Volatiles esters impart distinct characteristics to the fruit quality. 'Charentais' cantaloupe me... more Volatiles esters impart distinct characteristics to the fruit quality. 'Charentais' cantaloupe melon (Cucumis melo 'cantalupensis') is characterized by abundant sweetness and aromatic flavour. Plant alcohol acyl transferase (AAT) genes have been identified and shown to be involved in aromas production. Recently, two cDNAs (Cm-AAT 1 and Cm-AAT 2) putatively involved in the formation of aroma volatile esters have been isolated from melon fruit. Cm-AAT 1 protein exhibit alcohol acyl transferase activity while no such activity could be detected for Cm-AAT 2. Two new cDNAs (Cm-AAT 3 and Cm-AAT 4) have been isolated from melon fruit that showed 69% and 36% similarity, respectively, with Cm-AAT 1. The percentage similarity over the whole amino acid sequence between them is 34%. Cm-AAT 3 and Cm-AAT 4 show the highest similarity to the tobacco Nt-HSR201 protein and a rose alcohol acyltransferase Rh-AAT 1 , respectively. All Cm-AATs genes, share three conserved regions common to the BAHD acyltransferase gene superfamily. Heterologous expression in yeast revealed that some of the encoded proteins have a wide range of specificity while others are specific to a narrow range of substrates.
Low temperature stresses, also referred to as cold temperature stresses, including chilling and f... more Low temperature stresses, also referred to as cold temperature stresses, including chilling and freezing temperatures, are among the major abiotic stresses that severely reduces plant yield, quality, and marketability and pose a serious threat to plant production during whole plant life cycles. Plant-environment-symbiont interactions determine the symbiotic and crop performance and tolerance to biotic and abiotic stresses. To achieve the optimum outcome, it is essential to consider not only plantsymbiont relationships, but also symbiont adaptation and symbiont-symbiont interactions. Improving multi-symbiotic component systems and symbiont breeding together can be a useful strategy to improve symbiosis and, thus, crop production. In this review article, role of interactions between multi-symbiotic components and plantenvironment-symbiont relationships and the related biotechnology approaches are discussed in order to find the most effective sustainable and environmentally friendly agricultural practices to improve crop performance and mitigate the adverse effects of low temperatures on plants.
International Journal of Food Science & Technology
SummaryAmaranth grains are a source of proteins such as albumins and globulins with well‐balanced... more SummaryAmaranth grains are a source of proteins such as albumins and globulins with well‐balanced amino acids profile since they are rich in lysine and methionine, which are scarce in other cereals. Amaranth proteins also show a great bioavailability that contributes to their high quality and, consequently, become a potential substitute for animal‐based foods. This review aims to provide a comprehensive summary of the recent research on screening of amaranth proteins as well as their isolation, fractionation, amino acid composition and digestibility. In addition, we carried out an important overview of the nutritional benefits of amaranth proteins and its application as ingredients in food systems. The amaranth has an excellent balance of amino acids and bioactive peptides, with potential health benefits. The consumption of amaranth proteins can promote human health due to their potential to reduce the risk of suffering chronic diseases, while their bioactive peptides play a fundame...
The yellowing of florets limits the economic and nutritional value of broccoli during postharvest... more The yellowing of florets limits the economic and nutritional value of broccoli during postharvest. We investigated mechanisms of action of 150 nM phytosulfokine α (PSKα) for delaying florets yellowing in broccoli during cold storage. Our results showed that SUMO E3 ligase (SIZ1) gene expression was higher in florets treated with PSKα, which may prevent endogenous H2O2 accumulation, resulting from the higher activity of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase. Besides, higher expression of methionine sulfoxide reductase and cysteine peroxiredoxin genes, concomitant with higher expression of heat shock proteins 70/90 genes, may arise from higherexpression of SIZ1 gene. Lower expression and activity of phospholipase D and lipoxygenase may be liable for membrane integrity protection featured by lower malondialdehyde accumulation in florets treated with PSKα. Additionally,florets treated with PSKα exhibited higher endogenous cytokinin accumulation which may arise from higher expression of isopentenyl transferase gene, concomitant with lower expression of cytokinin oxidase gene.
