403 research outputs found
Long regions of homologous DNA are incorporated into the tobacco plastid genome by transformation.
Dynamic of hemodynamic parameters in patients operated with atrial septal defects depending on the age
Spitalul Clinic Republican, Centrul de Chirurgie a Inimii, Chişinău, Republica Moldova, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Defectul septal atrial (DSA) reprezintă circa 10% din toate malformaţiile congenitale și apare ceva mai des la
femei decât la bărbaţi (în raport de circa 2:1).
Material şi metode: Pentru studiul rezultatelor intervenţiilor chirurgicale la distanţă a pacienţilor cu DSA au fost examinaţi 186
(87,3%) pacienţi, dintre care (139 femei şi 47 bărbaţi, cu vârstele de la 2 la 59 ani; 78 pacienţi aveau vârsta de 2-18 ani; 40 de
pacienţi cu vârsta de 19-29 ani; 35 de pacienţi cu vârsta de 30-39 ani; 27 de pacienţi cu vârsta de 40-49 ani şi 6 pacienţi de 50
de ani şi mai mult. Au fost evaluaţi în dinamică parametrii ecocardiografici la pacienţii operaţi cu DSA (preoperator, postoperator
la o săptămână, la a 6-a lună, la 24 şi 48 luni).
Rezultate: Evoluţia postoperatorie a fost bună la toţi pacienţii, însă gradul de ameliorare a indicatorilor hemodinamici a depins
de vârsta la care s-a efectuat intervenţia chirurgicală. În special diminuarea considerabilă a dimensiunilor cavităţilor drepte a
inimii precum şi a presiunii sistolice în ventriculul drept se înregistrează imediat postoperator.
Concluzii: Evoluţia în timp a fost bună în lotul de pacienţi cu vârsta sub 18 ani, satisfăcătoare la pacienţii cu vârsta de 19-29 ani
şi 30-39 ani. Rezultate mai puţin satisfăcătoare s-au obţinut la pacienţii cu vârsta de peste 40 de ani, la care hipertensiunea
pulmonară şi dilatarea cavităţilor drepte ale inimii persistau în timp.Introduction: Atrial septal defect (ASD) represents approximately 10% of all congenital malformations and develops
predominantly in women with female to male ratio of near 2:1.
Material and methods: For the assessment of long-term results of surgery in the patients with ASD 186 (87.3%) patients were
examined. Women were 139 and men – 47, aged from 2 to 29 years. Thirty five patients were from 30 to 39 years, 27 patients
were from 40 to 49 years and 6 patients were aged 50 years or more. Ecographic parameters in patients with ASD were
evaluated in dynamic (preoperatively and postoperatively at one weak, at 6 months, at 24 and 48 months).
Results: Postoperative evolution was good at almost all patients, but the grade of improvement of homodynamic indexes was
depending on patient’s age, at which he or she was operated. Especially a considerable diminishing of the size of the heart’s
right cavities and of the systolic pressure in the right ventricle was detected immediately after the surgery.
Conclusions: Evolution in time was good in the group of patients with age lower than 18 years, satisfactory in those of 19-29
years and 30-39. Less satisfactory results were reached in patients over 40 years, whose pulmonary hypertension and dilatation
of right heart cavities persisted in time
Chemical Composition of the Essential Oils of Three Ocimum basilicum L. Cultivars from Serbia
Basil essential oil (BEO) contains a wide range of chemical compounds whose content may vary depending on chemotypes, environmental conditions, agronomic techniques and particularly the origin of the plant. In our present study, essential oils (EOs) were isolated by hydrodistillation method from dry herbs of three basil cultivars and analyzed by GC-FID and GC-MS. Two of the tested cultivars belong to sweet basil group (B-1 and B-2) while the third one was large leafed 'Genovese' basil (B-3). EO content in the dry herb was 0.65%, 0.41% and 0.62% respectively. The main classes of compounds of B1EO and B3EO were sesquiterpene hydrocarbons (38.39% and 37.95%), oxygenated monoterpenes (25.44% and 28.04%) and phenylpropanoids (17.43% and 15.71%). The main constituents of both EOs were monoterpene alcohol linalool (13.68% and 15.38%), phenoyl derivate eugenol (10.83% and 8.97%) and sesquiterpene hydrocarbon alpha-bergamotene (8.12% and 9.25%). In both EOs, epi-bicyclosesquiphellandrene was detected in considerable amount (7.03% and 8.07%). The most abundant compound classes in B2EO were oxygenated monoterpenes (52.07%), sesquiterpene hydrocarbons (24.27%) and phenylpropanoids (10.95%). Linalool was the dominant compound (40.97%), followed by epi-bicyclosesquiphellandrene (8.70%) and methyl chavicol (7.92%). The results showed complex chemical composition of BEOs and pointed out the presence of biologically active compounds of importance for different branches of the pharmaceutical, chemical and food industry. Although there are differences in the chemical composition of the BEOs, the obtained results show that all of the tested cultivars are rich in compounds which are responsible for biological activities
A comparative study of Tam3 and Ac transposition in transgenic tobacco and petunia plants
