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1.
Recent advances in wheat transformation 总被引:9,自引:0,他引:9
Vasant janakiraman Martin Steinau Serena B. McCoy Harold N. Trick 《In vitro cellular & developmental biology. Plant》2002,38(5):404-414
Summary Since the first report of wheat transformation in the early 1990s, genetic engineering of wheat has evolved rapidly. Several
laboratories worldwide have reported the production of fertile transgenic wheat plants using a variety of methods. While there
are several innovative and promising approaches for wheat transformation using different explants as targets for transformation,
different methods of transformation, and different selection schemes, the most common approach to wheat transformation is
the bombardment of tissue derived from immature embryos followed by selection based on resistance to the bar gene. Even with all these successful reports, hurdles still exist for this recalcitrant crop. Of these hurdles, low transformation
rates, tools for transgene expression, and transgene silencing in subsequent generations are probably the most critical. This
review will provide an overview of wheat transformation in the past decade, addressing both positive and negative factors
that effect transformation while highlighting the successes of the past and prospects for the future. 相似文献
2.
Summary Transfer of genes from heterologous species provides the means of selectively introducing new traits into crop plants and
expanding the gene pool beyond what has been available to traditional breeding systems. With the recent advances in genetic
engineering of plants, it is now feasible to introduce into crop plants, genes that have previously been inaccessible to the
conventional plant breeder, or which did not exist in the crop of interest. This holds a tremendous potential for the genetic
enhancement of important food crops. However, the availability of efficient transformation methods to introduce foreign DNA
can be a substantial barrier to the application of recombinant DNA methods in some crop plants. Despite significant advances
over the past decades, development of efficient transformation methods can take many years of painstaking research. The major
components for the development of transgenic plants include the development of reliable tissue culture regeneration systems,
preparation of gene constructs and efficient transformation techniques for the introduction of genes into the crop plants,
recovery and multiplication of transgenic plants, molecular and genetic characterization of transgenic plants for stable and
efficient gene expression, transfer of genes to elite cultivars by conventional breeding methods if required, and the evaluation
of transgenic plants for their effectiveness in alleviating the biotic and abiotic stresses without being an environmental
biohazard. Amongst these, protocols for the introduction of genes, including the efficient regeneration of shoots in tissue
cultures, and transformation methods can be major bottlenecks to the application of genetic transformation technology. Some
of the key constraints in transformation procedures and possible solutions for safe development and deployment of transgenic
plants for crop improvement are discussed. 相似文献
3.
Repellin Anne Båga Monica Jauhar Prem P. Chibbar Ravindra N. 《Plant Cell, Tissue and Organ Culture》2001,64(2-3):159-183
Genetic improvement of crops has traditionally been achieved through sexual hybridization between related species, which has resulted in numerous cultivars with high yields and superior agronomic performance. Conventional plant breeding, sometimes combined with classical cytogenetic techniques, continues to be the main method of cereal crop improvement. More recently, through the introduction of new tools of biotechnology, crossing barriers have been overcome, and genes from unrelated sources have become available to be introduced asexually into plants. Cereal crops were initially difficult to genetically engineer, mainly due to their recalcitrance to in vitro regeneration and their resistance to Agrobacterium infection. Systematic screening of cultivars and explant tissues for regeneration potential, development of various DNA delivery methods and optimization of gene expression cassettes have produced transformation protocols for the major cereals, although some elite cultivars still remain recalcitrant to transformation. Most of the transgenic cereals developed for commercial purpose exhibit herbicide and/or insect resistance; traits that are often controlled by a single gene. In recent years, more complex traits, such as dough functionality in wheat and nutritional quality of rice have been improved by the use of biotechnology. The current challenges for genetic engineering of plants will be to understand and control factors causing transgene silencing, instability and rearrangement, which are often seen in transgenic plants and highly undesirable in lines to be used for crop development. Further improvement of current cereal cultivars is expected to benefit greatly from information emerging from the areas of genomics, proteomics and bioinformatics. 相似文献
4.