Resumen En el presente trabajo se estudió la eficacia del 1-MCP en la disminución de la aparición... more Resumen En el presente trabajo se estudió la eficacia del 1-MCP en la disminución de la aparición de los daños por frío en melón Piel de Sapo cvar. Sancho y sobre algunos parámetros relacionados con el metabolismo oxidativo del fruto. El tratamiento con 1-MCP (750ppb) no mostró cambios significativos en el color, contenido de sólidos solubles y acidez total, mientras que la pérdida de firmeza fue menor en los frutos tratados. Los cambios observados fueron relacionados por una importante reducción de la producción de etileno, así como con un aumento significativo de las actividades enzimáticas antioxidantes, peroxidasa, catalasa y superóxido dismutasa. Introducción Frutos de melón (Cucumis melo) tipo Piel de Sapo muestran gran incidencia de daños por frío cuando se conservan a temperaturas inferiores a 8 ºC, manifestándose como depresiones en la corteza, proceso que se ve acompañado con un proceso de estrés oxidativo y relacionado con la disminución de las actividades antioxidantes t...
In recent years, different epidemiological studies have found significant evidence suggesting an ... more In recent years, different epidemiological studies have found significant evidence suggesting an association between the consumption of diets rich in fruits and vegetables and a low risk of suffering some of the most frequent chronic diseases of Western countries (cancer, cardiovascular diseases, etc.). There are many ways by which foods of plant origin can exert a healthy effect on organisms, but the antioxidant activity has been the main point of attention during the last few years. For this reason, there is presently great interest in the characterization of the antioxidant properties of foods as well as in the determination of which substances have greater activity. However, the antioxidant potential of fruits and vegetable products can change during ripening and/or the post-harvest period. Therefore, during the ripening process, there are quantitative and qualitative changes in the fruit composition which will determine the nutritional quality at each point. Moreover, different...
Tomato is a very important fruit due to the high consumption of it in the world. From the nutriti... more Tomato is a very important fruit due to the high consumption of it in the world. From the nutritional point of view, it also presents interesting characteristics such as the high content of substances with antioxidant activity. It has been assumed that regular intake of dietary antioxidants from fruits and vegetables would lead to a decrease in oxidative damage to
Journal of the Science of Food and Agriculture, 2010
... You have free access to this content Erratum: 1-Methylcyclopropene affects the antioxidant sy... more ... You have free access to this content Erratum: 1-Methylcyclopropene affects the antioxidant system of apricots (Prunus armeniaca L. cv. Búlida) during storage at low temperature. Isabel Egea,; Francisco B Flores,; Maria C Martínez-Madrid,; Felix Romojaro,; Paloma Sánchez-Bel. ...
One strategy to increase the level of drought and salinity tolerance is the transfer of genes cod... more One strategy to increase the level of drought and salinity tolerance is the transfer of genes codifying different types of proteins functionally related to macromolecule protection, such as group 2 of late embryogenesis abundant (LEA) proteins or dehydrins. The TAS14 dehydrin was isolated and characterized in tomato and its expression was induced by osmotic stress (NaCl and mannitol) and abscisic acid (ABA) [Godoy et al., Plant Mol Biol 1994;26:1921-1934], yet its function in drought and salinity tolerance of tomato remains elusive. In this study, transgenic tomato plants overexpressing tas14 gene under the control of the 35SCaMV promoter were generated in order to assess the function of tas14 gene in drought and salinity tolerance. The plants overexpressing tas14 gene achieved improved long-term drought and salinity tolerance without affecting plant growth under non-stress conditions. A mechanism of osmotic stress tolerance via osmotic potential reduction and solutes accumulation, such as sugars and K + is operating in tas14 overexpressing plants in drought conditions. A similar mechanism of osmotic stress tolerance was observed under salinity. Moreover, the overexpression of tas14 gene increased Na + accumulation only in adult leaves whereas in young leaves the accumulated solutes were K + and sugars, which suggests that plants overexpressing tas14 gene are able to distribute the Na + accumulation between young and adult leaves over a prolonged period in stressful conditions. Measurement of ABA shows that the action mechanism of tas14 gene is associated to an earlier and higher accumulation of ABA in leaves in short-term periods. A good feature for the application of this gene in improving drought and salt stress tolerance is the fact that its constitutive expression does not affect plant growth under non-stress conditions and tolerance induced by overexpression of tas14 gene was observed at the different stress degrees applied to long-term.
