Emma Keck - Academia.edu (original) (raw)

Papers by Emma Keck

The EMBO Journal, Jul 15, 1999

We report the discovery of an Antirrhinum MADS-box gene, FARINELLI (FAR), and the isolation of fa... more We report the discovery of an Antirrhinum MADS-box gene, FARINELLI (FAR), and the isolation of far mutants by a reverse genetic screen. Despite striking similarities between FAR and the class C MADS-box gene PLENA (PLE), the phenotypes of their respective mutants are dramatically different. Unlike ple mutants, which show homeotic conversion of reproductive organs to perianth organs and a loss of floral determinacy, far mutants have normal flowers which are partially male-sterile. Expression studies of PLE and FAR, in wild-type and mutant backgrounds, show complex interactions between the two genes. Double mutant analysis reveals an unexpected, redundant negative control over the B-function MADS-box genes. This feature of the two Antirrhinum C-function-like genes is markedly different from the control of the inner boundary of the B-function expression domain in Arabidopsis, and we propose and discuss a model to account for these differences. The difference in phenotypes of mutants in two highly related genes illustrates the importance of the position within the regulatory network in determining gene function.

Grass and Forage Science, Mar 1, 2006

Festuca rubra subsp. pruinosa is a grass that inhabits the sea cliffs of the Atlantic coasts of E... more Festuca rubra subsp. pruinosa is a grass that inhabits the sea cliffs of the Atlantic coasts of Europe. Four populations of this plant in the northern coast of Galicia, in northern Spain, were analysed for the presence of fungal endophytes. Of the plants included in the study, on average 0AE69 were infected by an intercellular fungal endophyte. Using morphological and molecular characters, this endophyte was identified as Epichloë festucae, a clavicipitaceous, seed-transmitted species. A halfsibling line, consisting of endophyte-free and endophyte-infected plants, was developed and used to test whether the presence of the fungus affected the response of the plants to salinity. Dry weights of infected or uninfected plants, watered with seawater solutions or tap water, did not significantly differ.

Buenas Prácticas en Calidad de la Universidad de Salamanca: recopilación de las I Jornadas Recopilación de las I Jornadas, Dec 15, 2019

E l Servicio Central de Idiomas (en adelante, SCI) comenzó a realizar encuestas para conocer la o... more E l Servicio Central de Idiomas (en adelante, SCI) comenzó a realizar encuestas para conocer la opinión de sus usuarios/as en el curso académico 2001-2002, con un doble objetivo: • Conocer su grado de satisfacción y, analizando esta información, introducir mejoras en los servicios que ofrece a la comunidad universitaria. • Ofrecer un canal de comunicación directo con sus usuarios/as. Las aportaciones realizadas a través de esta vía se estudian y dan lugar a nuevas mejoras.

Buenas Prácticas en Calidad de la Universidad de Salamanca: recopilación de las I Jornadas Recopilación de las I Jornadas, 2019

Journal of Plant Physiology, 2011

Using the TrichoEST database, generated in a previous functional genomics project from the benefi... more Using the TrichoEST database, generated in a previous functional genomics project from the beneficial filamentous fungus Trichoderma harzianum, a gene named Thkel1, which codes for a putative kelch-repeat protein, was isolated and characterized. Silencing of this gene in T. harzianum leads to a reduction of glucosidase activity and mycelial growth under abiotic stress conditions. Expression of this gene in Arabidopsis enhances plant tolerance to salt and osmotic stresses, accompanied by an increase in glucosidase activity and a reduction of abscisic acid levels compared to those observed in wild-type plants. Data presented throughout this article suggest the high value of T. harzianum as a source of genes able to facilitate the achievement of producing plants resistant to abiotic stresses without alteration of their phenotype.