Varshney Alok Altpeter Fredy 《Molecular breeding : new strategies in plant improvement》2002,8(4):295-309
In order to efficiently complement traditional wheat breeding with genetic transformation technology it will be desirable to introduce transgenes into the ideal genetic background. Poor tissue culture performance is limiting the number of wheat genotypes that can be stably transformed. We statistically analysed the tissue culture response of 38 current European winter wheats and discuss genetic factors influencing this trait. Although regenerable callus cultures could be initiated from immature embryos of all 38 winter wheats analysed, the number of regenerated plants per cultured explant differed highly significantly (p<0.01) among genotypes. Ten cultivars with excellent ranking in this parameter were selected for transformation experiments. Independent transgenic plants were recovered from nine winter wheat genotypes with a frequency ranging between 0.2% and 2.0% of the cultured immature embryos after biolistic transfer of the bar gene and bialaphos selection. The nine transformable winter wheat genotypes included a recently released high-yielding, disease-resistant cultivar (cv. Certo), well established cultivars with elite bread-making quality (cv. Tarso, Alidos) and current breeding lines differing in yield, disease resistance and grain quality. Transgene integration and expression were confirmed by Southern blot analysis, polymerase chain reaction, phosphinothricin acetyltransferase activity assay and herbicide application. Transgene expression was stably transmitted to the sexual progeny of all transgenic lines analysed and segregated in a Mendelian fashion in the majority of lines. The introduction of transgenes into the ideal genetic background will allow a thorough evaluation of their crop improvement potential. 相似文献
5.
The trait for somatic embryogenesis is being introduced sexually into alfalfa (Medicago sativa) breeding populations to facilitate genetic transformation of this crop. Cocultivation experiments were conducted with an agronomically-improved embryogenic clone from one such population as well as with two other embryogenic clones, one of which was the source of the embryogenic trait in the breeding populations. Transgenic plants were produced from the agronomically-improved clone whereas none were produced from the other two clones. Among the 16 transgenic plants analyzed there was a range in both copy number and number of integration sites for the NPT-II gene; those plants regenerated after a prolonged selection phase in vitro generally had the highest numbers in both respects. There was no evidence of sectoral chimerism of the transgene in a subsample of transgenic plants analyzed by PCR. 相似文献
6.
Age-dependent transformation frequency in elite wheat varieties. 总被引:10,自引:0,他引:10
G M Pastori M D Wilkinson S H Steele C A Sparks H D Jones M A Parry 《Journal of experimental botany》2001,52(357):857-863
Wheat is a major world crop and as such is a primary target for improvement of agronomic characteristics via genetic engineering. Optimization of transformation is essential in order to overcome the relatively low transformation frequencies encountered with wheat. Transformation of elite wheat varieties is not always successful due to variability in regeneration and transformation frequencies between varieties. In this work, two elite wheat varieties with a relatively high embryogenic capacity were transformed by particle bombardment. A strong correlation between transformation frequency and the age of wheat donor plants was observed in both varieties. The mean transformation frequency rose from 0.7% to 5% when using immature embryos from old and young donor plants, respectively. This was observed in both varieties, the best bombardments achieving up to 7.3% frequency. Using explants at an optimal developmental stage from donor plants grown under environmentally-controlled conditions has improved the reproducibility of transformation efficiency of elite wheat varieties and leads to the production of apparently phenotypically normal, fertile, transgenic plants. 相似文献
7.
Nakano A Suzuki G Yamamoto M Turnbull K Rahman S Mukai Y 《Molecular genetics and genomics : MGG》2005,273(2):123-129
Introduction of large-DNA fragments into cereals by Agrobacterium-mediated transformation is a useful technique for map-based cloning and molecular breeding. However, little is known about the organization and stability of large fragments of foreign DNA introduced into plant genomes. In this study, we produced transgenic rice plants by Agrobacterium-mediated transformation with a large-insert T-DNA containing a 92-kb region of the wheat genome. The structures of the T-DNA in four independent transgenic lines were visualized by fluorescence in situ hybridization on extended DNA fibers (fiber FISH). By using this cytogenetic technique, we showed that rearrangements of the large-insert T-DNA, involving duplication, deletion and insertion, had occurred in all four lines. Deletion of long stretches of the large-insert DNA was also observed in Agrobacterium. 相似文献
8.
Fernando Pistón Carmen García Gloria de la Viña José Pío Beltran Luis A. Cañas Francisco Barro 《Molecular breeding : new strategies in plant improvement》2008,21(3):401-405
Many plant genetic engineering applications require spatial expression of genes which in turn depends upon the availability
of specific promoters. In cereals, genetic modification of flowering and grain setting to influence yield and grain quality
is of significant interest. PsEND1 is a pea promoter that displays expression in the epidermis, connective tissue, endothecium and middle layers during different
stages of anther development. No homeologous sequence of this promoter or its coding sequence has been found in cereals. This
present work aimed at the characterization of the pea PsEND1 promoter driving the expression of the gusA gene in transgenic wheat. Nine transgenic lines were produced by particle bombardment and analyzed for the expression of
the gusA gene throughout development by histochemical GUS staining and by RT-PCR in vegetative and reproductive tissues and organs.
