Marina Gavilanes-Ruíz - Academia.edu (original) (raw)

Papers by Marina Gavilanes-Ruíz

Research paper thumbnail of MPK6 Kinase Regulates Plasma Membrane H<sup>+</sup>-ATPase Activity in Cold Acclimation

Cold and freezing stresses severely affect plant growth, development, and survival rate. Some pla... more Cold and freezing stresses severely affect plant growth, development, and survival rate. Some plant species have evolved a process known as cold acclimation, in which plants exposed to temperatures above 0 °C trigger biochemical and physiological changes to survive freezing. During this response, several signaling events are mediated by transducers, such as mitogen activated protein kinase (MAPK) cascades. Plasma membrane H<sup>+</sup>-ATPase is a key enzyme for the plant cell life under regular and stress conditions. Using wild type and <i>mpk3</i> and <i>mpk6</i> knock out mutants in <i>Arabidopsis thaliana</i>, we explored the transcriptional, translational, and 14-3-3 protein regulation of the plasma membrane H<sup>+</sup>-ATPase activity under the acclimation process. The kinetic analysis revealed a differential profiling of the H<sup>+</sup>-ATPase activity depending on the presence or absence of MPK3 or MPK6 under non-acclimated or acclimated conditions. Negative regulation of the plasma membrane H<sup>+</sup>-ATPase activity was found to be exerted by MPK3 in non-acclimated conditions and by MPK6 in acclimated conditions, describing a novel form of regulation of this master ATPase. The MPK6 regulation involved changes in plasma membrane fluidity. Moreover, our results indicated that MPK6 is a critical regulator in the process of cold acclimation that leads to freezing tolerance and further survival.

Research paper thumbnail of The Protective Effect of Trichoderma asperellum on Tomato Plants against Fusarium oxysporum and Botrytis cinerea Diseases Involves Inhibition of Reactive Oxygen Species Production

International Journal of Molecular Sciences, 2019

Trichoderma species are fungi widely employed as plant-growth-promoting agents and for biological... more Trichoderma species are fungi widely employed as plant-growth-promoting agents and for biological control. Several commercial and laboratory-made solid formulations for mass production of Trichoderma have been reported. In this study, we evaluated a solid kaolin-based formulation to promote the absortion/retention of Trichoderma asperellum in the substrate for growing tomato plants. The unique implementation of this solid formulation resulted in an increased growth of the tomato plants, both in roots and shoots after 40 days of its application. Plants were challenged with two fungal pathogens, Fusarium oxysporum and Botrytis cinerea, and pretreatment with T. asperellum resulted in less severe wilting and stunting symptoms than non-treated plants. Treatment with T. asperellum formulation inhibited Reactive Oxygen Species (ROS) production in response to the pathogens in comparison to plants that were only challenged with both pathogens. These results suggest that decrease in ROS level...

Research paper thumbnail of Tonoplast and plasma membrane ATPases from maize lines of high or low vigour

Seed Science Research, 1992

The effectiveness of ATPase in germinated seed may play an important role in the vigour of germin... more The effectiveness of ATPase in germinated seed may play an important role in the vigour of germination. The activities of tonoplast and plasma membrane ATPases in two maize (Zea mays L.) lines with different vigour of germination were determined. ATP hydrolysis was measured in microsomal fractions from coleoptiles along with the responses to specific inhibitors for the plasma membrane, tonoplast and mitochondrial ATPases as well as for acid phosphatase. Nitrate-sensitive ATPase activity was 1.5–3.0 times lower in the low-vigour line than in the high-vigour line. Kinetic analysis of ATP hydrolysis at different substrate concentrations revealed the existence of two enzymes in the microsomal fractions of the two lines. The Vmax of enzyme 1 in the low-vigour line was a third of that in the high-vigour line. This enzyme was identified as the nitrate-sensitive or tonoplast ATPase on the basis of measurements of ATP hydrolysis in the presence of specific inhibitors at high (8.12mm) and low...

Research paper thumbnail of Comparison of plasma membrane H+-ATPase activity in vesicles obtained from dry and hydrated maize embryos

Biochimica et Biophysica Acta (BBA) - Biomembranes, 1998

Research paper thumbnail of MPK6 Kinase Regulates Plasma Membrane H+-ATPase Activity in Cold Acclimation

International Journal of Molecular Sciences, 2021

Cold and freezing stresses severely affect plant growth, development, and survival rate. Some pla... more Cold and freezing stresses severely affect plant growth, development, and survival rate. Some plant species have evolved a process known as cold acclimation, in which plants exposed to temperatures above 0 °C trigger biochemical and physiological changes to survive freezing. During this response, several signaling events are mediated by transducers, such as mitogen activated protein kinase (MAPK) cascades. Plasma membrane H+-ATPase is a key enzyme for the plant cell life under regular and stress conditions. Using wild type and mpk3 and mpk6 knock out mutants in Arabidopsis thaliana, we explored the transcriptional, translational, and 14-3-3 protein regulation of the plasma membrane H+-ATPase activity under the acclimation process. The kinetic analysis revealed a differential profiling of the H+-ATPase activity depending on the presence or absence of MPK3 or MPK6 under non-acclimated or acclimated conditions. Negative regulation of the plasma membrane H+-ATPase activity was found to ...