A screening under salt stress conditions of a T-DNA mutant collection of tomato (Solanum lycopers... more A screening under salt stress conditions of a T-DNA mutant collection of tomato (Solanum lycopersicum L.) led to the identification of the altered response to salt stress 1 (ars1) mutant, which showed a salt-sensitive phenotype. Genetic analysis of the ars1 mutation revealed that a single T-DNA insertion in the ARS1 gene was responsible of the mutant phenotype. ARS1 coded for an R1-MYB type transcription factor and its expression was induced by salinity in leaves. The mutant reduced fruit yield under salt acclimation while in the absence of stress the disruption of ARS1 did not affect this agronomic trait. The stomatal behaviour of ars1 mutant leaves induced higher Na(+) accumulation via the transpiration stream, as the decreases of stomatal conductance and transpiration rate induced by salt stress were markedly lower in the mutant plants. Moreover, the mutation affected stomatal closure in a response mediated by abscisic acid (ABA). The characterization of tomato transgenic lines s...
Tomato is a very important fruit due to the high consumption of it in the world. From the nutriti... more Tomato is a very important fruit due to the high consumption of it in the world. From the nutritional point of view, it also presents interesting characteristics such as the high content of substances with antioxidant activity. It has been assumed that regular intake of dietary antioxidants from fruits and vegetables would lead to a decrease in oxidative damage to key structures in the body, like lipids, proteins and DNA.
The behaviour of transgenic antisense 1-aminocyclopropane-1-carboxylic acid oxidase melon (TAM) w... more The behaviour of transgenic antisense 1-aminocyclopropane-1-carboxylic acid oxidase melon (TAM) was studied during fruit ripening. Work focussed mainly on analysis of the evolution of other plant growth regulators like ABA and polyamines in this type of melon. Physical-chemical and physiological differences from untransformed melon (UTM) (Cucumis melo L. var. cantalupensis Naud. cv. Védrantais) began to appear from the time of the latter's ethylene crisis. Ethylene synthesis was inhibited by 97.7% in TAM at the time when UTM showed maximum ethylene levels. The ripeness index of TAM was lower, despite their higher soluble solids content, due to the higher titratable acidity. Unlike UTM, TAM rind maintained its colour and cell membrane integrity, although there was no difference in the pulp in this respect. Blocking ethylene biosynthesis affected the levels of ABA and the polyamine putrescine, the latter only in the rind. The possible relationship between ethylene, ABA and polyamines, the effect of blocking ethylene biosynthesis on the evolution of these regulators, and their role in fruit ripening are discussed.
A comparative proteomic analysis between tomato fruits stored at chilling and nonchilling tempera... more A comparative proteomic analysis between tomato fruits stored at chilling and nonchilling temperatures was carried out just before the appearance of visual chilling injury symptoms. In this stage of the stress period it was possible to discriminate between proteins involved in symptoms and proteins implicated in response. To investigate the changes of the tomato fruit proteome at this specific stressful condition, twodimensional differential in-gel electrophoresis coupled with spot identification by mass spectrometry has been applied. This proteomic approach allowed the identification of differentially expressed proteins, which are involved in two main biological functions: (i) defensive mechanisms represented by small heat-shock and late embryogenesis proteins, and (ii) reaction to the uncoupling of photosynthetic processes and protein degradation machinery. One of the first changes observed in chilled fruits is the downregulation of ATP synthase, 26S proteasome subunit RPN11 and aspartic proteinase, whereas the first responses in order to deal with the stress are mainly multifunctional proteins involved not only in metabolism but also in stress regulation such as glyceraldehyde phosphate dehydrogenase, 2-oxoglutarate dehydrogenase and invertase. In addition, our data seems to indicate a possible candidate to be used as protein marker for further studies on cold stress; the aldose-1-epimerase, which seems to have an important role in low temperature tolerance.
