grass species, this is even more critical, mainly due to drawbacks in in vitro regeneration. Despite the existence of many protocols in grasses to achieve genetic transformation through Agrobacterium or biolistic gene delivery, their efficiencies are genotype-dependent and still very low due to the recalcitrance of these species to in vitro regeneration. Many plant transformation facilities for cereals and other important crops may be found around the world in universities and enterprises, but this is not the case for apomictic species, many of which are C4 grasses. Moreover, apomixis (asexual reproduction by seeds) represents an additional constraint for breeding. However, the transformation of an apomictic clone is an attractive strategy, as the transgene is immediately fixed in a highly adapted genetic background, capable of large-scale clonal propagation. With the exception of some species like Brachiaria brizantha which is planted in approximately 100 M ha in Brazil, apomixis is almost non-present in economically important crops. However, as it is sometimes present in their wild relatives, the main goal is to transfer this trait to crops to fix heterosis. Until now this has been a difficult task, mainly because many aspects of apomixis are unknown. Over the last few years, many candidate genes have been identified and attempts have been made to characterize them functionally in Arabidopsis and rice. However, functional analysis in true apomictic species lags far behind, mainly due to the complexity of its genomes, of the trait itself, and the lack of efficient genetic transformation protocols. In this study, we review the current status of the in vitro culture and genetic transformation methods focusing on apomictic grasses, and the prospects for the application of new tools assayed in other related species, with two aims: to pave the way for discovering the molecular pathways involved in apomixis and to develop new capacities for breeding purposes because many of these grasses are important forage or biofuel resources.

scholarly journals Melatonin and Carbohydrate Metabolism in Plant Cells

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1917
Author(s):  
Marino B. Arnao ◽  
Josefa Hernández-Ruiz ◽  
Antonio Cano ◽  
Russel J. Reiter
Keyword(s):  
Crop Improvement ◽  
Plant Cells ◽  
Primary Metabolism ◽  
Degradation Pathways ◽  
Biotic And Abiotic Stress ◽  
Relevant Role ◽  
Tolerance Response ◽  
Simple Carbohydrates ◽  
Living Organisms

Melatonin, a multifunctional molecule that is present in all living organisms studied, is synthesized in plant cells in several intercellular organelles including in the chloroplasts and in mitochondria. In plants, melatonin has a relevant role as a modulatory agent which improves their tolerance response to biotic and abiotic stress. The role of melatonin in stress conditions on the primary metabolism of plant carbohydrates is reviewed in the present work. Thus, the modulatory actions of melatonin on the various biosynthetic and degradation pathways involving simple carbohydrates (mono- and disaccharides), polymers (starch), and derivatives (polyalcohols) in plants are evaluated. The possible applications of the use of melatonin in crop improvement and postharvest products are examined.

EMBRYO MANIPULATION AND GENE TRANSFER IN LIVESTOCK

1985 ◽  
Vol 65 (3) ◽  
pp. 527-538 ◽  
Author(s):  
R. B. CHURCH ◽  
F. J. SCHAUFELE ◽  
K. MECKLING
Keyword(s):  
Gene Transfer ◽  
Genetic Engineering ◽  
Embryo Transfer ◽  
Dna Sequences ◽  
Recombinant Dna ◽  
Fusion Gene ◽  
Bovine Genome ◽  
Monozygotic Twins ◽  
Genetically Engineered ◽  
Livestock Species

In the past few years significant progress has been made in manipulation of reproduction and in development of genetic engineering techniques which can be applied to animal species. Artificial insemination and embryo transfer are now used widely in the livestock industry. The advent of non-surgical embryo collection and transfer, embryo freezing and splitting along with estrus synchronization has allowed the industry to move from the laboratory to the farm. Embryo manipulation now involves embryo splitting to produce monozygotic twins, in vitro fertilization, cross-species fertilization, embryo sexing, and chimeric production of tetraparental animals among others. Advances in recombinant DNA, plasmid construction and embryo manipulation technologies allow the production of genetically engineered animals. The application of recombinant DNA technology involves the isolation and manipulation of desired genes which have potential for significant changes in productivity in genetically engineered livestock. Recombinant DNA constructs involve the coupling of promoter, enhancer, regulatory and structural DNA sequences to form a "fusion gene" which can then be multiplied, purified, assayed and expressed in cell culture prior to being introduced into an animal genome. Such DNA gene constructs are readily available for many human and mouse genes. However, they are not readily available for livestock species because the detailed molecular biology has not yet been established in these species. Gene transfer offers a powerful new tool in animal research. Transfer of genes into the bovine genome has been accomplished. However, successful directed expression of these incorporated genes has not been achieved to date. New combinations of fusion genes may be an effective way of producing transgenic domestic animals which show controlled expression of the desired genes. Embryo manipulation and genetic engineering in livestock species is moving rapidly. The problems being addressed at present in numerous laboratories will result in enhanced livestock production in the not too distant future. Key words: Embryo transfer, embryo manipulation, transgenic livestock, genetic engineering, gene transfer, monozygotic twins

Genetic engineering of virus resistance: a successful genetical alchemy

1992 ◽  
Vol 99 (3-4) ◽  
pp. 61-77
Author(s):  
B. D. Harrison
Keyword(s):  
Genetic Engineering ◽  
Resistance Genes ◽  
Virus Resistance ◽  
Crop Improvement ◽  
Genetically Engineered ◽  
Satellite Rna ◽  
Virus Diseases ◽  
Naturally Occurring ◽  
Resistance To Infection ◽  
Specific Tolerance

SynopsisSome of the most successful early applications of genetic engineering in crop improvement have been in the production of virus-resistant plants. This has been achieved not by the transfer of naturally occurring resistance genes from one plant species or variety to another but by transformation with novel resistance genes based on nucleotide sequences derived from the viruses themselves or from virus-associated nucleic acids. Transformation of plants with a DNA copy of the particle protein gene of viruses that have positive-sense single-stranded RNA genomes typically confers resistance to infection with the homologous and closely related viruses. Transformation with a gene that is transcribed to produce a benign viral satellite RNA can confer virus-specific tolerance of infection. In addition, recent work with viral poly-merase gene-related sequences offers much promise, and research is active on other strategies such as the use of virus-specific ribozymes.Already the field trialling of plants incorporating transgenic virus resistance has begun, with encouraging results, and effects on virus spread are being studied. Deployment strategies for the resistant plants must now be devised and the conjectural hazards of growing them assessed. Genetically engineered virus resistance promises to make a major contribution to the control of plant virus diseases by non-chemical methods.

Genes transferred by retroviral vectors into normal and mutant myoblasts in primary cultures are expressed in myotubes

1990 ◽  
Vol 10 (6) ◽  
pp. 3268-3271
Author(s):  
B F Smith ◽  
R K Hoffman ◽  
U Giger ◽  
J H Wolfe
Keyword(s):  
Gene Transfer ◽  
Primary Cultures ◽  
Muscle Cells ◽  
Retroviral Vectors ◽  
Retroviral Vector ◽  
Enzyme Deficiency ◽  
Transfer Genes

Retroviral vectors were used to transfer genes efficiently into rat and dog myoblasts in primary cultures under conditions which permitted the transduced myoblasts to differentiate into myotubes expressing the transferred genes. The transduced myotubes expressed normal markers of differentiation and were morphologically indistinguishable from uninfected myotubes. Retroviral vector-mediated gene transfer was also used to correct a genetic enzyme deficiency in mutant canine muscle cells.

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