Research paper thumbnail of Importancia agrobiotecnológica de la enzima ACC desaminasa en rizobacterias, una revisión

Revista Fitotecnia Mexicana, Sep 1, 2013

Research paper thumbnail of Effect of 1-(p-methoxybenzyl)-6,7-methylenedioxyisoquinoline on mitochondrial respiration

1. Biochem Pharmacol. 1978 May 15;27(10):1505-7. Effect of 1-(p-methoxybenzyl)-6, 7-methylenediox... more 1. Biochem Pharmacol. 1978 May 15;27(10):1505-7. Effect of 1-(p-methoxybenzyl)-6, 7-methylenedioxyisoquinoline on mitochondrial respiration. de Meirelles NC, Meirelles UM, Gavilanes M, Tuena de Gómez-Puyou M, Gómez-Puyou A. ...

Research paper thumbnail of Effects of MPK3 and MPK6 kinases on the chloroplast architecture and function induced by cold acclimation in Arabidopsis

Photosynthesis Research, 2021

Exposure to low, non-freezing temperatures develops freezing tolerance in many plant species. Suc... more Exposure to low, non-freezing temperatures develops freezing tolerance in many plant species. Such process is called cold acclimation. Molecular changes undergone during cold acclimation are orchestrated by signalling networks including MAP kinases. Structure and function of chloroplasts are affected by low temperatures. The aim of this work was to study how the MAP kinases MPK3 and MPK6 are involved in the chloroplast performance upon a long period of cold acclimation. We used Arabidopsis thaliana wild type and mpk3 and mpk6 mutants. Adult plants were acclimated during 7 days at 4 °C and then measurements of PSII performance and chloroplast ultrastructure were carried out. Only the mpk6 acclimated plants showed a high freezing sensitivity. No differences in the PSII function were observed in the plants from the three genotypes exposed to non-acclimated or acclimated conditions. The acclimation of wild-type plants produced severe alterations in the ultrastructure of chloroplast and ...

Research paper thumbnail of Plasma Membrane Fluidity: An Environment Thermal Detector in Plants

Cells

The lipid matrix in cell membranes is a dynamic, bidimensional array of amphipathic molecules exh... more The lipid matrix in cell membranes is a dynamic, bidimensional array of amphipathic molecules exhibiting mesomorphism, which contributes to the membrane fluidity changes in response to temperature fluctuation. As sessile organisms, plants must rapidly and accurately respond to environmental thermal variations. However, mechanisms underlying temperature perception in plants are poorly understood. We studied the thermal plasticity of membrane fluidity using three fluorescent probes across a temperature range of −5 to 41 °C in isolated microsomal fraction (MF), vacuolar membrane (VM), and plasma membrane (PM) vesicles from Arabidopsis plants. Results showed that PM were highly fluid and exhibited more phase transitions and hysteresis, while VM and MF lacked such attributes. These findings suggest that PM is an important cell hub with the capacity to rapidly undergo fluidity modifications in response to small changes of temperatures in ranges spanning those experienced in natural habita...

Research paper thumbnail of Tonoplast and plasma membrane ATPases from maize lines of high or low vigour

Seed Science Research, 1992

The effectiveness of ATPase in germinated seed may play an important role in the vigour of germin... more The effectiveness of ATPase in germinated seed may play an important role in the vigour of germination. The activities of tonoplast and plasma membrane ATPases in two maize (Zea mays L.) lines with different vigour of germination were determined. ATP hydrolysis was measured in microsomal fractions from coleoptiles along with the responses to specific inhibitors for the plasma membrane, tonoplast and mitochondrial ATPases as well as for acid phosphatase. Nitrate-sensitive ATPase activity was 1.5–3.0 times lower in the low-vigour line than in the high-vigour line. Kinetic analysis of ATP hydrolysis at different substrate concentrations revealed the existence of two enzymes in the microsomal fractions of the two lines. The Vmax of enzyme 1 in the low-vigour line was a third of that in the high-vigour line. This enzyme was identified as the nitrate-sensitive or tonoplast ATPase on the basis of measurements of ATP hydrolysis in the presence of specific inhibitors at high (8.12mm) and low (0.77mm) ATP concentrations.