Tomate (Solanum lycopersicum) y pimiento (Capsicum annuum), son dos especies hortofrutícolas pert... more Tomate (Solanum lycopersicum) y pimiento (Capsicum annuum), son dos especies hortofrutícolas pertenecientes a la familia Solanaceae susceptibles a sufrir daños por frío cuando se almacenan a bajas temperaturas, lo que afecta seriamente a la calidad de los frutos, siendo causa de importantes pérdidas económicas en el sector agro-alimentario. Una de las principales respuestas celulares al estrés por bajas temperaturas consiste en el mantenimiento de la homeostasis osmótica por la acumulación de osmolitos compatibles, para lo que tiene lugar la reprogramación de metabolismos energéticos como la glicólisis, el ciclo de Calvin y el ciclo de Krebs. Se ha abordado este estudio desde una perspectiva proteómica, comparando el proteoma de tomate y de pimiento sometidos a daños por frío para investigar las diferentes respuestas del metabolismo energético a las bajas temperaturas en frutos de estas dos especies. El análisis proteómico se ha realizado mediante electroforesis 2D-DIGE seguida de la identificación de las proteínas diferencialmente expresadas por MALDI-TOF-MS. Previamente a comparar los perfiles proteómicos de ambas especies, dentro de cada una de ellas se ha realizado una comparativa del perfil de frutos conservados a temperatura que inducen daños por frío y de frutos conservados a temperatura que no inducen dichos daños, con el fin de identificar las proteínas diferencialmente expresadas debido a la fisiopatía. Se han observado alteraciones en la fermentación y en el ciclo de Calvin en pimiento y cambios en el metabolismo de carbohidratos compuestos (sacarosa), metabolismo de monosacáridos (glucosa) y cadena de transporte de electrones en tomate. En ambos frutos se han detectado modificaciones en la expresión de enzimas de la glicolisis y del ciclo de Krebs por efecto de la conservación refrigerada, hecho que pone de manifiesto la importancia que estos dos metabolismos parecen tener en la respuesta a los daños por frío.
1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) antisense Cantaloupe melons (Cucumis me... more 1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) antisense Cantaloupe melons (Cucumis melo var. cantalupensis Naud.) unable to produce ethylene were used to identify the characteristic physiological processes occurring during ethylene-dependent ripening and ...
Alcohol dehydrogenases (ADH) participate in the biosynthetic pathway of aroma volatiles in fruit ... more Alcohol dehydrogenases (ADH) participate in the biosynthetic pathway of aroma volatiles in fruit by interconverting aldehydes to alcohols and providing substrates for the formation of esters. Two highly divergent ADH genes (15% identity at the amino acid level) of Cantaloupe Charentais melon (Cucumis melo var. Cantalupensis) have been isolated. Cm-ADH1 belongs to the medium-chain zinc-binding type of ADHs and is highly similar to all ADH genes expressed in fruit isolated so far. Cm-ADH2 belongs to the short-chain type of ADHs. The two encoded proteins are enzymatically active upon expression in yeast. Cm-ADH1 has strong preference for NAPDH as a co-factor, whereas Cm-ADH2 preferentially uses NADH. Both Cm-ADH proteins are much more active as reductases with K m s 10-20 times lower for the conversion of aldehydes to alcohols than for the dehydrogenation of alcohols to aldehydes. They both show strong preference for aliphatic aldehydes but Cm-ADH1 is capable of reducing branched aldehydes such as 3-methylbutyraldehyde, whereas Cm-ADH2 cannot. Both Cm-ADH genes are expressed specifically in fruit and up-regulated during ripening. Gene expression as well as total ADH activity are strongly inhibited in antisense ACC oxidase melons and in melon fruit treated with the ethylene antagonist 1-methyl-cyclopropene (1-MCP), indicating a positive regulation by ethylene. These data suggest that each of the Cm-ADH protein plays a specific role in the regulation of aroma biosynthesis in melon fruit.