Transposition of the Anthirrinum majus Tam3 element and the Zea mays Ac element has been monitored in petunia and tobacco plants. Plant vectors were constructed with the transposable elements cloned into the leader sequence of a marker gene. Agrobacterium tumefaciens-mediated leaf disc transformation was used to introduce the transposable element constructs into plant cells. In transgenic plants, excision of the transposable element restores gene expression and results in a clearly distinguishable phenotype. Based on restored expression of the hygromycin phosphotransferase II (HPTII) gene, we established that Tam3 excises in 30% of the transformed petunia plants and in 60% of the transformed tobacco plants. Ac excises from the HPTII gene with comparable frequencies (30%) in both plant species. When the β-glucuronidase (GUS) gene was used to detect transposition of Tam3, a significantly lower excision frequency (13%) was found in both plant species. It could be shown that deletion of parts of the transposable elements Tam3 and Ac, removing either one of the terminal inverted repeats (TIR) or part of the presumptive transposase coding region, abolished the excision from the marker genes. This demonstrates that excision of the transposable element Tam3 in heterologous plant species, as documented for the autonomous element Ac, also depends on both properties. Southern blot hybridization shows the expected excision pattern and the reintegration of Tam3 and Ac elements into the genome of tobacco plants.
Autoluminescent Plants
Prospects of obtaining plants glowing in the dark have captivated the imagination of scientists and layman alike. While light emission has been developed into a useful marker of gene expression, bioluminescence in plants remained dependent on externally supplied substrate. Evolutionary conservation of the prokaryotic gene expression machinery enabled expression of the six genes of the lux operon in chloroplasts yielding plants that are capable of autonomous light emission. This work demonstrates that complex metabolic pathways of prokaryotes can be reconstructed and function in plant chloroplasts and that transplastomic plants can emit light that is visible by naked eye
Brassica juncea chitinase BjCHI1 inhibits growth of fungal phytopathogens and agglutinates Gram-negative bacteria
Brassica juncea BjCHI1 is a plant chitinase with two chitin-binding domains. Its expression, induced in response to wounding, methyl jasmonate treatment, Aspergillus niger infection, and caterpillar Pieris rapae feeding, suggests that it plays a role in defence. In this study, to investigate the potential of using BjCHI1 in agriculture, Pichia-expressed BjCHI1 and its deletion derivatives that lack one or both chitin-binding domains were tested against phytopathogenic fungi and bacteria. Transplastomic tobacco expressing BjCHI1 was also generated and its extracts assessed. In radial growth-inhibition assays, BjCHI1 and its derivative with one chitin-binding domain showed anti-fungal activities against phytopathogens, Colletotrichum truncatum, C. acutatum, Botrytis cinerea, and Ascochyta rabiei. BjCHI1 also inhibited spore germination of C. truncatum. Furthermore, BjCHI1, but not its derivatives lacking one or both domains, inhibited the growth of Gram-negative bacteria (Escherichia coli, Ralstonia solanacearum, Pseudomonas aeruginosa) more effectively than Gram-positive bacteria (Micrococcus luteus and Bacillus megaterium), indicating that the duplicated chitin-binding domain, uncommon in chitinases, is essential for bacterial agglutination. Galactose, glucose, and lactose relieved agglutination, suggesting that BjCHI1 interacts with the carbohydrate components of the Gram-negative bacterial cell wall. Retention of chitinase and bacterial agglutination activities in transplastomic tobacco extracts implicates that BjCHI1 is potentially useful against both fungal and bacterial phytopathogens in agriculture
Tobacco plastid transformation using the feedback-insensitive anthranilate synthase [α]-subunit of tobacco (ASA2) as a new selectable marker
Genetic engineering of chloroplasts normally requires the stable introduction of bacterial derived antibiotic or herbicide-resistance genes as selective markers. Ecological and health concerns have been raised due to the presence of such genes within the environment or the food supply. One way to overcome this issue is the use of plant genes able to confer a metabolic or developmental advantage to the transformed cells manipulating the plant's biosynthetic pathways. We explored the feasibility of using, for plastid transformation, the selection system based on the feedback-insensitive anthranilate synthase (AS) α-subunit gene of tobacco (ASA2) as a new selective marker and the indole analogue 4-methylindole (4MI) or the tryptophan analogue 7-methyl-DL-tryptophan (7MT) as the selection agents. An expression cassette containing Prrn-ASA2 was effectively integrated into the region between accD and ycf4 of the tobacco plastome by the biolistic process. Plastid transgenic plants were obtained on medium supplemented with 300 μM 7MT or 4MI. Transplastomic plants showed normal phenotype and fertility and the resistance to the selection agents 7MT and 4MI was transmitted maternally. The plastid transformed lines also exhibited a higher level of AS enzyme activity that was less sensitive to Trp-feedback inhibition and, consequently, increased free Trp levels in leaves about 7-fold