Anti-Cancer Agents in Medicinal Chemistry, 2009

Gastrointestinal tumours constitute one of the worldwide leading causes of death. One important l... more Gastrointestinal tumours constitute one of the worldwide leading causes of death. One important limitation in the battle against these types of cancer is their lack of sensitivity to currently available chemotherapy and the development of drug resistance during treatment. The mechanisms responsible for this refractivity include a reduction in drug uptake, enhanced drug export, intracellular inactivation of the effective agent, alteration of the molecular target, an increase in the activity of the target route to be inhibited or the appearance or stimulation of alternative routes, enhanced repair of drug-induced modification in the target molecules, and activation/inhibition of intracellular signalling pathways, which leads to a negative balance between apoptosis/survival of tumour cells. A better understanding of these mechanisms is needed in order to develop both accurate tests to predict the lack of response to chemotherapy and novel approaches aimed to overcome the drug resistanc...

The EMBO Journal, 1999

We report the discovery of an Antirrhinum MADS-box gene, FARINELLI (FAR), and the isolation of fa... more We report the discovery of an Antirrhinum MADS-box gene, FARINELLI (FAR), and the isolation of far mutants by a reverse genetic screen. Despite striking similarities between FAR and the class C MADS-box gene PLENA (PLE), the phenotypes of their respective mutants are dramatically different. Unlike ple mutants, which show homeotic conversion of reproductive organs to perianth organs and a loss of floral determinacy, far mutants have normal flowers which are partially male-sterile. Expression studies of PLE and FAR, in wild-type and mutant backgrounds, show complex interactions between the two genes. Double mutant analysis reveals an unexpected, redundant negative control over the B-function MADS-box genes. This feature of the two Antirrhinum C-function-like genes is markedly different from the control of the inner boundary of the B-function expression domain in Arabidopsis, and we propose and discuss a model to account for these differences. The difference in phenotypes of mutants in two highly related genes illustrates the importance of the position within the regulatory network in determining gene function.

Microbial Ecology, 2005

Strain identification in situ is an important factor in the monitoring of microorganisms used in ... more Strain identification in situ is an important factor in the monitoring of microorganisms used in the field. In this study, we demonstrated the use of sequence-characterized amplified region (SCAR) markers to detect genomic DNA from Trichoderma harzianum 2413 from soil. Two primers (SCAR A1/SCAR A1c) were tested against DNA of 27 isolates of Trichoderma spp. and amplified a 990-bp fragment

Mycological Research, 2004

Genetic variability within 69 biocontrol isolates of Trichoderma, obtained from different geograp... more Genetic variability within 69 biocontrol isolates of Trichoderma, obtained from different geographical locations and culture collections and selected as biocontrol agents, was studied. Sequence data, obtained from the ITS1 region of rDNA and a fragment of the translation elongation factor 1 (tef1) gene, were used in a phylogenetic analysis.

Current Biology, 2002

ity in maize [5] and formation of ectopic meristems in barley [6]. In tomato, class I KNOX genes ... more ity in maize [5] and formation of ectopic meristems in barley [6]. In tomato, class I KNOX genes are normally King's Buildings Mayfield Road, Edinburgh EH9 3JR expressed in the compound leaves, and overexpression leads to an increased degree of compounding [7]. Many novel characters are associated with the petals of flowers adapted to animal pollination (e.g., [8]). The Norwich Research Park, Norwich NR4 7UH United Kingdom bee-pollinated snapdragon Antirrhinum majus has a dorsiventrally asymmetric (zygomorphic) corolla with petals united proximally forming a tube. The three lower petals are further united distally and folded in to form Summary the palate, which limits access to the tube and presents an attractive outer face. All relatives of Antirrhinum Background: Petal spurs-tubular outgrowths that colwithin the tribe Antirrhineae have tubular corollas, and lect nectar-are considered key innovations because of most show zygomorphy and have a palate [9]. They have their ability to change pollinator specificity and so cause a nectary encircling the base of the carpel and many reproductive isolation and speciation. Spurs have arisen also have a spur-an outgrowth of the ventral petal frequently and rapidly in many taxa. To test their potenin which nectar collects [9]. Petal spurs have arisen tial origins, we isolated spontaneous dominant mutaindependently in many angiosperm families and are contions at two loci, HIRZ and INA, that cause novel outsidered a key innovation because their loss or gain can growths from Antirrhinum petals, resembling the petal alter pollinator specificity [10-11] and might therefore spurs of closely related genera. lead to reproductive isolation and speciation [12]. The origins of spurs, however, remain obscure. Within Antir-Results: HIRZ and INA were isolated and shown to enrhineae, all Antirrhinum species lack prominent spurs, code similar KNOX homeodomain proteins that are norwhereas their closest relatives have them [9]. Current mally expressed only in apical meristems and are likely phylogenies [13] do not reveal whether Antirrhinum is to act redundantly. Both dominant mutations were more likely to have arisen from a nonspurred ancestor caused by transposon insertions in noncoding regions or to have lost spurs. that caused ectopic expression of functional transcripts, We have identified spontaneous dominant mutations, either in petals or in all lateral organs with more pleiotro-Hirzina-d153 (Hirz-d153) and Invaginata-d1 (Ina-d1), that pic effects. Formation of a spur-like outgrowth, which alter corolla development in Antirrhinum majus. We resembled an ectopic petal tube, was dependent both show that they affect closely related KNOX homeobox on KNOX gene expression and dorsiventral asymmetry genes that are normally expressed only in apical meriof the flower. stems. Both mutations result from transposon insertions that cause ectopic expression in floral organs and, in Conclusions: These mutations provide an example of the case of Hirz-d153, in other lateral organs. Ectopic how petal spurs might evolve rapidly due to changes in HIRZ and INA expression results in duplication of the regulatory gene expression. petal tube to form a structure that resembles the spur of other Antirrhineae in its morphology and position.

