[Plant virus, yesterday and today].
Explore the source record for details and available documents.
Genetic Engineering↗
SEARCH · Search PubMed
Results for “Plant engineering”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Genetic engineering of drought resistant potato plants by introduction of the trehalose-6-phosphate synthase (TPS1) gene from Saccharomyces cerevisiae.
In yeast, trehalose-6-phosphate synthase is a key enzyme for trehalose biosynthesis, encoded by the structural gene TPS1. Trehalose affects sugar metabolism as well as osmoprotection against several environmental stresses, such as heat and desiccation. The TPS1 gene of Saccharomyces cerevisiae was engineered under the control of the CaMV 35S promoter for constitutive expression in transgenic potato plants by Ti-plasmid of Agrobacterium-mediated transformation. The resulting TPS1 transgenic potato plants exhibited various morphological phenotypes in culture tubes, ranging from normal to severely retarded growth, including dwarfish growth, yellowish lancet-shaped leaves, and aberrant root development. However, the plants recovered from these negative growth effects when grown in a soil mixture. The TPS1 transgenic potato plants showed significantly increased drought resistance. These results suggest that the production of trehalose not only affects plant development but also improves drought tolerance.
Agrobacterium tumefaciens↗
Transgenic analysis of sugar beet xyloglucan endo-transglucosylase/hydrolase Bv-XTH1 and Bv-XTH2 promoters reveals overlapping tissue-specific and wound-inducible expression profiles.
The identification and analysis of tissue-specific gene regulatory elements will improve our knowledge of the molecular mechanisms that control the growth and development of different plant tissues and offer potentially useful tools for the genetic engineering of plants. A polymerase chain reaction (PCR)-based 5'-genome walk from sequences of an isolated sugar beet xyloglucan endo-transglucosylase hydrolase (XTH) gene led to the isolation of two independent upstream fragments. They were 1332 and 2163 base pairs upstream of the XTH ATG start site, respectively. In vivo transgenic assays in sugar beet hairy roots and Arabidopsis thaliana revealed that both fragments had promoter function and, in A. thaliana, directed expression in vascular tissues within the root, leaves and petals. Promoter activity was also observed in the leaf trichomes and within rapidly expanding stem internodes. Expression driven by both promoters was found to be wound inducible. Overall, the spatial and temporal expression pattern of these promoters suggested that the corresponding Bv-XTH genes (designated Bv-XTH1 and Bv-XTH2) may be involved in secondary cell wall formation. This work provides new insights on molecular mechanisms that could be exploited for the genetic engineering of sugar beet crops.
Journal Article↗
Ex planta phytoremediation of trichlorophenol and phenolic allelochemicals via an engineered secretory laccase.
Plant roots release a range of enzymes capable of degrading chemical compounds in their immediate vicinity. We present a system of phytoremediation ex planta based on the overexpression of one such enzyme, a secretory laccase. Laccases catalyze the oxidation of a broad range of phenolic compounds, including polychlorinated phenols such as 2,4,6-trichlorophenol (TCP), that are among the most hazardous and recalcitrant pollutants in the environment. We isolated a secretory laccase cDNA of LAC1, which is specifically expressed in the roots of Gossypium arboreum (cotton). Transgenic Arabidopsis thaliana plants overexpressing LAC1 exhibited enhanced resistance to several phenolic allelochemicals and TCP. The secretory laccase activity in these plants was responsible for the conversion of sinapic acid into a mono-lactone type dimer and for the transformation of TCP.
Arabidopsis↗
Analysis of the transient increase in cytosolic Ca2+ during the action potential of higher plants with high temporal resolution: requirement of Ca2+ transients for induction of jasmonic acid biosynthesis and PINII gene expression.
Plants respond to various abiotic stimuli by activation and propagation of fast electrical signals, action potentials. To resolve the temporal increase in cytosolic Ca(2)(+) during the action potentials of higher plants, we regenerated transgenic potato plants that expressed the Ca(2)(+) photoprotein apoaequorin. These genetically engineered potato plants were used for simultaneous measurements of transient changes in the membrane potential and the Ca(2)(+) luminescence triggered by heat-induced action potentials. High temporal resolution for recording of the fast transient electrical and light signals was accomplished by a sampling rate of 1 kHz. Upon elicitation by heat the membrane potential depolarization preceded the rise of cytosolic Ca(2)(+) by 50-100 ms. Several Ca(2)(+) channel blockers were tested to inhibit the rise in cytosolic Ca(2)(+). Treatment of plants with Ruthenium Red blocked the elevation in cytosolic Ca(2)(+) that was associated with heat-stimulated action potentials. Furthermore, action potentials have been demonstrated to stimulate jasmonic acid biosynthesis and PINII gene expression. Therefore, we measured jasmonic acid and PINII gene expression levels subsequent to action potential initiation by a short heating pulse. As expected, jasmonic acid biosynthesis and PINII gene expression were induced by action potentials. Pretreatment of potato plants with Ruthenium Red inhibited induction of jasmonic acid biosynthesis and PINII gene expression that was generally triggered by heat-activated action potentials.