Volatiles esters impart distinct characteristics to the fruit quality. 'Charentais' cantaloupe me... more Volatiles esters impart distinct characteristics to the fruit quality. 'Charentais' cantaloupe melon (Cucumis melo 'cantalupensis') is characterized by abundant sweetness and aromatic flavour. Plant alcohol acyl transferase (AAT) genes have been identified and shown to be involved in aromas production. Recently, two cDNAs (Cm-AAT 1 and Cm-AAT 2) putatively involved in the formation of aroma volatile esters have been isolated from melon fruit. Cm-AAT 1 protein exhibit alcohol acyl transferase activity while no such activity could be detected for Cm-AAT 2. Two new cDNAs (Cm-AAT 3 and Cm-AAT 4) have been isolated from melon fruit that showed 69% and 36% similarity, respectively, with Cm-AAT 1. The percentage similarity over the whole amino acid sequence between them is 34%. Cm-AAT 3 and Cm-AAT 4 show the highest similarity to the tobacco Nt-HSR201 protein and a rose alcohol acyltransferase Rh-AAT 1 , respectively. All Cm-AATs genes, share three conserved regions common to the BAHD acyltransferase gene superfamily. Heterologous expression in yeast revealed that some of the encoded proteins have a wide range of specificity while others are specific to a narrow range of substrates.
Low temperature stresses, also referred to as cold temperature stresses, including chilling and f... more Low temperature stresses, also referred to as cold temperature stresses, including chilling and freezing temperatures, are among the major abiotic stresses that severely reduces plant yield, quality, and marketability and pose a serious threat to plant production during whole plant life cycles. Plant-environment-symbiont interactions determine the symbiotic and crop performance and tolerance to biotic and abiotic stresses. To achieve the optimum outcome, it is essential to consider not only plantsymbiont relationships, but also symbiont adaptation and symbiont-symbiont interactions. Improving multi-symbiotic component systems and symbiont breeding together can be a useful strategy to improve symbiosis and, thus, crop production. In this review article, role of interactions between multi-symbiotic components and plantenvironment-symbiont relationships and the related biotechnology approaches are discussed in order to find the most effective sustainable and environmentally friendly agricultural practices to improve crop performance and mitigate the adverse effects of low temperatures on plants.
International Journal of Food Science & Technology
SummaryAmaranth grains are a source of proteins such as albumins and globulins with well‐balanced... more SummaryAmaranth grains are a source of proteins such as albumins and globulins with well‐balanced amino acids profile since they are rich in lysine and methionine, which are scarce in other cereals. Amaranth proteins also show a great bioavailability that contributes to their high quality and, consequently, become a potential substitute for animal‐based foods. This review aims to provide a comprehensive summary of the recent research on screening of amaranth proteins as well as their isolation, fractionation, amino acid composition and digestibility. In addition, we carried out an important overview of the nutritional benefits of amaranth proteins and its application as ingredients in food systems. The amaranth has an excellent balance of amino acids and bioactive peptides, with potential health benefits. The consumption of amaranth proteins can promote human health due to their potential to reduce the risk of suffering chronic diseases, while their bioactive peptides play a fundame...
The yellowing of florets limits the economic and nutritional value of broccoli during postharvest... more The yellowing of florets limits the economic and nutritional value of broccoli during postharvest. We investigated mechanisms of action of 150 nM phytosulfokine α (PSKα) for delaying florets yellowing in broccoli during cold storage. Our results showed that SUMO E3 ligase (SIZ1) gene expression was higher in florets treated with PSKα, which may prevent endogenous H2O2 accumulation, resulting from the higher activity of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase. Besides, higher expression of methionine sulfoxide reductase and cysteine peroxiredoxin genes, concomitant with higher expression of heat shock proteins 70/90 genes, may arise from higherexpression of SIZ1 gene. Lower expression and activity of phospholipase D and lipoxygenase may be liable for membrane integrity protection featured by lower malondialdehyde accumulation in florets treated with PSKα. Additionally,florets treated with PSKα exhibited higher endogenous cytokinin accumulation which may arise from higher expression of isopentenyl transferase gene, concomitant with lower expression of cytokinin oxidase gene.