Journal of Plant Physiology, 2011

Using the TrichoEST database, generated in a previous functional genomics project from the benefi... more Using the TrichoEST database, generated in a previous functional genomics project from the beneficial filamentous fungus Trichoderma harzianum, a gene named Thkel1, which codes for a putative kelch-repeat protein, was isolated and characterized. Silencing of this gene in T. harzianum leads to a reduction of glucosidase activity and mycelial growth under abiotic stress conditions. Expression of this gene in Arabidopsis enhances plant tolerance to salt and osmotic stresses, accompanied by an increase in glucosidase activity and a reduction of abscisic acid levels compared to those observed in wild-type plants. Data presented throughout this article suggest the high value of T. harzianum as a source of genes able to facilitate the achievement of producing plants resistant to abiotic stresses without alteration of their phenotype.

The EMBO Journal, Jul 15, 1999

We report the discovery of an Antirrhinum MADS-box gene, FARINELLI (FAR), and the isolation of fa... more We report the discovery of an Antirrhinum MADS-box gene, FARINELLI (FAR), and the isolation of far mutants by a reverse genetic screen. Despite striking similarities between FAR and the class C MADS-box gene PLENA (PLE), the phenotypes of their respective mutants are dramatically different. Unlike ple mutants, which show homeotic conversion of reproductive organs to perianth organs and a loss of floral determinacy, far mutants have normal flowers which are partially male-sterile. Expression studies of PLE and FAR, in wild-type and mutant backgrounds, show complex interactions between the two genes. Double mutant analysis reveals an unexpected, redundant negative control over the B-function MADS-box genes. This feature of the two Antirrhinum C-function-like genes is markedly different from the control of the inner boundary of the B-function expression domain in Arabidopsis, and we propose and discuss a model to account for these differences. The difference in phenotypes of mutants in two highly related genes illustrates the importance of the position within the regulatory network in determining gene function.

Grass and Forage Science, Mar 1, 2006

Festuca rubra subsp. pruinosa is a grass that inhabits the sea cliffs of the Atlantic coasts of E... more Festuca rubra subsp. pruinosa is a grass that inhabits the sea cliffs of the Atlantic coasts of Europe. Four populations of this plant in the northern coast of Galicia, in northern Spain, were analysed for the presence of fungal endophytes. Of the plants included in the study, on average 0AE69 were infected by an intercellular fungal endophyte. Using morphological and molecular characters, this endophyte was identified as Epichloë festucae, a clavicipitaceous, seed-transmitted species. A halfsibling line, consisting of endophyte-free and endophyte-infected plants, was developed and used to test whether the presence of the fungus affected the response of the plants to salinity. Dry weights of infected or uninfected plants, watered with seawater solutions or tap water, did not significantly differ.