Research paper thumbnail of Long-chain bases, phosphatidic acid, MAPKs, and reactive oxygen species as nodal signal transducers in stress responses in Arabidopsis

Frontiers in Plant Science, 2015

Due to their sessile condition, plants have developed sensitive, fast, and effective ways to cont... more Due to their sessile condition, plants have developed sensitive, fast, and effective ways to contend with environmental changes. These mechanisms operate as informational wires conforming extensive and intricate networks that are connected in several points. The responses are designed as pathways orchestrated by molecules that are transducers of protein and non-protein nature. Their chemical nature imposes selective features such as specificity, formation rate, and generation site to the informational routes. Enzymes such as mitogen-activated protein kinases and non-protein, smaller molecules, such as longchain bases, phosphatidic acid, and reactive oxygen species are recurrent transducers in the pleiotropic responses to biotic and abiotic stresses in plants. In this review, we considered these four components as nodal points of converging signaling pathways that start from very diverse stimuli and evoke very different responses. These pleiotropic effects may be explained by the potentiality that every one of these four mediators can be expressed from different sources, cellular location, temporality, or magnitude. Here, we review recent advances in our understanding of the interplay of these four specific signaling components in Arabidopsis cells, with an emphasis on drought, cold and pathogen stresses.

Research paper thumbnail of Purification of plasma membranes from dry maize embryos

Physiologia Plantarum, 1997

... Additional Information. How to Cite. Sánchez-Nieto, S., García-Rubio, O., Pacheco-Moisés, F.,... more ... Additional Information. How to Cite. Sánchez-Nieto, S., García-Rubio, O., Pacheco-Moisés, F., Carballo, A., Rodríguez-Sotres, R. and Gavilanes-Ruíz, M. (1997), Purification of plasma membranes from dry maize embryos. ... 135–146. Ellis Harwood, Chichester , London . ...

Research paper thumbnail of Comparison of plasma membrane H+-ATPase activity in vesicles obtained from dry and hydrated maize embryos

Biochimica et Biophysica Acta (BBA) - Biomembranes, 1998

ATP hydrolysis from H+-ATPase of plasma membrane was measured in vesicles from maize embryos imbi... more ATP hydrolysis from H+-ATPase of plasma membrane was measured in vesicles from maize embryos imbibed at times between 0 and 5 h. The activity had a maximum at 2 h of imbibition. In order to detect whether the enzyme had the same characteristics through the first 5 h of imbibition, vanadate and lysophophatydilcholine sensitivities, as well as trypsin, pH and temperature effects on the activity of the H +-ATPase from plasma membrane vesicles isolated from embryos imbibed at 0 or 5 h were studied. The results indicate that the activity expressed at 0 h is very different from the activity at 5 h. The activity from embryos imbibed for 5 h was less sensitive to vanadate, trypsin and lysophosphatidylcholine, more sensitive to denaturing temperatures and with a broader pH dependence, as compared to the activity from embryos that were not imbibed. When vanadate-sensitive ATPase activity was purified by anion exchange chromatography, the peaks obtained from the 0 and 5 h imbibed embryos were different and non-overlapping. These data could be interpreted in terms of different enzyme structures from dry and imbibed embryos due to either different primary structures or covalent modifications, or differences in membrane vicinities.

Research paper thumbnail of Arabidopsis mutants in sphingolipid synthesis as tools to understand the structure and function of membrane microdomains in plasmodesmata

Frontiers in Plant Science, 2014

Plasmodesmata-intercellular channels that communicate adjacent cells-possess complex membranous s... more Plasmodesmata-intercellular channels that communicate adjacent cells-possess complex membranous structures. Recent evidences indicate that plasmodesmata contain membrane microdomains. In order to understand how these submembrane regions collaborate to plasmodesmata function, it is necessary to characterize their size, composition and dynamics. An approach that can shed light on these microdomain features is based on the use of Arabidopsis mutants in sphingolipid synthesis. Sphingolipids are canonical components of microdomains together with sterols and some glycerolipids. Moreover, sphingolipids are transducers in pathways that display programmed cell death as a defense mechanism against pathogens. The study of Arabidopsis mutants would allow determining which structural features of the sphingolipids are important for the formation and stability of microdomains, and if defense signaling networks using sphingoid bases as second messengers are associated to plasmodesmata operation. Such studies need to be complemented by analysis of the ultrastructure and the use of protein probes for plasmodesmata microdomains and may constitute a very valuable source of information to analyze these membrane structures.

Research paper thumbnail of Fatty acid profiles from the plasma membrane and detergent resistant membranes of two plant species

Phytochemistry, 2015

It is essential to establish the composition of the plant plasma membrane in order to understand ... more It is essential to establish the composition of the plant plasma membrane in order to understand its organization and behavior under continually changing environments. Knowledge of the lipid phase, in particular the fatty acid (FA) complex repertoire, is important since FAs determine many of the physical-chemical membrane properties. FAs are constituents of the membrane glycerolipid and sphingolipid backbones and can also be linked to some sterols. In addition, FAs are components of complex lipids that can constitute membrane micro-domains, and the use of detergent-resistant membranes is a common approach to study their composition. The diversity and cellular allocation of the membrane lipids containing FAs are very diverse and the approaches to analyze them provide only general information. In this work, a detailed FA analysis was performed using highly purified plasma membranes from bean leaves and germinating maize embryos and their respective detergent-resistant membrane preparations. The analyses showed the presence of a significant amount of very long chain FAs (containing 28C, 30C and 32C), in both plasma membrane preparations from bean and maize, that have not been previously reported. Herein is demonstrated that a significant enrichment of very long chain saturated FAs and saturated FAs can occur in detergent-resistant membrane preparations, as compared to the plasma membranes from both plant species. Considering that a thorough analysis of FAs is rarely performed in purified plasma membranes and detergent-resistant membranes, this work provides qualitative and quantitative evidence on the contributions of the length and saturation of FAs to the organization of the plant plasma membrane and detergent-resistant membranes.