Resumen En el presente trabajo se estudió la eficacia del 1-MCP en la disminución de la aparición... more Resumen En el presente trabajo se estudió la eficacia del 1-MCP en la disminución de la aparición de los daños por frío en melón Piel de Sapo cvar. Sancho y sobre algunos parámetros relacionados con el metabolismo oxidativo del fruto. El tratamiento con 1-MCP (750ppb) no mostró cambios significativos en el color, contenido de sólidos solubles y acidez total, mientras que la pérdida de firmeza fue menor en los frutos tratados. Los cambios observados fueron relacionados por una importante reducción de la producción de etileno, así como con un aumento significativo de las actividades enzimáticas antioxidantes, peroxidasa, catalasa y superóxido dismutasa. Introducción Frutos de melón (Cucumis melo) tipo Piel de Sapo muestran gran incidencia de daños por frío cuando se conservan a temperaturas inferiores a 8 ºC, manifestándose como depresiones en la corteza, proceso que se ve acompañado con un proceso de estrés oxidativo y relacionado con la disminución de las actividades antioxidantes t...
In recent years, different epidemiological studies have found significant evidence suggesting an ... more In recent years, different epidemiological studies have found significant evidence suggesting an association between the consumption of diets rich in fruits and vegetables and a low risk of suffering some of the most frequent chronic diseases of Western countries (cancer, cardiovascular diseases, etc.). There are many ways by which foods of plant origin can exert a healthy effect on organisms, but the antioxidant activity has been the main point of attention during the last few years. For this reason, there is presently great interest in the characterization of the antioxidant properties of foods as well as in the determination of which substances have greater activity. However, the antioxidant potential of fruits and vegetable products can change during ripening and/or the post-harvest period. Therefore, during the ripening process, there are quantitative and qualitative changes in the fruit composition which will determine the nutritional quality at each point. Moreover, different...
Tomato is a very important fruit due to the high consumption of it in the world. From the nutriti... more Tomato is a very important fruit due to the high consumption of it in the world. From the nutritional point of view, it also presents interesting characteristics such as the high content of substances with antioxidant activity. It has been assumed that regular intake of dietary antioxidants from fruits and vegetables would lead to a decrease in oxidative damage to
Journal of the Science of Food and Agriculture, 2010
... You have free access to this content Erratum: 1-Methylcyclopropene affects the antioxidant sy... more ... You have free access to this content Erratum: 1-Methylcyclopropene affects the antioxidant system of apricots (Prunus armeniaca L. cv. Búlida) during storage at low temperature. Isabel Egea,; Francisco B Flores,; Maria C Martínez-Madrid,; Felix Romojaro,; Paloma Sánchez-Bel. ...
One strategy to increase the level of drought and salinity tolerance is the transfer of genes cod... more One strategy to increase the level of drought and salinity tolerance is the transfer of genes codifying different types of proteins functionally related to macromolecule protection, such as group 2 of late embryogenesis abundant (LEA) proteins or dehydrins. The TAS14 dehydrin was isolated and characterized in tomato and its expression was induced by osmotic stress (NaCl and mannitol) and abscisic acid (ABA) [Godoy et al., Plant Mol Biol 1994;26:1921-1934], yet its function in drought and salinity tolerance of tomato remains elusive. In this study, transgenic tomato plants overexpressing tas14 gene under the control of the 35SCaMV promoter were generated in order to assess the function of tas14 gene in drought and salinity tolerance. The plants overexpressing tas14 gene achieved improved long-term drought and salinity tolerance without affecting plant growth under non-stress conditions. A mechanism of osmotic stress tolerance via osmotic potential reduction and solutes accumulation, such as sugars and K + is operating in tas14 overexpressing plants in drought conditions. A similar mechanism of osmotic stress tolerance was observed under salinity. Moreover, the overexpression of tas14 gene increased Na + accumulation only in adult leaves whereas in young leaves the accumulated solutes were K + and sugars, which suggests that plants overexpressing tas14 gene are able to distribute the Na + accumulation between young and adult leaves over a prolonged period in stressful conditions. Measurement of ABA shows that the action mechanism of tas14 gene is associated to an earlier and higher accumulation of ABA in leaves in short-term periods. A good feature for the application of this gene in improving drought and salt stress tolerance is the fact that its constitutive expression does not affect plant growth under non-stress conditions and tolerance induced by overexpression of tas14 gene was observed at the different stress degrees applied to long-term.