Buenas Prácticas en Calidad de la Universidad de Salamanca: recopilación de las I Jornadas Recopilación de las I Jornadas, Dec 15, 2019

E l Servicio Central de Idiomas (en adelante, SCI) comenzó a realizar encuestas para conocer la o... more E l Servicio Central de Idiomas (en adelante, SCI) comenzó a realizar encuestas para conocer la opinión de sus usuarios/as en el curso académico 2001-2002, con un doble objetivo: • Conocer su grado de satisfacción y, analizando esta información, introducir mejoras en los servicios que ofrece a la comunidad universitaria. • Ofrecer un canal de comunicación directo con sus usuarios/as. Las aportaciones realizadas a través de esta vía se estudian y dan lugar a nuevas mejoras.

Buenas Prácticas en Calidad de la Universidad de Salamanca: recopilación de las I Jornadas Recopilación de las I Jornadas, 2019

Journal of Plant Physiology, 2011

Using the TrichoEST database, generated in a previous functional genomics project from the benefi... more Using the TrichoEST database, generated in a previous functional genomics project from the beneficial filamentous fungus Trichoderma harzianum, a gene named Thkel1, which codes for a putative kelch-repeat protein, was isolated and characterized. Silencing of this gene in T. harzianum leads to a reduction of glucosidase activity and mycelial growth under abiotic stress conditions. Expression of this gene in Arabidopsis enhances plant tolerance to salt and osmotic stresses, accompanied by an increase in glucosidase activity and a reduction of abscisic acid levels compared to those observed in wild-type plants. Data presented throughout this article suggest the high value of T. harzianum as a source of genes able to facilitate the achievement of producing plants resistant to abiotic stresses without alteration of their phenotype.

Anti-Cancer Agents in Medicinal Chemistry, 2009

Gastrointestinal tumours constitute one of the worldwide leading causes of death. One important l... more Gastrointestinal tumours constitute one of the worldwide leading causes of death. One important limitation in the battle against these types of cancer is their lack of sensitivity to currently available chemotherapy and the development of drug resistance during treatment. The mechanisms responsible for this refractivity include a reduction in drug uptake, enhanced drug export, intracellular inactivation of the effective agent, alteration of the molecular target, an increase in the activity of the target route to be inhibited or the appearance or stimulation of alternative routes, enhanced repair of drug-induced modification in the target molecules, and activation/inhibition of intracellular signalling pathways, which leads to a negative balance between apoptosis/survival of tumour cells. A better understanding of these mechanisms is needed in order to develop both accurate tests to predict the lack of response to chemotherapy and novel approaches aimed to overcome the drug resistanc...

The EMBO Journal, 1999

We report the discovery of an Antirrhinum MADS-box gene, FARINELLI (FAR), and the isolation of fa... more We report the discovery of an Antirrhinum MADS-box gene, FARINELLI (FAR), and the isolation of far mutants by a reverse genetic screen. Despite striking similarities between FAR and the class C MADS-box gene PLENA (PLE), the phenotypes of their respective mutants are dramatically different. Unlike ple mutants, which show homeotic conversion of reproductive organs to perianth organs and a loss of floral determinacy, far mutants have normal flowers which are partially male-sterile. Expression studies of PLE and FAR, in wild-type and mutant backgrounds, show complex interactions between the two genes. Double mutant analysis reveals an unexpected, redundant negative control over the B-function MADS-box genes. This feature of the two Antirrhinum C-function-like genes is markedly different from the control of the inner boundary of the B-function expression domain in Arabidopsis, and we propose and discuss a model to account for these differences. The difference in phenotypes of mutants in two highly related genes illustrates the importance of the position within the regulatory network in determining gene function.

Microbial Ecology, 2005

Strain identification in situ is an important factor in the monitoring of microorganisms used in ... more Strain identification in situ is an important factor in the monitoring of microorganisms used in the field. In this study, we demonstrated the use of sequence-characterized amplified region (SCAR) markers to detect genomic DNA from Trichoderma harzianum 2413 from soil. Two primers (SCAR A1/SCAR A1c) were tested against DNA of 27 isolates of Trichoderma spp. and amplified a 990-bp fragment

Mycological Research, 2004

Genetic variability within 69 biocontrol isolates of Trichoderma, obtained from different geograp... more Genetic variability within 69 biocontrol isolates of Trichoderma, obtained from different geographical locations and culture collections and selected as biocontrol agents, was studied. Sequence data, obtained from the ITS1 region of rDNA and a fragment of the translation elongation factor 1 (tef1) gene, were used in a phylogenetic analysis.

