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Your search keyword '"Martínez-Trujillo, M. A."' showing total 16 results
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16 results on '"Martínez-Trujillo, M. A."'

5. An updated review on the modulation of carbon partitioning and allocation in arbuscular mycorrhizal plants

Author

Universidad Michoacana de San Nicolás de Hidalgo, Consejo Nacional de Ciencia y Tecnología (México), Salmerón-Santiago, I. A., Martínez-Trujillo, M., Valdez-Alarcón, J.J., Pedraza-Santos, M.E., Santoyo, G., Pozo Jiménez, María José, Chávez-Bárcenas, A.T., Universidad Michoacana de San Nicolás de Hidalgo, Consejo Nacional de Ciencia y Tecnología (México), Salmerón-Santiago, I. A., Martínez-Trujillo, M., Valdez-Alarcón, J.J., Pedraza-Santos, M.E., Santoyo, G., Pozo Jiménez, María José, and Chávez-Bárcenas, A.T.

Abstract

Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs that supply mineral nutrients to the host plant in exchange for carbon derived from photosynthesis. Sucrose is the end‐product of photosynthesis and the main compound used by plants to translocate photosynthates to non-photosynthetic tissues. AMF alter carbon distribution in plants by modifying the expression and activity of key enzymes of sucrose biosynthesis, transport, and/or catabolism. Since sucrose is essential for the maintenance of all metabolic and physiological processes, the modifications addressed by AMF can significantly affect plant development and stress responses. AMF also modulate plant lipid biosynthesis to acquire storage reserves, generate biomass, and fulfill its life cycle. In this review we address the most relevant aspects of the influence of AMF on sucrose and lipid metabolism in plants, including its effects on sucrose biosynthesis both in photosynthetic and heterotrophic tissues, and the influence of sucrose on lipid biosynthesis in the context of the symbiosis. We present a hypothetical model of carbon partitioning between plants and AMF in which the coordinated action of sucrose biosynthesis, transport, and catabolism plays a role in the generation of hexose gradients to supply carbon to AMF, and to control the amount of carbon assigned to the fungus.

Published
2022

8. Effect of particle size on mesophilic anaerobic digestion of thermally pre-treated waste activated sludge.

Author

Vigueras-Carmona, S. E., Martínez Trujillo, M. A., García Rivero, M., Membrillo Venegas, I., and Zafra Jiménez, G.

Subjects
*ACTIVATED sludge process, *PARTICLE size determination, *ANAEROBIC digestion, *SOLUBILIZATION, *METHANE
Abstract

The objective of this study was to demonstrate a significant difference in the rate of methane production when anaerobic digestion of sewage sludge is done using different particle sizes. To this end, several parameters were determined in thermally pre-treated waste activated sludge at different temperatures: floc disintegration energy, efficiency of solubilisation and production rate of methane. Energy disintegration was 3,232 kJ/kgTS, the best solubilisation efficiency (26%) was observed when the waste activated sludge was heated to 90°C. Particle sizes tested were 105, 74, 62, 53, 37, 16, 8, and 2.2 µm. The maximum methane production rate (0.21 kg CH4/m³/d) was obtained with the smallest particle size. There are significant differences between methane production rates particle sizes. [ABSTRACT FROM AUTHOR]

Published
2016

11. Role of arbuscular mycorrhizal fungi in the uptake of phosphorus by micropropagated blackberry (Rubus fruticosus var. brazos) plants.

Author

Velázquez, E., Rodríguez-Barrueco, C., Carreón-Abud, Y., Soriano-Bello, E., and Martínez-Trujillo, M.