Expression of the gusA gene was first detected during pollen development, in microspores at binucleate stage. Activity of the gusA gene was also found in mature pollen, after anthesis. Following pollen grain germination, expression of the gusA gene was seen from an early stage of pollen tube formation until advanced stages, approaching the ovary. No further expression
of the gusA gene was detected after fertilization, nor during seed development. The results reported here show that the PsEND1 promoter is functional in wheat and its patterns of expression may be of interest for the application of genetic modification
in wheat breeding. 相似文献
9.
《Critical reviews in biotechnology》2013,33(4):287-314
AbstractCereals are the most important group of plants for human nutrition and animal feed. Partially due to the commercial value of crop plants, there has been an ever-increasing interest in using modern biotechnological methods for the improvement of the characteristics of cereals during the past decade. The rapid progress in molecular biology, plant cell culture techniques, and gene transfer technology has resulted in successful transformations of all the major cereals—maize, rice, wheat, and barley. This brings the biotechnological methods closer to the routine also in barley breeding. In this article, the current status of barley genetic engineering, including the patent situation, is reviewed. The needs, aims, and possible applications of genetic engineering in barley breeding are discussed. 相似文献
10.
Fredy Altpeter Vimla Vasil Vibha Srivastava Eva Stöger Indra K. Vasil 《Plant cell reports》1996,16(1-2):12-17
We have developed a method for the accelerated production of fertile transgenic wheat (Triticum aestivum L.) that yields rooted plants ready for transfer to soil in 8–9 weeks (56–66 days) after the initiation of cultures. This was made possible by improvements in the procedures used for culture, bombardment, and selection. Cultured immature embryos were given a 4–6 h pre-and 16 h post-bombardment osmotic treatment. The most consistent and satisfactory results were obtained with 30 g of gold particles/bombardment. No clear correlation was found between the frequencies of transient expression and stable transformation. The highest rates of regeneration and transformation were obtained when callus formation after bombardment was limited to two weeks in the dark, with or without selection, followed by selection during regeneration under light. Selection with bialaphos, and not phosphinothricin, yielded more vigorously growing transformed plantlets. The elongation of dark green plantlets in the presence of 4–5 mg/l bialaphos was found to be reliable for identifying transformed plants. Eighty independent transgenic wheat lines were produced in this study. Under optimum conditions, 32 transformed wheat plants were obtained from 2100 immature embryos in 56–66 days, making it possible to obtain R3 homozygous plants in less than a year. 相似文献
11.
Production of transgenic maize plants and progeny by bombardment of hi-II immature embryos 总被引:4,自引:0,他引:4
D. D. Songstad C. L. Armstrong W. L. Petersen B. Hairston M. A. W. Hinchee 《In vitro cellular & developmental biology. Plant》1996,32(3):179-183
Summary Production of transgenic maize (Zea mays L.) callus, plants, and progeny from microprojectile bombardment of 2–5-d cultured Hi-II immature embryos is described. Histological
evidence indicates that these tissues are amenable to transformation due to surface layer cell division of the scutellum.
Two out of every 100 bombarded embryos produced transgenic callus and R0 transgenic plants were both male and female fertile. Expected segregation of transgenes was observed in progeny. The primary
advantage of bombarding these tissues is increased male and female fertility of transgenic plants compared with those produced
using long-term callus or suspension cultures. 相似文献
12.
Abdul Qayyum Rao Allah Bakhsh Sarfraz Kiani Kamran Shahzad Ahmad Ali Shahid Tayyab Husnain S. Riazuddin 《Biotechnology advances》2009,27(6):753
Technology development is innovative to many aspects of basic and applied plant transgenic science. Plant genetic engineering has opened new avenues to modify crops, and provided new solutions to solve specific needs. Development of procedures in cell biology to regenerate plants from single cells or organized tissue, and the discovery of novel techniques to transfer genes to plant cells provided the prerequisite for the practical use of genetic engineering in crop modification and improvement. Plant transformation technology has become an adaptable platform for cultivar improvement as well as for studying gene function in plants. This success represents the climax of years of efforts in tissue culture improvement, in transformation techniques and in genetic engineering. Plant transformation vectors and methodologies have been improved to increase the efficiency of transformation and to achieve stable expression of transgenes in plants. This review provides a comprehensive discussion of important issues related to plant transformation as well as advances made in transformation techniques during three decades. 相似文献
13.