Research paper thumbnail of Plant lipid environment and membrane enzymes: the case of the plasma membrane H+-ATPase

Plant Cell Reports, 2015

Several lipid classes constitute the universal matrix of the biological membranes. With their amp... more Several lipid classes constitute the universal matrix of the biological membranes. With their amphipathic nature, lipids not only build the continuous barrier that confers identity to every cell and organelle, but they are also active actors that modulate the activity of the proteins immersed in the lipid bilayer. The plasma membrane H(+)-ATPase, an enzyme from plant cells, is an excellent example of a transmembrane protein whose activity is influenced by the hydrophilic compartments at both sides of the membrane and by the hydrophobic domains of the lipid bilayer. As a result, an extensive documentation of the effect of numerous amphiphiles in the enzyme activity can be found. Detergents, membrane glycerolipids, and sterols can produce activation or inhibition of the enzyme activity. In some cases, these effects are associated with the lipids of the membrane bulk, but in others, a direct interaction of the lipid with the protein is involved. This review gives an account of reports related to the action of the membrane lipids on the H(+)-ATPase activity.

Research paper thumbnail of Plant Sphingolipids: Structure, Synthesis and Function

Advances in Photosynthesis and Respiration, 2009

Research paper thumbnail of Fumonisin B1, a sphingoid toxin, is a potent inhibitor of the plasma membrane H+-ATPase

Planta, 2005

Fumonisin B 1 (FB 1 ) is an amphipathic toxin produced by the pathogenic fungus Fusarium verticil... more Fumonisin B 1 (FB 1 ) is an amphipathic toxin produced by the pathogenic fungus Fusarium verticillioides which causes stem, root and ear rot in maize (Zea mays L.). In this work, we studied the action of FB 1 on the plasma membrane H + -ATPase (EC 3.6.1.34) from germinating maize embryos, and on the fluidity and lipid peroxidation of these membranes. In maize embryos the toxin at 40 lM inhibited root elongation by 50% and at 30 lM decreased medium acidification by about 80%. Irrespective of the presence and absence of FB 1 , the H + -ATPase in plasma membrane vesicles exhibited nonhyperbolic saturation kinetics by ATPH-Mg, with Hill number of 0.67. Initial velocity studies revealed that FB 1 is a total uncompetitive inhibitor of this enzyme with an inhibition constant value of 17.5±1 lM. Thus FB 1 decreased V max and increased the apparent affinity of the enzyme for ATP-Mg to the same extent. Although FB 1 increased the fluidity at the hydrophobic region of the membrane, no correlation was found with its effect on enzyme activity, since both effects showed different FB 1concentration dependence. Peroxidation of membrane lipids was not affected by the toxin. Our results suggest that, under in vivo conditions, the plasma membrane H + -ATPase is a potentially important target of the toxin, as it is inhibited not only by FB 1 but also by its structural analogs, the sphingoid intermediates, which accumulate upon the inhibition of sphinganine N-acyltransferase by this toxin.

Research paper thumbnail of Reactive oxygen species as transducers of sphinganine-mediated cell death pathway

Plant Signaling & Behavior, 2011

Research paper thumbnail of The plasma membrane H+-ATPase of maize embryos localizes in regions that are critical during the onset of germination

Plant Science, 2005

The H + -ATPase is a plasma membrane enzyme that hydrolyzes ATP and translocates protons from the... more The H + -ATPase is a plasma membrane enzyme that hydrolyzes ATP and translocates protons from the cytosol to the apoplast space. The resulting acidification is used to promote stomata opening, pH homeostasis, secondary transport of nutrients, and cell elongation. The latter two processes are critical in germination, since radicle protrusion, requires the growth of embryo cells. Earlier studies have shown that the plasma membrane H + -ATPase is already active during the first hours of imbibition. Here, the localization of this enzyme was studied in maize embryos by histochemical and immunochemical techniques at 2 h of imbibition. The enzyme is mainly located in regions of the embryo that require high transport activity or that participate in cell elongation: the scutellum, the root and the plumule. The cells that were more immunolabeled were those located in the epidermis, in the parenchyma and in the elements of the vascular bundles. These results suggest that the plasma membrane H + -ATPase levels present in the first hours of imbibition are preserved and/or are newly synthesized to fulfill the demands of transport and elongation of the embryo on the onset of seed germination. #