Abstract

The beneficial effects of arbuscular mycorrhizae on plant growth have been often related to the increase in the uptake of no mobile nutrients from the soil such as phosphorus. In this work, the data obtained about the increase of phosphorus by plants extracted from in vitro cultures with mycorrhizae in relation with non-mycorrhizal plants is shown. The mycorrhizal fungi were isolated and propagated from maize cultures. Micro propagation systems for blackberry were used in the Murashige and Skoog medium, varying the hormone concentration according to the growth. Once the plants were developed, they were transplanted into sterile soil and were inoculated with the previously propagated mycorrhizal fungi and finally transferred to a greenhouse. Harvest was made periodically with the objective of making the evaluation of the different agronomic variables and the amount of phosphorus in the aerial parts of the plant was determined by the colorimetric method of blue molybdate. The percent of phosphorus in the aerial part of Rubus fruticosus var. brazos, started to increase since the 30 days of treatment, until it increased an 80% at the end of the assay. This brought more efficiency in the mycorrhized plants to raise the photosynthetic rates in a shorter period of time and to be under a lower stress due to the transplanting process. One of the major effects of mycorrhizal fungi inoculation in plants is the increase of phosphorus absorption ability, by the direct activity of the extramatricial mycelium that allows the exploration of the soil volume. In this way, the mycorrhizal arbuscular fungi make up another chance in the process of getting nutrients for the plants, particularly phosphorus. [ABSTRACT FROM AUTHOR]

Published
2007
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12. Tissue-specific and developmental pattern of expression of the rice sps1 gene.

Author

Chávez-Bárcenas, A T, Valdez-Alarcón, J J, Martínez-Trujillo, M, Chen, L, Xoconostle-Cázares, B, Lucas, W J, and Herrera-Estrella, L

Abstract

Sucrose-phosphate synthase (SPS) is one of the key regulatory enzymes in carbon assimilation and partitioning in plants. SPS plays a central role in the production of sucrose in photosynthetic cells and in the conversion of starch or fatty acids into sucrose in germinating seeds. To explore the mechanisms that regulate the tissue-specific and developmental distribution of SPS, the expression pattern of rice (Oryza sativa) sps1 (GenBank accession no. U33175) was examined by in situ reverse transcriptase-polymerase chain reaction and the expression directed by the sps1 promoter using the beta-glucuronidase reporter gene. It was found that the expression of the rice sps1 gene is limited to mesophyll cells in leaves, the scutellum of germinating seedlings, and pollen of immature inflorescences. During leaf development, the sps1 promoter directs a basipetal pattern of expression that coincides with the distribution of SPS activity during the leaf sink-to-source transition. It was also found that during the vegetative part of the growth cycle, SPS expression and enzymatic activity are highest in the youngest fully expanded leaf. Additionally, it was observed that the expression of the sps1 promoter is regulated by light and dependent on plastid development in photosynthetic tissues, whereas expression in scutellum is independent of both light and plastid development.

Published
2000
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16. Batch and Pulsed Fed-Batch Cultures of Aspergillus flavipes FP-500 Growing on Lemon Peel at Stirred Tank Reactor.

Author

Wolf-Márquez VE, García-García E, García-Rivero M, Aguilar-Osorio G, and Martínez Trujillo MA

Subjects
Aspergillus growth & development, Bioreactors, Citrus chemistry, Fruit chemistry
Abstract

Aspergillus flavipes FP-500 grew up on submerged cultures using lemon peel as the only carbon source, developing several batch and pulsed fed-batch trials on a stirred tank reactor. The effect of carbon source concentration, reducing sugar presence and initial pH on exopectinase and endopectinase production, was analyzed on batch cultures. From this, we observed that the highest substrate concentration favored biomass (X max) but had not influence on the corresponding specific production (q p) of both pectinases; the most acid condition provoked higher endopectinase-specific productions but had not a significant effect on those corresponding to exopectinases; and reducing sugar concentrations higher than 1.5 g/L retarded pectinase production. On the other hand, by employing the pulsed fed-batch operation mode, we observed a prolonged growth phase, and an increase of about twofold on endopectinase production without a significant raise on biomass concentration. So, pulsed fed-batch seems to be a good alternative for obtaining higher endopectinase titers by using high lemon peel quantities without having mixing and repression problems to the system. The usefulness of unstructured kinetic models for explaining, under a theoretic level, the behavior of the fungus along the batch culture with regard to pectinase production was evident.

Published
2015
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