Search results for "nicotiana tabacum"

Nicotiana tabacum L. hloroplastu izmantošanas iespējas cilvēku cilmes šūnu barotņu bagātināšanai un cilmes šūnu proliferācijas un morfoloģisko izmaiņ…

2016

Lai izvērtētu izolētu tabakas hloroplastu potenciālu kā cilmes šūnu barotni bagātinošu līdzekli, FM-55-P cilvēka melanomas šūnas tika inkubētas 2 dienas ar izolētiem hloroplastiem, kas tika pievienoti šūnu kultūrai kā barotnes atšķaidījums vai kā hloroplastu piedeva. Tika noskaidrots, ka hloroplastu piedeva barotnei neizraisa ievērojamu proliferācijas samazinājumu salīdzinot ar barotnes atšķaidījumu un ka hloroplastu piedevas klātbūtnē melanocīti vairāk atraujas no kultūras virsmas bez šūnu nāves pazīmēm. Hloroplasti barotnē šķietami sadalījās un tika iekļauti melanocītu citoplazmā visos pievienošanas variantos. Izolētu hloroplastu ietekme uz melanomas šūnu kultūru tika vērtēta kā neizteikt…

Nitric oxide production in tobacco leaf cells: a generalized stress response?

2003

The function of nitric oxide (NO), a gaseous free radical emitted by many plants, is incompletely understood. In the present study the hypothesis that NO generation, like that of the reactive oxygen species, occurs as a general response to different environmental cues was tested. Leaf peels and mesophyll cell suspensions of Nicotiana tabacum cv. Xanthi were loaded with the NO-specific fluorophore, diaminofluorescein, and subjected to an abiotic stressor. Light stress and mechanical injury had no apparent effect on NO production. In contrast, high temperatures, hyperosmotic stress, salinity and epi-illumination in a microscope all led to rapid surges in NO-induced fluorescence. The fluoresce…

Inhibition of trehalose breakdown increases new carbon partitioning into cellulosic biomass in Nicotiana tabacum

2010

Abstract Validamycin A was used to inhibit in vivo trehalase activity in tobacco enabling the study of subsequent changes in new C partitioning into cellulosic biomass and lignin precursors. After 12-h exposure to treatment, plants were pulse labeled using radioactive 11 CO 2 , and the partitioning of isotope was traced into [ 11 C]cellulose and [ 11 C]hemicellulose, as well as into [ 11 C]phenylalanine, the precursor for lignin. Over this time course of treatment, new carbon partitioning into hemicellulose and cellulose was increased, while new carbon partitioning into phenylalanine was decreased. This trend was accompanied by a decrease in phenylalanine ammonia-lyase activity. After 4 d o…

Flux of protons released by wild type and ferritin over-expressor tobacco plants : effect of phosphorus and iron nutrition

2003

Abstract Tobacco ( Nicotiana tabacum ) plants over-expressing the iron storage protein ferritin, either in the cytoplasm or in the plastids, were grown under various P and Fe conditions. The crossed effects of both the genotypes and the environmental conditions on iron and chlorophyll concentrations in leaves, ferric reductase (EC 1.6.99.13) and plasmalemma H + -ATPase (EC 3.6.3.6) activities in roots, and fluxes of H + released by roots were determined. The increase in leaf Fe concentration observed in plants over-expressing ferritin was accompanied by an increase in root ferric reductase and H + -ATPase activities. Iron deficient conditions induced a decrease in Fe and chlorophyll concent…

Early signaling network in tobacco cells elicited with methyl jasmonate and cyclodextrins.

2012

We analyze, for the first time, the early signal transduction pathways triggered by methyl jasmonate (MJ) and cyclodextrins (CDs) in tobacco (Nicotiana tabacum) cell cultures, paying particular attention to changes in cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)), the production of hydrogen peroxide (H(2)O(2)) and nitric oxide (NO), and late events like the induction of capsidiol. Our data indicate that MJ and CDs trigger a [Ca(2+)](cyt) rise promoted by Ca(2+) influx through Ca(2+)-permeable channels. The joint presence of MJ and CDs provokes a first increase in [Ca(2+)](cyt) similar to that observed in MJ-treated cells, followed by a second peak similar to that found in the presence…

The First Cell Division Cycle in Nicotiana Mesophyll Protoplasts Cultured in Vitro. I. Methods to Determine Cycle Kinetics

1991

Summary The progress of freshly isolated and in vitro cultured mesophyll protoplasts through the first mitotic cycle was studied with the aim of determining the frequency and timing of the G2-phase. Putative G1 and G2 phase cells were identified by measuring the relative DNA content through improved cytofluorimetry of DAPI-stained nuclei. S-phase nuclei were identified by labelling with the thymidine-analogue BrdU, which was subsequently immuno-localized with a BrdU-specific monoclonal antibody. The cells entered S-phase after 12–24h and a maximum of G2 cells was observed 24–36h after culture initiation. Most of the cells had divided after 48 to 72 h.

Determination of total ribonucleotide pool in plant materials by high-pH anion-exchange high-performance liquid chromatography following extraction w…

2005

A new, improved method that only requires a potassium hydroxide extraction procedure is presented for the analysis of a full nucleotide pool in plant materials. Quantification was performed by high-pH anion-exchange chromatography (HPAEC) with UV detection after a potassium hydroxide extraction, and allowed the quantification of 13 linear ribonucleotides in a single run. The method has been validated by comparison of six extraction methods and also by measurement of the intracellular nucleotide levels of three plant species (cell cultures and leaves). The evolution of the nucleotide pool of Nicotiana tabacum cell culture during growth has also been measured, and showed an increase in the po…

Membrane dynamics of sugar transports in tobacco-microbe interactions

2017

SPEINRAUBIPM DOCT; Plants can influence microorganism population through exudation of sugars notably as carbon source. Indeed, the type of plant-microorganism interaction (PMI) is linked to the trophic exchanges between plant and microorganism. Microorganisms are thus able to “manipulate” the host to modify sugar fluxes. In mycorrhizal symbiosis, the plant has a supply of nutrients by the fungal partner, which in return receives sugars. In pathogenic relationship, the microorganism will divert sugars provided by the plant without compensation. Despite identification of sugar transporters at biotrophic interfaces, molecular and cellular mechanisms by which microorganisms operate the distribu…

Calcium signaling in plant defense: involvement of subcellular compartments and glutamate receptorsCalcium signaling in plant defense: involvement of…

2012

Réponses des cellules de Nicotiana tabacum à des molécules microbiennes : évènements de signalisation précoce, influence de la dynamique membranaire …

2018

Responses of Nicotiana tabacum cells to microbial molecule treatments: early signaling events,influence of membrane dynamics, and sugar fluxesIn their natural environment plants are in close interaction with beneficial, neutral, or pathogenicmicrobes, which are highly dependent on carbon resources exuded by plant roots. Sugar transport, which isa key process of plant physiology, is essential to support the fate of plant-microbe interactions. Duringevolution, plants have acquired the ability to perceive microbial molecules, initiating specific signaltransduction cascades and leading to adapted response for microbe lifestyles (avirulent, virulent, or benefic).Plant survival will depend on the…