Research paper thumbnail of MPK6 Kinase Regulates Plasma Membrane H<sup>+</sup>-ATPase Activity in Cold Acclimation

Cold and freezing stresses severely affect plant growth, development, and survival rate. Some pla... more Cold and freezing stresses severely affect plant growth, development, and survival rate. Some plant species have evolved a process known as cold acclimation, in which plants exposed to temperatures above 0 °C trigger biochemical and physiological changes to survive freezing. During this response, several signaling events are mediated by transducers, such as mitogen activated protein kinase (MAPK) cascades. Plasma membrane H<sup>+</sup>-ATPase is a key enzyme for the plant cell life under regular and stress conditions. Using wild type and <i>mpk3</i> and <i>mpk6</i> knock out mutants in <i>Arabidopsis thaliana</i>, we explored the transcriptional, translational, and 14-3-3 protein regulation of the plasma membrane H<sup>+</sup>-ATPase activity under the acclimation process. The kinetic analysis revealed a differential profiling of the H<sup>+</sup>-ATPase activity depending on the presence or absence of MPK3 or MPK6 under non-acclimated or acclimated conditions. Negative regulation of the plasma membrane H<sup>+</sup>-ATPase activity was found to be exerted by MPK3 in non-acclimated conditions and by MPK6 in acclimated conditions, describing a novel form of regulation of this master ATPase. The MPK6 regulation involved changes in plasma membrane fluidity. Moreover, our results indicated that MPK6 is a critical regulator in the process of cold acclimation that leads to freezing tolerance and further survival.

Research paper thumbnail of The Protective Effect of Trichoderma asperellum on Tomato Plants against Fusarium oxysporum and Botrytis cinerea Diseases Involves Inhibition of Reactive Oxygen Species Production

International Journal of Molecular Sciences, 2019

Trichoderma species are fungi widely employed as plant-growth-promoting agents and for biological... more Trichoderma species are fungi widely employed as plant-growth-promoting agents and for biological control. Several commercial and laboratory-made solid formulations for mass production of Trichoderma have been reported. In this study, we evaluated a solid kaolin-based formulation to promote the absortion/retention of Trichoderma asperellum in the substrate for growing tomato plants. The unique implementation of this solid formulation resulted in an increased growth of the tomato plants, both in roots and shoots after 40 days of its application. Plants were challenged with two fungal pathogens, Fusarium oxysporum and Botrytis cinerea, and pretreatment with T. asperellum resulted in less severe wilting and stunting symptoms than non-treated plants. Treatment with T. asperellum formulation inhibited Reactive Oxygen Species (ROS) production in response to the pathogens in comparison to plants that were only challenged with both pathogens. These results suggest that decrease in ROS level...

Research paper thumbnail of Tonoplast and plasma membrane ATPases from maize lines of high or low vigour

Seed Science Research, 1992

The effectiveness of ATPase in germinated seed may play an important role in the vigour of germin... more The effectiveness of ATPase in germinated seed may play an important role in the vigour of germination. The activities of tonoplast and plasma membrane ATPases in two maize (Zea mays L.) lines with different vigour of germination were determined. ATP hydrolysis was measured in microsomal fractions from coleoptiles along with the responses to specific inhibitors for the plasma membrane, tonoplast and mitochondrial ATPases as well as for acid phosphatase. Nitrate-sensitive ATPase activity was 1.5–3.0 times lower in the low-vigour line than in the high-vigour line. Kinetic analysis of ATP hydrolysis at different substrate concentrations revealed the existence of two enzymes in the microsomal fractions of the two lines. The Vmax of enzyme 1 in the low-vigour line was a third of that in the high-vigour line. This enzyme was identified as the nitrate-sensitive or tonoplast ATPase on the basis of measurements of ATP hydrolysis in the presence of specific inhibitors at high (8.12mm) and low...

Research paper thumbnail of Comparison of plasma membrane H+-ATPase activity in vesicles obtained from dry and hydrated maize embryos

Biochimica et Biophysica Acta (BBA) - Biomembranes, 1998

Research paper thumbnail of MPK6 Kinase Regulates Plasma Membrane H+-ATPase Activity in Cold Acclimation

International Journal of Molecular Sciences, 2021

Cold and freezing stresses severely affect plant growth, development, and survival rate. Some pla... more Cold and freezing stresses severely affect plant growth, development, and survival rate. Some plant species have evolved a process known as cold acclimation, in which plants exposed to temperatures above 0 °C trigger biochemical and physiological changes to survive freezing. During this response, several signaling events are mediated by transducers, such as mitogen activated protein kinase (MAPK) cascades. Plasma membrane H+-ATPase is a key enzyme for the plant cell life under regular and stress conditions. Using wild type and mpk3 and mpk6 knock out mutants in Arabidopsis thaliana, we explored the transcriptional, translational, and 14-3-3 protein regulation of the plasma membrane H+-ATPase activity under the acclimation process. The kinetic analysis revealed a differential profiling of the H+-ATPase activity depending on the presence or absence of MPK3 or MPK6 under non-acclimated or acclimated conditions. Negative regulation of the plasma membrane H+-ATPase activity was found to ...