Current Biology, 2002

ity in maize [5] and formation of ectopic meristems in barley [6]. In tomato, class I KNOX genes ... more ity in maize [5] and formation of ectopic meristems in barley [6]. In tomato, class I KNOX genes are normally King's Buildings Mayfield Road, Edinburgh EH9 3JR expressed in the compound leaves, and overexpression leads to an increased degree of compounding [7]. Many novel characters are associated with the petals of flowers adapted to animal pollination (e.g., [8]). The Norwich Research Park, Norwich NR4 7UH United Kingdom bee-pollinated snapdragon Antirrhinum majus has a dorsiventrally asymmetric (zygomorphic) corolla with petals united proximally forming a tube. The three lower petals are further united distally and folded in to form Summary the palate, which limits access to the tube and presents an attractive outer face. All relatives of Antirrhinum Background: Petal spurs-tubular outgrowths that colwithin the tribe Antirrhineae have tubular corollas, and lect nectar-are considered key innovations because of most show zygomorphy and have a palate [9]. They have their ability to change pollinator specificity and so cause a nectary encircling the base of the carpel and many reproductive isolation and speciation. Spurs have arisen also have a spur-an outgrowth of the ventral petal frequently and rapidly in many taxa. To test their potenin which nectar collects [9]. Petal spurs have arisen tial origins, we isolated spontaneous dominant mutaindependently in many angiosperm families and are contions at two loci, HIRZ and INA, that cause novel outsidered a key innovation because their loss or gain can growths from Antirrhinum petals, resembling the petal alter pollinator specificity [10-11] and might therefore spurs of closely related genera. lead to reproductive isolation and speciation [12]. The origins of spurs, however, remain obscure. Within Antir-Results: HIRZ and INA were isolated and shown to enrhineae, all Antirrhinum species lack prominent spurs, code similar KNOX homeodomain proteins that are norwhereas their closest relatives have them [9]. Current mally expressed only in apical meristems and are likely phylogenies [13] do not reveal whether Antirrhinum is to act redundantly. Both dominant mutations were more likely to have arisen from a nonspurred ancestor caused by transposon insertions in noncoding regions or to have lost spurs. that caused ectopic expression of functional transcripts, We have identified spontaneous dominant mutations, either in petals or in all lateral organs with more pleiotro-Hirzina-d153 (Hirz-d153) and Invaginata-d1 (Ina-d1), that pic effects. Formation of a spur-like outgrowth, which alter corolla development in Antirrhinum majus. We resembled an ectopic petal tube, was dependent both show that they affect closely related KNOX homeobox on KNOX gene expression and dorsiventral asymmetry genes that are normally expressed only in apical meriof the flower. stems. Both mutations result from transposon insertions that cause ectopic expression in floral organs and, in Conclusions: These mutations provide an example of the case of Hirz-d153, in other lateral organs. Ectopic how petal spurs might evolve rapidly due to changes in HIRZ and INA expression results in duplication of the regulatory gene expression. petal tube to form a structure that resembles the spur of other Antirrhineae in its morphology and position.

Journal of Plant Physiology, 2011

Using the TrichoEST database, generated in a previous functional genomics project from the benefi... more Using the TrichoEST database, generated in a previous functional genomics project from the beneficial filamentous fungus Trichoderma harzianum, a gene named Thkel1, which codes for a putative kelch-repeat protein, was isolated and characterized. Silencing of this gene in T. harzianum leads to a reduction of glucosidase activity and mycelial growth under abiotic stress conditions. Expression of this gene in Arabidopsis enhances plant tolerance to salt and osmotic stresses, accompanied by an increase in glucosidase activity and a reduction of abscisic acid levels compared to those observed in wild-type plants. Data presented throughout this article suggest the high value of T. harzianum as a source of genes able to facilitate the achievement of producing plants resistant to abiotic stresses without alteration of their phenotype.