Action Potentials↗
[Study on the identification of genomic modified foods].
Nucleotide-based amplification method is an important system for the identification of genomic modified foods (GMF). Roundup Ready Soybeans (Monsanto company), Bt 176 GM maize (Novartis/Ciba-Geigy company) and Cecropin D capsicum was used as material to search for the feasibility of investigating the safety of GMF by PCR method. Primers specific for inserted genes and crop endogenous genes in Roundup Ready Soybeans, Bt 176 maize and Cecropin D capsicum were applied. The discrimination system for GM soybeans, GM maize and GM capsicum from the counterpart of non-GM products and the detection system for correlating marker genes and transgenes are established. The method was easy and fast, and the corresponding results fixed the standard or declared data.
Capsicum↗
[Analysis of nuclear and mitochondrial genomes of transplastomic Salpiglossis sinuata plants obtained by transfer of transformed plastids from N. tabacum (+S. sinuata) cybrid].
New model system of plastid transformation has been proposed using a wild representative of Solanaceae family--S. sinuata. Earlier obtained cybrid plants N. tabacum (+ S. sinuata) were used for transformation experiments by PEG treatment of protoplasts with aadA gene that confers resistance to spectinomycin. Transformed S. sinuata plastome was transferred from N. tabacum (+ S. sinuata) cybrid to S. sinuata wild type plants by somatic hybridization. Molecular analysis of nuclear and mitochondrial DNA has been performed.
DNA, Mitochondrial↗
Engineering resistance against viral diseases in plants.
Explore the source record for details and available documents.
Genes, Viral↗
Biotechnological production of plant-based insecticides.
The demand for natural and nonpersistent insecticides is increasing day by day. Plant cell cultures could be an alternative to conventional methods of production of insecticides from field-grown plants. In vitro cultured plant cells produce a wide array of insecticides as a part of their secondary metabolism. Their ability to synthesize key enzymes and the manipulation of these could lead to the enhanced production of many insecticides of industrial importance. The development of a high-yielding hairy root culture system for thiophenes, nicotine, and phytoecdysones is of considerable interest. In this article, the current literature on various factors that influence the growth, production, and secretion of six insecticidal compounds, namely, pyrethrins, azadirachtin, thiophenes, nicotine, rotenoids, and phytoecdysones which have been prospects for the scale-up of cell cultures, genetic engineering to obtain transgenic plants, and metabolically engineered plants for increased production of bio-molecules, has been discussed. Environmental safety clearance and the future prospects of application of biomolecules for plant-derived insecticides are presented.
Biotechnology↗
[Agrobacterium-mediated medicinal plant transformation].
Explore the source record for details and available documents.
Genetic Engineering↗
Engineering DNA vaccines that include plant virus coat proteins.
Explore the source record for details and available documents.
Animals↗
[Prevalence of hypertension among railroad engine operators at a metallurgical plant].
The article comments on a study of the labour conditions peculiarities of industrial rail-way engine operators and the epidemiology of hypertension disease in this professional group. 962 persons (both mechanics and their subordinates) were examined, all of them males, 20-59 years of age, with the duration of work: less than 10 years--366 cases, 11-20 years--483 cases, over 20 years--113 cases. The analysis of hypertension prevalence revealed that the morbidity rate was markedly higher among the engine teams' personnel as compared with the depot workers. The morbidity rate difference between the industrial rail-way engine mechanics and main-line engine mechanics was insignificant. The high morbidity rate necessitates improvements of the labour conditions, e.g. working shift cuts, establishment of physical rehabilitation and psycho-emotional relaxation units, as well as rational diet.
Adult↗
Engineering drought and salinity tolerance in plants: lessons from genome-wide expression profiling in Arabidopsis.
World food security is increasingly dependent on continuous crop improvement and, in particular, the development of crops with increased drought and salinity tolerance. The completed genomic sequence of the model plant Arabidopsis thaliana and the development of whole-genome microarrays, together with increasing repositories of publicly available data and data analysis tools, have opened new avenues to genome-wide systemic analysis of plant stress responses. Here we outline examples of how this full-genome expression profiling can contribute to our understanding of complex stress responses and the identification and evaluation of novel transgenes that could hold the key to the development of commercially viable and sustainable crop plants.