Advances in cereal protoplast research 总被引:5,自引:0,他引:5
Beginning in 1986, plants have been regenerated from protoplasts of all of the important cereal species, including wheat, rice, maize, and barley, and grasses such as sugarcane. In addition, somatic hybrids/cybrids as well as transgenic plants with introduced useful agronomic traits have been obtained in several instances. This rapid and impressive progress in the genetic manipulation of cereals has been made possible by two critical technical advances during the past decade: the establishment of embryogenic suspension cultures as a source of totipotent protoplasts and the direct delivery of DNA into protoplasts for genetic transformation. 相似文献
14.
Genetic engineering of cytokinin metabolism: Prospective way to improve agricultural traits of crop plants 总被引:1,自引:0,他引:1
David Zalabák Hana Pospíšilová Mária Šmehilová Katarína Mrízová Ivo Frébort Petr Galuszka 《Biotechnology advances》2013
Cytokinins (CKs) are ubiquitous phytohormones that participate in development, morphogenesis and many physiological processes throughout plant kingdom. In higher plants, mutants and transgenic cells and tissues with altered activity of CK metabolic enzymes or perception machinery, have highlighted their crucial involvement in different agriculturally important traits, such as productivity, increased tolerance to various stresses and overall plant morphology. Furthermore, recent precise metabolomic analyses have elucidated the specific occurrence and distinct functions of different CK types in various plant species. Thus, smooth manipulation of active CK levels in a spatial and temporal way could be a very potent tool for plant biotechnology in the future. This review summarises recent advances in cytokinin research ranging from transgenic alteration of CK biosynthetic, degradation and glucosylation activities and CK perception to detailed elucidation of molecular processes, in which CKs work as a trigger in model plants. The first attempts to improve the quality of crop plants, focused on cereals are discussed, together with proposed mechanism of action of the responses involved. 相似文献
15.
A decade of progress in understanding vitamin E synthesis in plants 总被引:10,自引:0,他引:10
DellaPenna D 《Journal of plant physiology》2005,162(7):2622-737
The chloroplasts of higher plants contain and elaborate many unique biochemical pathways that produce an astonishing array of compounds that are vital for plastid function and are also important from agricultural and nutritional perspectives. One such group of compounds is the tocochromanols (more commonly known as Vitamin E), which is a class of four tocopherols and four toctorienols, lipid-soluble antioxidants that are only synthesized by plants and other oxygenic, photosynthetic organisms. Though the essential nature of tocopherols in mammalian diets was recognized over 80 years ago and the biosynthetic pathway in plants and algae elucidated in the late 1970s and early 80s, it has only been in the past decade that the genes and proteins for tocopherol synthesis have finally been isolated and characterized. The use of model plant and cyanobacterial systems has driven this gene discovery to the point that manipulation of tocopherol levels and types in various plant tissues and crops is becoming a reality. This article reviews progress since 1996 in the molecular and genetic understanding of tocopherol synthesis in the model photosynthetic organisms Arabidopsis thaliana and Synechocystis PCC6803 as a primer for current and future efforts to manipulate the levels of this essential nutrient in food crops by breeding and transgenic approaches. 相似文献
16.
A leaf-based regeneration and transformation system for maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) 总被引:3,自引:0,他引:3
Efficient methods for in vitro propagation, regeneration, and transformation of plants are of pivotal importance to both basic
and applied research. While being the world’s major food crops, cereals are among the most difficult-to-handle plants in tissue
culture which severely limits genetic engineering approaches. In maize, immature zygotic embryos provide the predominantly
used material for establishing regeneration-competent cell or callus cultures for genetic transformation experiments. The
procedures involved are demanding, laborious and time consuming and depend on greenhouse facilities. We have developed a novel
tissue culture and plant regeneration system that uses maize leaf tissue and thus is independent of zygotic embryos and greenhouse
facilities. We report here: (i) a protocol for the efficient induction of regeneration-competent callus from maize leaves
in the dark, (ii) a protocol for inducing highly regenerable callus in the light, and (iii) the use of leaf-derived callus
for the generation of stably transformed maize plants. 相似文献
17.