A screening under salt stress conditions of a T-DNA mutant collection of tomato (Solanum lycopers... more A screening under salt stress conditions of a T-DNA mutant collection of tomato (Solanum lycopersicum L.) led to the identification of the altered response to salt stress 1 (ars1) mutant, which showed a salt-sensitive phenotype. Genetic analysis of the ars1 mutation revealed that a single T-DNA insertion in the ARS1 gene was responsible of the mutant phenotype. ARS1 coded for an R1-MYB type transcription factor and its expression was induced by salinity in leaves. The mutant reduced fruit yield under salt acclimation while in the absence of stress the disruption of ARS1 did not affect this agronomic trait. The stomatal behaviour of ars1 mutant leaves induced higher Na(+) accumulation via the transpiration stream, as the decreases of stomatal conductance and transpiration rate induced by salt stress were markedly lower in the mutant plants. Moreover, the mutation affected stomatal closure in a response mediated by abscisic acid (ABA). The characterization of tomato transgenic lines s...
Tomato is a very important fruit due to the high consumption of it in the world. From the nutriti... more Tomato is a very important fruit due to the high consumption of it in the world. From the nutritional point of view, it also presents interesting characteristics such as the high content of substances with antioxidant activity. It has been assumed that regular intake of dietary antioxidants from fruits and vegetables would lead to a decrease in oxidative damage to key structures in the body, like lipids, proteins and DNA.
The behaviour of transgenic antisense 1-aminocyclopropane-1-carboxylic acid oxidase melon (TAM) w... more The behaviour of transgenic antisense 1-aminocyclopropane-1-carboxylic acid oxidase melon (TAM) was studied during fruit ripening. Work focussed mainly on analysis of the evolution of other plant growth regulators like ABA and polyamines in this type of melon. Physical-chemical and physiological differences from untransformed melon (UTM) (Cucumis melo L. var. cantalupensis Naud. cv. Védrantais) began to appear from the time of the latter's ethylene crisis. Ethylene synthesis was inhibited by 97.7% in TAM at the time when UTM showed maximum ethylene levels. The ripeness index of TAM was lower, despite their higher soluble solids content, due to the higher titratable acidity. Unlike UTM, TAM rind maintained its colour and cell membrane integrity, although there was no difference in the pulp in this respect. Blocking ethylene biosynthesis affected the levels of ABA and the polyamine putrescine, the latter only in the rind. The possible relationship between ethylene, ABA and polyamines, the effect of blocking ethylene biosynthesis on the evolution of these regulators, and their role in fruit ripening are discussed.
A comparative proteomic analysis between tomato fruits stored at chilling and nonchilling tempera... more A comparative proteomic analysis between tomato fruits stored at chilling and nonchilling temperatures was carried out just before the appearance of visual chilling injury symptoms. In this stage of the stress period it was possible to discriminate between proteins involved in symptoms and proteins implicated in response. To investigate the changes of the tomato fruit proteome at this specific stressful condition, twodimensional differential in-gel electrophoresis coupled with spot identification by mass spectrometry has been applied. This proteomic approach allowed the identification of differentially expressed proteins, which are involved in two main biological functions: (i) defensive mechanisms represented by small heat-shock and late embryogenesis proteins, and (ii) reaction to the uncoupling of photosynthetic processes and protein degradation machinery. One of the first changes observed in chilled fruits is the downregulation of ATP synthase, 26S proteasome subunit RPN11 and aspartic proteinase, whereas the first responses in order to deal with the stress are mainly multifunctional proteins involved not only in metabolism but also in stress regulation such as glyceraldehyde phosphate dehydrogenase, 2-oxoglutarate dehydrogenase and invertase. In addition, our data seems to indicate a possible candidate to be used as protein marker for further studies on cold stress; the aldose-1-epimerase, which seems to have an important role in low temperature tolerance.