Arabidopsis↗
Mucosal and systemic immunization elicited by Newcastle disease virus (NDV) transgenic plants as antigens.
As a step towards developing a safe and effective edible vaccine against Newcastle disease virus (NDV), we have explored the use of plants genetically engineered to express viral proteins. We report the construction of transgenic potato plants expressing the genes coding for immunogenic proteins of NDV under the regulation of CaMV 35S promoter and its immunogenicity in mice. All mice receiving transgenic plant extracts in incomplete Freund adjuvant produced specific anti-NDV antibodies. Animals fed with transgenic leaves showed a specific response against NDV. Detection of IgA released from in vitro-cultured intestinal tissue fragments indicated the presence of IgA-secreting cells in the gut.
Animals↗
Drought-induced responses in plant cells.
Plants subjected to water stress undergo numerous physiological and metabolic changes. A general decrease in photosynthetic rate is among the most common responses. This is due to a programmed process involving the closure of stomata and reduction in the activity of photosynthetic enzymes. The plant hormone abscisic acid plays an important role in this process. Accumulation of compatible solutes, during water stress, is thought to be an adaptive response which has been developed by some plant species. Engineering the genes involved in the synthesis of these compounds, into nonaccumulating plants, has demonstrated promising results for genetic improvement of drought tolerance. Drought stress induces alteration of gene expression. A large number of genes which are upregulated by water stress have been isolated and characterized. Proteins encoded by some of these genes share several characteristics. The biochemical role of most of these gene products is unknown, but potential adaptive functions have been suggested. Abscisic acid is involved in the regulation of some of these genes.
Adaptation, Physiological↗
Broad virus resistance in transgenic plants.
Viruses are significant threats to agricultural crops worldwide and the limited sources of natural resistance warrant the development of novel resistance sources. Several methods of transgenic protection have been successfully applied, including protein- and RNA-mediated approaches. Increased understanding of the molecular biology of virus infection is starting to bear fruit, enabling specific strategies to be designed for virus resistance in crops.
Crops, Agricultural↗
Phytoextraction of metals and metalloids from contaminated soils.
The removal of inorganic contaminants by plants is termed phytoextraction. Recent studies have looked at the feasibility of phytoextraction, and demonstrate that both good biomass yields and metal hyperaccumulation are required to make the process efficient. Adding chelating agents to soil to increase the bioavailability of contaminants can sometimes induce hyperaccumulation in normal plants, but may produce undesirable environmental risks. Thus, it is necessary to investigate the mechanisms responsible for hyperaccumulation, using natural hyperaccumulators as model plant species. Recent advances have been made in understanding the mechanisms responsible for hyperaccumulation of Zn, Cd, Ni and As by plants. Attempts to engineer metal tolerance and accumulation have so far been limited to Hg, As and Cd, and although promising results have been obtained they may be some way from practical application. More fundamental understanding of the traits and mechanisms involved in hyperaccumulation are needed so that phytoextraction can be optimised.
Chelating Agents↗
Overexpression of DWARF4 in the brassinosteroid biosynthetic pathway results in increased vegetative growth and seed yield in Arabidopsis.
Plants unable to synthesize or perceive brassinosteroids (BRs) are dwarfs. Arabidopsis dwf4 was shown to be defective in a steroid 22alpha hydroxylase (CYP90B1) step that is the putative rate-limiting step in the BR biosynthetic pathway. To better understand the role of DWF4 in BR biosynthesis, transgenic Arabidopsis plants ectopically overexpressing DWF4 (AOD4) were generated, using the cauliflower mosaic virus 35S promoter, and their phenotypes were characterized. The hypocotyl length of both light- and dark-grown AOD4 seedlings was increased dramatically as compared to wild type. At maturity, inflorescence height increased >35% in AOD4 lines and >14% in tobacco DWF4 overexpressing lines (TOD4), relative to controls. The total number of branches and siliques increased more than twofold in AOD4 plants, leading to a 59% increase in the number of seeds produced. Analysis of endogenous BR levels in dwf4, Ws-2 and AOD4 revealed that dwf4 accumulated the precursors of the 22alpha-hydroxylation steps, whereas overexpression of DWF4 resulted in increased levels of downstream compounds relative to Ws-2, indicative of facilitated metabolic flow through the step. Both the levels of DWF4 transcripts and BR phenotypic effects were progressively increased in dwf4, wild-type and AOD4 plants, respectively. This suggests that it will be possible to control plant growth by engineering DWF4 transcription in plants.
Arabidopsis↗