Research paper thumbnail of Importancia agrobiotecnológica de la enzima ACC desaminasa en rizobacterias, una revisión

Revista Fitotecnia Mexicana, Sep 1, 2013

Research paper thumbnail of Effect of 1-(p-methoxybenzyl)-6,7-methylenedioxyisoquinoline on mitochondrial respiration

1. Biochem Pharmacol. 1978 May 15;27(10):1505-7. Effect of 1-(p-methoxybenzyl)-6, 7-methylenediox... more 1. Biochem Pharmacol. 1978 May 15;27(10):1505-7. Effect of 1-(p-methoxybenzyl)-6, 7-methylenedioxyisoquinoline on mitochondrial respiration. de Meirelles NC, Meirelles UM, Gavilanes M, Tuena de Gómez-Puyou M, Gómez-Puyou A. ...

Research paper thumbnail of Effects of MPK3 and MPK6 kinases on the chloroplast architecture and function induced by cold acclimation in Arabidopsis

Photosynthesis Research, 2021

Exposure to low, non-freezing temperatures develops freezing tolerance in many plant species. Suc... more Exposure to low, non-freezing temperatures develops freezing tolerance in many plant species. Such process is called cold acclimation. Molecular changes undergone during cold acclimation are orchestrated by signalling networks including MAP kinases. Structure and function of chloroplasts are affected by low temperatures. The aim of this work was to study how the MAP kinases MPK3 and MPK6 are involved in the chloroplast performance upon a long period of cold acclimation. We used Arabidopsis thaliana wild type and mpk3 and mpk6 mutants. Adult plants were acclimated during 7 days at 4 °C and then measurements of PSII performance and chloroplast ultrastructure were carried out. Only the mpk6 acclimated plants showed a high freezing sensitivity. No differences in the PSII function were observed in the plants from the three genotypes exposed to non-acclimated or acclimated conditions. The acclimation of wild-type plants produced severe alterations in the ultrastructure of chloroplast and ...

Research paper thumbnail of Plasma Membrane Fluidity: An Environment Thermal Detector in Plants

Cells

The lipid matrix in cell membranes is a dynamic, bidimensional array of amphipathic molecules exh... more The lipid matrix in cell membranes is a dynamic, bidimensional array of amphipathic molecules exhibiting mesomorphism, which contributes to the membrane fluidity changes in response to temperature fluctuation. As sessile organisms, plants must rapidly and accurately respond to environmental thermal variations. However, mechanisms underlying temperature perception in plants are poorly understood. We studied the thermal plasticity of membrane fluidity using three fluorescent probes across a temperature range of −5 to 41 °C in isolated microsomal fraction (MF), vacuolar membrane (VM), and plasma membrane (PM) vesicles from Arabidopsis plants. Results showed that PM were highly fluid and exhibited more phase transitions and hysteresis, while VM and MF lacked such attributes. These findings suggest that PM is an important cell hub with the capacity to rapidly undergo fluidity modifications in response to small changes of temperatures in ranges spanning those experienced in natural habita...

Research paper thumbnail of Tonoplast and plasma membrane ATPases from maize lines of high or low vigour

Seed Science Research, 1992

The effectiveness of ATPase in germinated seed may play an important role in the vigour of germin... more The effectiveness of ATPase in germinated seed may play an important role in the vigour of germination. The activities of tonoplast and plasma membrane ATPases in two maize (Zea mays L.) lines with different vigour of germination were determined. ATP hydrolysis was measured in microsomal fractions from coleoptiles along with the responses to specific inhibitors for the plasma membrane, tonoplast and mitochondrial ATPases as well as for acid phosphatase. Nitrate-sensitive ATPase activity was 1.5–3.0 times lower in the low-vigour line than in the high-vigour line. Kinetic analysis of ATP hydrolysis at different substrate concentrations revealed the existence of two enzymes in the microsomal fractions of the two lines. The Vmax of enzyme 1 in the low-vigour line was a third of that in the high-vigour line. This enzyme was identified as the nitrate-sensitive or tonoplast ATPase on the basis of measurements of ATP hydrolysis in the presence of specific inhibitors at high (8.12mm) and low (0.77mm) ATP concentrations.

