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1.
Dagnija Vecstaudza Lelde Grantina-Ievina Galina Makarenkova Raimonds Kasparinskis Turs Selga Vilhelmine Steinberga 《Biocontrol Science and Technology》2018,28(4):341-358
The interrelations between biochar (BC) and soil microbiota remain unclear. Addressing this will be important for understanding how BC affects soil properties and plant growth. Here, we tested the influence of wood-derived BC with immobilised Trichoderma viride on rye Secale cereale L. in sandy soil. We found that the addition of BC leads to a significant (P?.05) increase in the concentrations of Ca2+ and Mg2+, as well as a decrease in the concentration of Al3+, irrespective of BC particle size and the presence of T. viride. Plant growth was stimulated in the presence of small (<2?mm) particle-sized BC. Fungal diversity, as well as an absolute and relative abundance of Trichoderma spp., was tested by cultivation-dependent methods and qPCR. Both of these approaches revealed a positive effect of BC on the survival of Trichoderma spp. under the tested conditions, especially in the presence of a small particle size fraction. 相似文献
2.
Rye (Secale cereale L.) plants were treated with an ethylene releaser ethephon (2-chloroethylphosphonic acid) in concentration of 4×10−2 M. We studied electron microscopically, if and how chloroplasts interact with well-documented sites of ethylene production/binding,
i.e., with endoplasmic reticulum, dictyosomes, mitochondria, plasma membrane, and tonoplast. During the sharp increase of ethylene
synthesis in mesophyll cells of rye leaves, the direct local continguity of chloroplast envelope or envelope protrusions with
the above mentioned cell compartments was typical. Moreover, a large number and diversity of versatile chloroplast-dictyosome
associations were conspicuous, in which both the chloroplast and each cisterna of dictyosome were capable to exo/endocytosis.
The dictyosomes were directed towards the chloroplasts, plasma membrane, or tonoplast both with cis-face, trans-face, or with
the rim, they could change their direction or shut up the trans-face, developing simultaneously several flexible chains of
vesicular dispatches among chloroplasts and some other cell compartments. This reflects interaction of protein/ethylene producing,
photosynthesising, DNA containing compartments, and regulated action of lysosomal system. Structural contacts and vesicular
transport among compartments of symplastic system equalises concentrations of H+, Ca2+, etc. ions, as well as provide connection with an apoplast. We propose that ethylene functions in plant mesophyll cells are both
as intra/intercellular signalling substance and as phytohormone that regulates gene expression in nuclei, chloroplasts, and
mitochondria in a complicated synapse-like process and causes programmed death of leaves of the main stalks of rye for the
sake of promoted growth of side shoots.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
Material and energy balances for fermentation processes with product formation are developed using regularities which are frequently useful in analyzing experimental results. Available electron balances are presented and used to analyze the results of experiments in which biomass and lysine are produced in batch culture using molasses and corn extract as organic substrates. Measured values of biomass productivity, lysine productivity, O2 consumption rate, heat evolution rate, CO2 evolution rate, and rate of utilization of reducing sugars (RS) are used to obtain estimates of biomass energetic yield, lysine energetic yield, and fraction of substrate energy evolved as heat. For two of the three experiments, based on the entire fermentation, the measured mass rate variables are very consistent and energy measurement errors are less than 10% when proper consideration is given to both the RS and the amino acids present in the organic substrate. The average measured value of 26.5 kcal/equivalent (equiv) of available electrons transferred to oxygen compares favorably with the known average value of 27 kcal/equiv. 相似文献
4.
Cristina Bosch Calero Elisabet Selga Ramon Brugada Fabiana S Scornik Guillermo J Pérez 《Channels (Austin, Tex.)》2014,8(1):95-102
Large-conductance Ca2+-activated (BK) channels, expressed in a variety of tissues, play a fundamental role in regulating and maintaining arterial tone. We recently demonstrated that the slow voltage indicator DiBAC4(3) does not depend, as initially proposed, on the β1 or β4 subunits to activate native arterial smooth muscle BK channels. Using recombinant mslo BK channels, we now show that the β1 subunit is not essential to this activation but exerts a large potentiating effect. DiBAC4(3) promotes concentration-dependent activation of BK channels and slows deactivation kinetics, changes that are independent of Ca2+. Kd values for BK channel activation by DiBAC4(3) in 0 mM Ca2+ are approximately 20 μM (α) and 5 μM (α+β1), and G-V curves shift up to −40mV and −110 mV, respectively. β1 to β2 mutations R11A and C18E do not interfere with the potentiating effect of the subunit. Our findings should help refine the role of the β1 subunit in cardiovascular pharmacology. 相似文献
5.
