Expression of human dopamine receptor in potato (Solanum tuberosum) results in altered tuber carbon metabolism

BACKGROUND: Even though the catecholamines (dopamine, norepinephrine and epinephrine) have been detected in plants their role is poorly documented. Correlations between norepinephrine, soluble sugars and starch concentration have been recently reported for potato plants over-expressing tyrosine decarboxylase, the enzyme mediating the first step of catecholamine synthesis. More recently norepinephrine level was shown to significantly increase after osmotic stress, abscisic acid treatment and wounding. Therefore, it is possible that catecholamines might play a role in plant stress responses by modulating primary carbon metabolism, possibly by a mechanism similar to that in animal cells. Since to date no catecholamine receptor has been identified in plants we transformed potato plants with a cDNA encoding human dopamine receptor (HD1). RESULTS: Tuber analysis of transgenic plants revealed changes in the activities of key enzymes mediating sucrose to starch conversion (ADP-glucose phosphorylase and sucrose synthase) and sucrose synthesis (sucrose phosphate synthase) leading to altered content of both soluble sugars and starch. Surprisingly the catecholamine level measured in transgenic plants was significantly increased; the reason for this is as yet unknown. However the presence of the receptor affected a broader range of enzyme activities than those affected by the massive accumulation of norepinephrine reported for plants over-expressing tyrosine decarboxylase. Therefore, it is suggested that the presence of the exogenous receptor activates catecholamine cAMP signalling in plants. CONCLUSIONS: Our data support the possible involvement of catecholamines in regulating plant carbon metabolism via cAMP signalling pathway

Omentin : a new adipokine within the new definition of the metabolic syndrome (IDF 2005)

Kontrowersje, jakie w ostatnich latach wywołało pojęcie zespołu metabolicznego, sprawiają, że związki hiperglikemii, dyslipidemii, otyłości, nadciśnienia i miażdżycy stały się obszarem szczególnie interesujących badań. Postęp wiedzy o patomechanizmach rządzących elementami zespołu metabolicznego może przybliżyć wyjaśnienie przyczyn głównych chorób cywilizacyjnych. Coraz większą uwagę zwraca się na endokrynną czynność trzewnej tkanki tłuszczowej. Jednym z wielu hormonów produkowanych przez tkankę tłuszczową jest omentyna -białko, którego funkcją prawdopodobnie jest zwiększanie wrażliwości na insulinę. Wyniki dalszych badań roli tej adipokiny mogą dostarczyć kolejnych dowodów na związki między składowymi zespołu metabolicznego.The diagnosis of metabolic syndrome became recently a controversial conception. Thus the associations between hyperglycaemia, dyslipidaemia, obesity, hypertension and atherosclerosis are the field of especially interesting research. The progress of our understanding into the pathogenesis of elements of the metabolic syndrome may help to explain the background of many diseases of westernised and developing societies. The endocrine role of the visceral adipose tissue is the focus of a number of scientific investigations. One of the mediators secreted by adipose tissue is omentin, a protein that functions as a factor increasing insulin sensitivity. Further research of the role of this adipokine may help to dissect the pathogenic background of the metabolic syndrome and consequently clarify its diagnosis

Omentin - a new adipokine within the new definition of the metabolic syndrome (IDF 2005)

Kontrowersje, jakie w ostatnich latach wywołało pojęcie zespołu metabolicznego, sprawiają, że związki hiperglikemii, dyslipidemii, otyłości, nadciśnienia i miażdżycy stały się obszarem szczególnie interesujących badań. Postęp wiedzy o patomechanizmach rządzących elementami zespołu metabolicznego może przybliżyć wyjaśnienie przyczyn głównych chorób cywilizacyjnych. Coraz większą uwagę zwraca się na endokrynną czynność trzewnej tkanki tłuszczowej. Jednym z wielu hormonów produkowanych przez tkankę tłuszczową jest omentyna - białko, którego funkcją prawdopodobnie jest zwiększanie wrażliwości na insulinę. Wyniki dalszych badań roli tej adipokiny mogą dostarczyć kolejnych dowodów na związki między składowymi zespołu metabolicznego.The diagnosis of metabolic syndrome became recently a controversial conception. Thus the associations between hyperglycaemia, dyslipidaemia, obesity, hypertension and atherosclerosis are the field of especially interesting research. The progress of our understanding into the pathogenesis of elements of the metabolic syndrome may help to explain the background of many diseases of westernised and developing societies. The endocrine role of the visceral adipose tissue is the focus of a number of scientific investigations. One of the mediators secreted by adipose tissue is omentin, a protein that functions as a factor increasing insulin sensitivity. Further research of the role of this adipokine may help to dissect the pathogenic background of the metabolic syndrome and consequently clarify its diagnosis