Research paper thumbnail of Long-chain bases, phosphatidic acid, MAPKs, and reactive oxygen species as nodal signal transducers in stress responses in Arabidopsis

Frontiers in Plant Science, 2015

Due to their sessile condition, plants have developed sensitive, fast, and effective ways to cont... more Due to their sessile condition, plants have developed sensitive, fast, and effective ways to contend with environmental changes. These mechanisms operate as informational wires conforming extensive and intricate networks that are connected in several points. The responses are designed as pathways orchestrated by molecules that are transducers of protein and non-protein nature. Their chemical nature imposes selective features such as specificity, formation rate, and generation site to the informational routes. Enzymes such as mitogen-activated protein kinases and non-protein, smaller molecules, such as longchain bases, phosphatidic acid, and reactive oxygen species are recurrent transducers in the pleiotropic responses to biotic and abiotic stresses in plants. In this review, we considered these four components as nodal points of converging signaling pathways that start from very diverse stimuli and evoke very different responses. These pleiotropic effects may be explained by the potentiality that every one of these four mediators can be expressed from different sources, cellular location, temporality, or magnitude. Here, we review recent advances in our understanding of the interplay of these four specific signaling components in Arabidopsis cells, with an emphasis on drought, cold and pathogen stresses.

Research paper thumbnail of Purification of plasma membranes from dry maize embryos

Physiologia Plantarum, 1997

... Additional Information. How to Cite. Sánchez-Nieto, S., García-Rubio, O., Pacheco-Moisés, F.,... more ... Additional Information. How to Cite. Sánchez-Nieto, S., García-Rubio, O., Pacheco-Moisés, F., Carballo, A., Rodríguez-Sotres, R. and Gavilanes-Ruíz, M. (1997), Purification of plasma membranes from dry maize embryos. ... 135–146. Ellis Harwood, Chichester , London . ...

Research paper thumbnail of Comparison of plasma membrane H+-ATPase activity in vesicles obtained from dry and hydrated maize embryos

Biochimica et Biophysica Acta (BBA) - Biomembranes, 1998

ATP hydrolysis from H+-ATPase of plasma membrane was measured in vesicles from maize embryos imbi... more ATP hydrolysis from H+-ATPase of plasma membrane was measured in vesicles from maize embryos imbibed at times between 0 and 5 h. The activity had a maximum at 2 h of imbibition. In order to detect whether the enzyme had the same characteristics through the first 5 h of imbibition, vanadate and lysophophatydilcholine sensitivities, as well as trypsin, pH and temperature effects on the activity of the H +-ATPase from plasma membrane vesicles isolated from embryos imbibed at 0 or 5 h were studied. The results indicate that the activity expressed at 0 h is very different from the activity at 5 h. The activity from embryos imbibed for 5 h was less sensitive to vanadate, trypsin and lysophosphatidylcholine, more sensitive to denaturing temperatures and with a broader pH dependence, as compared to the activity from embryos that were not imbibed. When vanadate-sensitive ATPase activity was purified by anion exchange chromatography, the peaks obtained from the 0 and 5 h imbibed embryos were different and non-overlapping. These data could be interpreted in terms of different enzyme structures from dry and imbibed embryos due to either different primary structures or covalent modifications, or differences in membrane vicinities.

Research paper thumbnail of Arabidopsis mutants in sphingolipid synthesis as tools to understand the structure and function of membrane microdomains in plasmodesmata

Frontiers in Plant Science, 2014

Plasmodesmata-intercellular channels that communicate adjacent cells-possess complex membranous s... more Plasmodesmata-intercellular channels that communicate adjacent cells-possess complex membranous structures. Recent evidences indicate that plasmodesmata contain membrane microdomains. In order to understand how these submembrane regions collaborate to plasmodesmata function, it is necessary to characterize their size, composition and dynamics. An approach that can shed light on these microdomain features is based on the use of Arabidopsis mutants in sphingolipid synthesis. Sphingolipids are canonical components of microdomains together with sterols and some glycerolipids. Moreover, sphingolipids are transducers in pathways that display programmed cell death as a defense mechanism against pathogens. The study of Arabidopsis mutants would allow determining which structural features of the sphingolipids are important for the formation and stability of microdomains, and if defense signaling networks using sphingoid bases as second messengers are associated to plasmodesmata operation. Such studies need to be complemented by analysis of the ultrastructure and the use of protein probes for plasmodesmata microdomains and may constitute a very valuable source of information to analyze these membrane structures.

Research paper thumbnail of Fatty acid profiles from the plasma membrane and detergent resistant membranes of two plant species

Phytochemistry, 2015

It is essential to establish the composition of the plant plasma membrane in order to understand ... more It is essential to establish the composition of the plant plasma membrane in order to understand its organization and behavior under continually changing environments. Knowledge of the lipid phase, in particular the fatty acid (FA) complex repertoire, is important since FAs determine many of the physical-chemical membrane properties. FAs are constituents of the membrane glycerolipid and sphingolipid backbones and can also be linked to some sterols. In addition, FAs are components of complex lipids that can constitute membrane micro-domains, and the use of detergent-resistant membranes is a common approach to study their composition. The diversity and cellular allocation of the membrane lipids containing FAs are very diverse and the approaches to analyze them provide only general information. In this work, a detailed FA analysis was performed using highly purified plasma membranes from bean leaves and germinating maize embryos and their respective detergent-resistant membrane preparations. The analyses showed the presence of a significant amount of very long chain FAs (containing 28C, 30C and 32C), in both plasma membrane preparations from bean and maize, that have not been previously reported. Herein is demonstrated that a significant enrichment of very long chain saturated FAs and saturated FAs can occur in detergent-resistant membrane preparations, as compared to the plasma membranes from both plant species. Considering that a thorough analysis of FAs is rarely performed in purified plasma membranes and detergent-resistant membranes, this work provides qualitative and quantitative evidence on the contributions of the length and saturation of FAs to the organization of the plant plasma membrane and detergent-resistant membranes.