Metabolic Adaptation in Transplastomic Plants Massively Accumulating Recombinant Proteins
BACKGROUND: Recombinant chloroplasts are endowed with an astonishing capacity to accumulate foreign proteins. However, knowledge about the impact on resident proteins of such high levels of recombinant protein accumulation is lacking. METHODOLOGY/PRINCIPAL FINDINGS: Here we used proteomics to characterize tobacco (Nicotiana tabacum) plastid transformants massively accumulating a p-hydroxyphenyl pyruvate dioxygenase (HPPD) or a green fluorescent protein (GFP). While under the conditions used no obvious modifications in plant phenotype could be observed, these proteins accumulated to even higher levels than ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), the most abundant protein on the planet. This accumulation occurred at the expense of a limited number of leaf proteins including Rubisco. In particular, enzymes involved in CO(2) metabolism such as nuclear-encoded plastidial Calvin cycle enzymes and mitochondrial glycine decarboxylase were found to adjust their accumulation level to these novel physiological conditions. CONCLUSIONS/SIGNIFICANCE: The results document how protein synthetic capacity is limited in plant cells. They may provide new avenues to evaluate possible bottlenecks in recombinant protein technology and to maintain plant fitness in future studies aiming at producing recombinant proteins of interest through chloroplast transformation
Insensitivity of chloroplast gene expression to DNA methylation
Presence and possible functions of DNA methylation in plastid genomes of higher plants have been highly controversial. While a number of studies presented evidence for the occurrence of both cytosine and adenine methylation in plastid genomes and proposed a role of cytosine methylation in the transcriptional regulation of plastid genes, several recent studies suggested that at least cytosine methylation may be absent from higher plant plastid genomes. To test if either adenine or cytosine methylation can play a regulatory role in plastid gene expression, we have introduced cyanobacterial genes for adenine and cytosine DNA methyltransferases (methylases) into the tobacco plastid genome by chloroplast transformation. Using DNA cleavage with methylation-sensitive and methylation-dependent restriction endonucleases, we show that the plastid genomes in the transplastomic plants are efficiently methylated. All transplastomic lines are phenotypically indistinguishable from wild-type plants and, moreover, show no alterations in plastid gene expression. Our data indicate that the expression of plastid genes is not sensitive to DNA methylation and, hence, suggest that DNA methylation is unlikely to be involved in the transcriptional regulation of plastid gene expression
Balanced gene losses, duplications and intensive rearrangements led to an unusual regularly sized genome in Arbutus unedo chloroplasts
Completely sequenced plastomes provide a valuable source of information about the duplication, loss, and transfer events of chloroplast genes and phylogenetic data for resolving relationships among major groups of plants. Moreover, they can also be useful for exploiting chloroplast genetic engineering technology. Ericales account for approximately six per cent of eudicot diversity with 11,545 species from which only three complete plastome sequences are currently available. With the aim of increasing the number of ericalean complete plastome sequences, and to open new perspectives in understanding Mediterranean plant adaptations, a genomic study on the basis of the complete chloroplast genome sequencing of Arbutus unedo and an updated phylogenomic analysis of Asteridae was implemented. The chloroplast genome of A. unedo shows extensive rearrangements but a medium size (150,897 nt) in comparison to most of angiosperms. A number of remarkable distinct features characterize the plastome of A. unedo: five-fold dismissing of the SSC region in relation to most angiosperms; complete loss or pseudogenization of a number of essential genes; duplication of the ndhH-D operon and its location within the two IRs; presence of large tandem repeats located near highly re-arranged regions and pseudogenes. All these features outline the primary evolutionary split between Ericaceae and other ericalean families. The newly sequenced plastome of A. unedo with the available asterid sequences allowed the resolution of some uncertainties in previous phylogenies of Asteridae
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