Glycosyltransferase efficiently controls phenylpropanoid pathway

<p>Abstract</p> <p>Background</p> <p>In a previous study, anthocyanin levels in potato plants were increased by manipulating genes connected with the flavonoid biosynthesis pathway. However, starch content and tuber yield were dramatically reduced in the transgenic plants, which over-expressed dihydroflavonol reductase (DFR).</p> <p>Results</p> <p>Transgenic plants over-expressing dihydroflavonol reductase (DFR) were subsequently transformed with the cDNA coding for the glycosyltransferase (UGT) of Solanum sogarandinum in order to obtain plants with a high anthocyanin content without reducing tuber yield and quality. Based on enzyme studies, the recombinant UGT is a 7-O-glycosyltransferase whose natural substrates include both anthocyanidins and flavonols such as kaempferol and quercetin. In the super-transformed plants, tuber production was much higher than in the original transgenic plants bearing only the transgene coding for DFR, and was almost the same as in the control plants. The anthocyanin level was lower than in the initial plants, but still higher than in the control plants. Unexpectedly, the super-transformed plants also produced large amounts of kaempferol, chlorogenic acid, isochlorogenic acid, sinapic acid and proanthocyanins.</p> <p>Conclusion</p> <p>In plants over-expressing both the transgene for DFR and the transgene for UGT, the synthesis of phenolic acids was diverted away from the anthocyanin branch. This represents a novel approach to manipulating phenolic acids synthesis in plants.</p

Episodic construction of the Tatra granitoid intrusion (Central Western Carpathians, Poland/Slovakia) : consequences for the geodynamics of Variscan collision and Rheic Ocean closure

The Tatra granitoid pluton (Central Western Carpathians, Poland/Slovakia) is an example of composite polygenetic intrusion, comprising many magmatic pulses varying compositionally from diorite to granite. The U– Pb LA-MC-ICP-MS zircon dating of successive magma batches indicates the presence of magmatic episodes at 370– 368, 365, 360, 355 and 350–340 Ma, all together covering a time span of 30 Ma of magmatic activity. The partial resorption and recycling of former granitoid material (“petrological cannibalism”) was a result of the incremental growth of the pluton and temperature in the range of 750–850 °C. The long-lasting granitoid magmatism was connected to the prolonged subduction of oceanic crust and collision of the Proto-Carpathian Terrane with a volcanic arc and finally with Laurussia, closing the Rheic Ocean. The differences in granitoid composition are the results of different depths of crustal melting. More felsic magmas were generated in the outer zone of the volcanic arc, whilst more mafic magmas were formed in the inner part of the supra-subduction zone. The source rocks of the granitoid magmas covered the compositional range of metapelite–amphibolite and were from both lower and upper crust. The presence of the inherited zircon cores suggests that the collision and granitoid magmatism involved crust of Cadomian consolidation age (c. 530 and 518 Ma) forming the Proto-Carpathian Terrane, crust of Avalonian affinity (462, 426 Ma) and melted metasedimentary rocks of volcanic arc provenance

Effects of genetic modifications to flax (Linum usitatissimum) on arbuscular mycorrhiza and plant performance

Although arbuscular mycorrhizal fungi (AMF) are known for their positive effect on flax growth, the impact of genetic manipulation in this crop on arbuscular mycorrhiza and plant performance was assessed for the first time. Five types of transgenic flax that were generated to improve fiber quality and resistance to pathogens, through increased levels of either phenylpropanoids (W92.40), glycosyltransferase (GT4, GT5), or PR2 beta-1,3-glucanase (B14) or produce polyhydroxybutyrate (M50), were used. Introduced genetic modifications did not change the degree of mycorrhizal colonization as compared to parent cultivars Linola and Nike. Arbuscules were well developed in each tested transgenic type (except M50). In two lines (W92.40 and B14), a higher abundance of arbuscules was observed when compared to control, untransformed flax plants. However, in some cases (W92.40, GT4, GT5, and B14 Md), the mycorrhizal dependency for biomass production of transgenic plants was slightly lower when compared to the original cultivars. No significant influence of mycorrhiza on the photosynthetic activity of transformed lines was found, but in most cases P concentration in mycorrhizal plants remained higher than in nonmycorrhizal ones. The transformed flax lines meet the demands for better quality of fiber and higher resistance to pathogens, without significantly influencing the interaction with AMF

Transcriptome profiling of flax plants exposed to a low-frequency alternating electromagnetic field

All living organisms on Earth evolved in the presence of an electromagnetic field (EMF), adapted to the environment of EMF, and even learned to utilize it for their purposes. However, during the last century, the Earth’s core lost its exclusivity, and many EMF sources appeared due to the development of electricity and electronics. Previous research suggested that the EMF led to changes in intercellular free radical homeostasis and further altered the expression of genes involved in plant response to environmental stresses, inorganic ion transport, and cell wall constituent biosynthesis. Later, CTCT sequence motifs in gene promoters were proposed to be responsible for the response to EMF. How these motifs or different mechanisms are involved in the plant reaction to external EMF remains unknown. Moreover, as many genes activated under EMF treatment do not have the CTCT repeats in their promoters, we aimed to determine the transcription profile of a plant exposed to an EMF and identify the genes that are directly involved in response to the treatment to find the common denominator of the observed changes in the plant transcriptome