Research paper thumbnail of Plant lipid environment and membrane enzymes: the case of the plasma membrane H+-ATPase

Plant Cell Reports, 2015

Several lipid classes constitute the universal matrix of the biological membranes. With their amp... more Several lipid classes constitute the universal matrix of the biological membranes. With their amphipathic nature, lipids not only build the continuous barrier that confers identity to every cell and organelle, but they are also active actors that modulate the activity of the proteins immersed in the lipid bilayer. The plasma membrane H(+)-ATPase, an enzyme from plant cells, is an excellent example of a transmembrane protein whose activity is influenced by the hydrophilic compartments at both sides of the membrane and by the hydrophobic domains of the lipid bilayer. As a result, an extensive documentation of the effect of numerous amphiphiles in the enzyme activity can be found. Detergents, membrane glycerolipids, and sterols can produce activation or inhibition of the enzyme activity. In some cases, these effects are associated with the lipids of the membrane bulk, but in others, a direct interaction of the lipid with the protein is involved. This review gives an account of reports related to the action of the membrane lipids on the H(+)-ATPase activity.

Research paper thumbnail of Plant Sphingolipids: Structure, Synthesis and Function

Advances in Photosynthesis and Respiration, 2009

Research paper thumbnail of Fumonisin B1, a sphingoid toxin, is a potent inhibitor of the plasma membrane H+-ATPase

Planta, 2005

Fumonisin B 1 (FB 1 ) is an amphipathic toxin produced by the pathogenic fungus Fusarium verticil... more Fumonisin B 1 (FB 1 ) is an amphipathic toxin produced by the pathogenic fungus Fusarium verticillioides which causes stem, root and ear rot in maize (Zea mays L.). In this work, we studied the action of FB 1 on the plasma membrane H + -ATPase (EC 3.6.1.34) from germinating maize embryos, and on the fluidity and lipid peroxidation of these membranes. In maize embryos the toxin at 40 lM inhibited root elongation by 50% and at 30 lM decreased medium acidification by about 80%. Irrespective of the presence and absence of FB 1 , the H + -ATPase in plasma membrane vesicles exhibited nonhyperbolic saturation kinetics by ATPH-Mg, with Hill number of 0.67. Initial velocity studies revealed that FB 1 is a total uncompetitive inhibitor of this enzyme with an inhibition constant value of 17.5±1 lM. Thus FB 1 decreased V max and increased the apparent affinity of the enzyme for ATP-Mg to the same extent. Although FB 1 increased the fluidity at the hydrophobic region of the membrane, no correlation was found with its effect on enzyme activity, since both effects showed different FB 1concentration dependence. Peroxidation of membrane lipids was not affected by the toxin. Our results suggest that, under in vivo conditions, the plasma membrane H + -ATPase is a potentially important target of the toxin, as it is inhibited not only by FB 1 but also by its structural analogs, the sphingoid intermediates, which accumulate upon the inhibition of sphinganine N-acyltransferase by this toxin.

Research paper thumbnail of Reactive oxygen species as transducers of sphinganine-mediated cell death pathway

Plant Signaling & Behavior, 2011

Research paper thumbnail of The plasma membrane H+-ATPase of maize embryos localizes in regions that are critical during the onset of germination

Plant Science, 2005

The H + -ATPase is a plasma membrane enzyme that hydrolyzes ATP and translocates protons from the... more The H + -ATPase is a plasma membrane enzyme that hydrolyzes ATP and translocates protons from the cytosol to the apoplast space. The resulting acidification is used to promote stomata opening, pH homeostasis, secondary transport of nutrients, and cell elongation. The latter two processes are critical in germination, since radicle protrusion, requires the growth of embryo cells. Earlier studies have shown that the plasma membrane H + -ATPase is already active during the first hours of imbibition. Here, the localization of this enzyme was studied in maize embryos by histochemical and immunochemical techniques at 2 h of imbibition. The enzyme is mainly located in regions of the embryo that require high transport activity or that participate in cell elongation: the scutellum, the root and the plumule. The cells that were more immunolabeled were those located in the epidermis, in the parenchyma and in the elements of the vascular bundles. These results suggest that the plasma membrane H + -ATPase levels present in the first hours of imbibition are preserved and/or are newly synthesized to fulfill the demands of transport and elongation of the embryo on the onset of seed germination. #