In the ongoing process of developing Brachypodium distachyon as a model plant for temperate cereals and forage grasses, we have developed a high-throughput Agrobacterium-mediated transformation system for a diploid accession. Embryogenic callus, derived from immature embryos of the accession BDR018, were transformed with Agrobacterium tumefaciens strain AGL1 carrying two T-DNA plasmids, pDM805 and pWBV-Ds-Ubi-bar-Ds. Transient and stable transformation efficiencies were optimised by varying the pre-cultivation period, which had a strong effect on stable transformation efficiency. On average 55% of 17-day-old calli co-inoculated with Agrobacterium regenerated stable transgenic plants. Stable transformation frequencies of up to 80%, which to our knowledge is the highest transformation efficiency reported in graminaceous species, were observed. In a study of 177 transgenic lines transformed with pDM805, all of the regenerated transgenic lines were resistant to BASTA((R)), while the gusA gene was expressed in 88% of the transgenic lines. Southern blot analysis revealed that 35% of the tested plants had a single T-DNA integration. Segregation analysis performed on progenies of ten selected T(0) plants indicated simple Mendelian inheritance of the two transgenes. Furthermore, the presence of two selection marker genes, bar and hpt, on the T-DNA of pWBV-Ds-Ubi-bar-Ds allowed us to characterize the developed transformation protocol with respect to full-length integration rate. Even when not selected for, full-length integration occurred in 97% of the transformants when using bialaphos as selection agent. 相似文献
18.
Michela Janni Tiziana Bozzini Michela Di Giovanni Ilaria Moscetti Roberta Lupi Andrea Gennaro Chiara Volpi Stefania Masci Renato D’Ovidio 《Plant Cell, Tissue and Organ Culture》2018,132(3):461-467
Plant genetic transformation and regeneration has become a valuable research tool for functional genomics. A successful transformation event involves the transfer of the target gene into a suitable explant, the integration and expression of the transgene into the host genome and the regeneration of the fertile transgenic plants from the transformed tissues. Wheat is considered as a recalcitrant species even if many efforts have been done in recent years to improve transformation efficiency. The transformation of its progenitors has never been attempted, even though the possibility to transform wild hemmer represents a valuable tool to evaluate structural and functional variability occurring in wild hemmer and explaining its higher adaptation to abiotic stresses. In this paper we report, as far as we know, for the first time, the microparticle transformation of immature embryos of the wild hemmer Triticum dicoccoides with the Tapgip1 gene. The transformation method was successfully transferred from durum wheat and several transgenic lines were obtained. Its application for the exploitation of wheat progenitors for molecular breeding is of great relevance for genomic and functional genomics studies. This result, indeed, opens new perspectives in complementation studies for the comprehension of durum and bread wheat adaptation mechanisms to stresses. 相似文献
19.
20.
María-José Coronado Götz Hensel Sylvia Broeders Ingrid Otto Jochen Kumlehn 《Acta Physiologiae Plantarum》2005,27(4):591-599
Barley transformation mediated by Agrobacterium tumefaciens is routinely performed in a number of laboratories. However, elimination of selectable marker genes and formation of plants
homozygous for the transgene via conventional segregation is laborious and time-consuming. Here we suggest a concept that
includes the production of primary transgenic plants via infection of immature embryos with A. tumefaciens followed by androgenetic generation of a segregating population of entirely homozygous plants. Selectable marker-free, truebreeding
plants carrying a single-opy transgene integrant may thus be efficiently and rapidly obtained. However, amenability to Agrobacterium-mediated transformation as well as androgenetic potential is genotype-dependent. Efficient genetic transformation by infection
of immature embryos is so far confined to the spring type cultivar ‘Golden Promise’ which, however, turned out to be recalcitrant
in pollen embryogenesis. To facilitate androgenetic generation of homozygous segregants from primary transformants, we have
established a method for embryogenic pollen culture in cv. Golden Promise that includes conventional cold-treatment and subsequent
preculture of immature pollen under starvation conditions prior to transfer to complete nutrient medium. Further we show that
conditioning of the pollen culture medium by co-culture of immature wheat pistils as well as addition of pistil-preconditioned
medium considerably support androgenetic development. Employment of the established method using immature pollen of primary
transgenic plants demonstrates that selectable marker-free, true-breeding transgenic progeny can be rapidly obtained pursuing
the concept proposed. The protocol presented will be useful in functional genomics as well as in molecular breeding approaches. 相似文献