Tomate (Solanum lycopersicum) y pimiento (Capsicum annuum), son dos especies hortofrutícolas pert... more Tomate (Solanum lycopersicum) y pimiento (Capsicum annuum), son dos especies hortofrutícolas pertenecientes a la familia Solanaceae susceptibles a sufrir daños por frío cuando se almacenan a bajas temperaturas, lo que afecta seriamente a la calidad de los frutos, siendo causa de importantes pérdidas económicas en el sector agro-alimentario. Una de las principales respuestas celulares al estrés por bajas temperaturas consiste en el mantenimiento de la homeostasis osmótica por la acumulación de osmolitos compatibles, para lo que tiene lugar la reprogramación de metabolismos energéticos como la glicólisis, el ciclo de Calvin y el ciclo de Krebs. Se ha abordado este estudio desde una perspectiva proteómica, comparando el proteoma de tomate y de pimiento sometidos a daños por frío para investigar las diferentes respuestas del metabolismo energético a las bajas temperaturas en frutos de estas dos especies. El análisis proteómico se ha realizado mediante electroforesis 2D-DIGE seguida de la identificación de las proteínas diferencialmente expresadas por MALDI-TOF-MS. Previamente a comparar los perfiles proteómicos de ambas especies, dentro de cada una de ellas se ha realizado una comparativa del perfil de frutos conservados a temperatura que inducen daños por frío y de frutos conservados a temperatura que no inducen dichos daños, con el fin de identificar las proteínas diferencialmente expresadas debido a la fisiopatía. Se han observado alteraciones en la fermentación y en el ciclo de Calvin en pimiento y cambios en el metabolismo de carbohidratos compuestos (sacarosa), metabolismo de monosacáridos (glucosa) y cadena de transporte de electrones en tomate. En ambos frutos se han detectado modificaciones en la expresión de enzimas de la glicolisis y del ciclo de Krebs por efecto de la conservación refrigerada, hecho que pone de manifiesto la importancia que estos dos metabolismos parecen tener en la respuesta a los daños por frío.
1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) antisense Cantaloupe melons (Cucumis me... more 1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) antisense Cantaloupe melons (Cucumis melo var. cantalupensis Naud.) unable to produce ethylene were used to identify the characteristic physiological processes occurring during ethylene-dependent ripening and ...
Alcohol dehydrogenases (ADH) participate in the biosynthetic pathway of aroma volatiles in fruit ... more Alcohol dehydrogenases (ADH) participate in the biosynthetic pathway of aroma volatiles in fruit by interconverting aldehydes to alcohols and providing substrates for the formation of esters. Two highly divergent ADH genes (15% identity at the amino acid level) of Cantaloupe Charentais melon (Cucumis melo var. Cantalupensis) have been isolated. Cm-ADH1 belongs to the medium-chain zinc-binding type of ADHs and is highly similar to all ADH genes expressed in fruit isolated so far. Cm-ADH2 belongs to the short-chain type of ADHs. The two encoded proteins are enzymatically active upon expression in yeast. Cm-ADH1 has strong preference for NAPDH as a co-factor, whereas Cm-ADH2 preferentially uses NADH. Both Cm-ADH proteins are much more active as reductases with K m s 10-20 times lower for the conversion of aldehydes to alcohols than for the dehydrogenation of alcohols to aldehydes. They both show strong preference for aliphatic aldehydes but Cm-ADH1 is capable of reducing branched aldehydes such as 3-methylbutyraldehyde, whereas Cm-ADH2 cannot. Both Cm-ADH genes are expressed specifically in fruit and up-regulated during ripening. Gene expression as well as total ADH activity are strongly inhibited in antisense ACC oxidase melons and in melon fruit treated with the ethylene antagonist 1-methyl-cyclopropene (1-MCP), indicating a positive regulation by ethylene. These data suggest that each of the Cm-ADH protein plays a specific role in the regulation of aroma biosynthesis in melon fruit.
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