Permanent plastid-nuclear complexes (PNCs) exist in tobacco cells from their mitosis up to programmed cell death (PCD). PNCs in senescing cells of tobacco leaves were typical by enclosure of peroxisomes and mitochondria among chloroplasts which were in contact with nucleus. Such a complex position provides simultaneous interaction of these organelles and direct regulation of metabolism and PCD avoiding the cytosol. 相似文献
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A Novel Missense Mutation,I890T,in the Pore Region of Cardiac Sodium Channel Causes Brugada Syndrome
Anna Tarradas Elisabet Selga Pedro Beltran-Alvarez Alexandra Pérez-Serra Helena Riuró Ferran Picó Anna Iglesias Oscar Campuzano Víctor Castro-Urda Ignacio Fernández-Lozano Guillermo J. Pérez Fabiana S. Scornik Ramon Brugada 《PloS one》2013,8(1)
Brugada syndrome (BrS) is a life-threatening, inherited arrhythmogenic syndrome associated with autosomal dominant mutations in SCN5A, the gene encoding the cardiac Na+ channel alpha subunit (Nav1.5). The aim of this work was to characterize the functional alterations caused by a novel SCN5A mutation, I890T, and thus establish whether this mutation is associated with BrS. The mutation was identified by direct sequencing of SCN5A from the proband’s DNA. Wild-type (WT) or I890T Nav1.5 channels were heterologously expressed in human embryonic kidney cells. Sodium currents were studied using standard whole cell patch-clamp protocols and immunodetection experiments were performed using an antibody against human Nav1.5 channel. A marked decrease in current density was observed in cells expressing the I890T channel (from −52.0±6.5 pA/pF, n = 15 to −35.9±3.4 pA/pF, n = 22, at −20 mV, WT and I890T, respectively). Moreover, a positive shift of the activation curve was identified (V
1/2 = −32.0±0.3 mV, n = 18, and −27.3±0.3 mV, n = 22, WT and I890T, respectively). No changes between WT and I890T currents were observed in steady-state inactivation, time course of inactivation, slow inactivation or recovery from inactivation parameters. Cell surface protein biotinylation analyses confirmed that Nav1.5 channel membrane expression levels were similar in WT and I890T cells. In summary, our data reveal that the I890T mutation, located within the pore of Nav1.5, causes an evident loss-of-function of the channel. Thus, the BrS phenotype observed in the proband is most likely due to this mutation. 相似文献
8.
Elisabet Selga Alexandra Pérez-Serra Alba Moreno-Asso Seth Anderson Kristen Thomas Mayurika Desai Ramon Brugada Guillermo J Pérez Fabiana S Scornik 《Channels (Austin, Tex.)》2013,7(4):322-328
Large conductance calcium-activated potassium (BK) channels are widely expressed in the nervous system. We have recently shown that principal neurons from canine intracardiac ganglia (ICG) express a paxilline- and TEA-sensitive BK current, which increases neuronal excitability. In the present work, we further explore the molecular constituents of the BK current in canine ICG. We found that the β1 and β4 regulatory subunits are expressed in ICG. Single channel voltage-dependence at different calcium concentrations suggested that association of the BKα with a particular β subunit was not enough to explain the channel activity in this tissue. Indeed, we detected the presence of several splice variants of the BKα subunit. In conclusion, BK channels in canine ICG may result from the arrangement of different BKα splice variants, plus accessory β subunits. The particular combinations expressed in canine IC neurons likely rule the excitatory role of BK current in this tissue. 相似文献
9.
The role of plant mitochondria in the programmed cell death (PCD) is widely discussed. However, spectrum and sequence of mitochondrial structural changes during different types of PCD in leaves are poorly described. Pea, cucumber and rye plants were grown under controlled growing conditions. A part of them were sprinkled with ethylene releaser to accelerate cell death. During yellowing the palisade parenchyma mitochondria were attracted to nuclear envelope. Mitochondrial matrix became electron translucent. Mitochondria entered vacuole by invagination of tonoplast and formed multivesicular bodies. Ethephon treatment increased the frequency of sticking of mitochondria to the nuclear envelope or chloroplasts and peroxisomes. Mitochondria divided by different mechanisms and became enclosed in Golgi and ER derived authopagic vacuoles or in the central vacuole. Several fold increase of the diameter of cristae became typical. In all cases mitochondria were attached to nuclear envelope. It can be considered as structural mechanism of promoting of PCD. 相似文献
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