The development of high nitrogen use efficiency (NUE) cultivars under low N inputs is required fo... more The development of high nitrogen use efficiency (NUE) cultivars under low N inputs is required for sustainable agriculture. To this end, in this study, we analyzed the impact of long-term suboptimal N conditions on the metabolome and transcriptome of tomato to identify specific molecular processes and regulators at the organ scale. Physiological and metabolic analysis revealed specific responses to maintain glutamate, asparagine, and sucrose synthesis in leaves for partition to sustain growth, while assimilated C surplus is stored in the roots. The transcriptomic analyses allowed us to identify root and leaf sets of genes whose expression depends on N availability. GO analyses of the identified genes revealed conserved biological functions involved in C and N metabolism and remobilization as well as other specifics such as the mitochondrial alternative respiration and chloroplastic cyclic electron flux. In addition, integrative analyses uncovered N regulated genes in root and leaf c...
Nitrate is an essential macronutrient and a signal molecule that regulates the expression of mult... more Nitrate is an essential macronutrient and a signal molecule that regulates the expression of multiple genes involved in plant growth and development. Here, we describe the participation of Arabidopsis DNA binding with one finger (DOF) transcription factor CDF3 in nitrate responses and shows that CDF3 gene is induced under nitrate starvation. Moreover, knockout cdf3 mutant plants exhibit nitrate-dependent lateral and primary root modifications, whereas CDF3 overexpression plants show increased biomass and enhanced root development under both nitrogen poor and rich conditions. Expression analyses of 35S::CDF3 lines reveled that CDF3 regulates the expression of an important set of nitrate responsive genes including, glutamine synthetase-1, glutamate synthase-2, nitrate reductase-1, and nitrate transporters NRT2.1, NRT2.4, and NRT2.5 as well as carbon assimilation genes like PK1 and PEPC1 in response to N availability. Consistently, metabolite profiling disclosed that the total amount o...
Cycling Dof Factor (CDF) transcription factors (TFs) are involved in multiple processes related t... more Cycling Dof Factor (CDF) transcription factors (TFs) are involved in multiple processes related to plant growth and development. A member of this family, CDF3, has recently been linked in Arabidopsis to the regulation of primary metabolism and abiotic stress responses, but its role in crop production under stress is still unknown. In this study, we characterized tomato plants overexpressing the CDF3 genes from Arabidopsis and tomato and analyzed their effects on growth and yield under salinity, additionally gaining deeper insights into the molecular function of these TFs. Our results provide evidence for higher biomass production and yield in the 35S::AtCDF3 and 35S::SlCDF3 plants, likely due to a higher photosynthetic capacity resulting in increased sucrose availability. Transcriptome analysis revealed that CDF3 genes regulate a set of genes involved in redox homeostasis, photosynthesis performance and primary metabolism that lead to enhanced biomass production. Consistently, metab...
DNA-binding with one finger (DOF)-type transcription factors are involved in many fundamental pro... more DNA-binding with one finger (DOF)-type transcription factors are involved in many fundamental processes in higher plants, from responses to light and phytohormones to flowering time and seed maturation, but their relation with abiotic stress tolerance is largely unknown. Here, we identify the roles of CDF3, an Arabidopsis DOF gene in abiotic stress responses and developmental processes like flowering time. CDF3 is highly induced by drought, extreme temperatures and abscisic acid treatment. The CDF3 T-DNA insertion mutant cdf3-1 is much more sensitive to drought and low temperature stress, whereas CDF3 overexpression enhances the tolerance of transgenic plants to drought, cold and osmotic stress and promotes late flowering. Transcriptome analysis revealed that CDF3 regulates a set of genes involved in cellular osmoprotection and oxidative stress, including the stress tolerance transcription factors CBFs, DREB2A and ZAT12, which involve both gigantea-dependent and independent pathways. Consistently, metabolite profiling disclosed that the total amount of some protective metabolites including γ-aminobutyric acid, proline, glutamine and sucrose were higher in CDF3-overexpressing plants. Taken together, these results indicate that CDF3 plays a multifaceted role acting on both flowering time and abiotic stress tolerance, in part by controlling the CBF/DREB2A-CRT/DRE and ZAT10/12 modules.
This review deals with phytocystatins, focussing on their potential role as defence proteins agai... more This review deals with phytocystatins, focussing on their potential role as defence proteins against phytophagous arthropods. Information about the evolutionary, molecular and biochemical features and inhibitory properties of phytocystatins are presented. Cystatin ability to inhibit heterologous cysteine protease activities is commented on as well as some approaches of tailoring cystatin specificity to enhance their defence function towards pests. A general landscape on the digestive proteases of phytophagous insects and acari and the remarkable plasticity of their digestive physiology after feeding on cystatins are highlighted. Biotechnological approaches to produce recombinant cystatins to be added to artificial diets or to be sprayed as insecticide-acaricide compounds and the of use cystatins as transgenes are discussed. Multiple examples and applications are included to end with some conclusions and future perspectives.
The effects of different prey regimes on the performance and digestive physiology of the spined s... more The effects of different prey regimes on the performance and digestive physiology of the spined soldier bug, Podisus maculiventris (Say) (Hemiptera: Pentatomidae), were assessed. Specifically, P. maculiventris nymphs were fed on Colorado potato beetle (CPB), Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), larvae; Egyptian cotton leafworm (ECW); Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae); larvae; Calliphora spp. (CAL) (Diptera: Calliphoridae) pupae or a mixture of the three prey. No differences in development and weight gain were observed when P. maculiventris nymphs were fed different prey species (CPB, ECW or CAL). However, an increase in weight gain and a reduction in the duration of the stadia were observed for nymphs fed with a mixture of the three prey. To investigate the physiological background, biochemical analysis were carried out on insects dissected at the end of the feeding assay. We have found that the proteolytic activity in the salivary glands of P. maculiventris nymphs was not affected by prey species, whereas the relative activity of these proteases in the midgut depends on the prey. Moreover, gel assays proved that the proteolytic profiles of midguts from P. maculiventris nymphs feeding on CPB, ECW and CPB closely resembled those of their prey. All together, these results suggest that P. maculiventris may utilize enzymes from the prey they consume that may facilitate the process of digestion.
Tomato is one of the most important horticultural crops worldwide, and is cultivated in semi-arid... more Tomato is one of the most important horticultural crops worldwide, and is cultivated in semi-arid regions in which soil and groundwater salinity is an increasing limitation to yield. The assessment of the responses of new cultivars to salt and the comparisons among cultivars and wild species are of great interest in tomato breeding. This assay provides a reproducible and reliable method for screening tomato responses to NaCl salinity under hydroponic conditions in growth chambers. Although NaCl is the most commonly used salt in salinity studies, other salts such as Na2SO4, MgCl2 or MgSO4, usually found in saline soils, can also be assayed (Nebauer et al., 2013). Plants can be maintained for 30-45 days under the described conditions, although significant effects on growth can be observed after 10 days,
Salinity is an important environmental constraint to crop productivity in arid and semi-arid regi... more Salinity is an important environmental constraint to crop productivity in arid and semi-arid regions of the world. The evaluation of the responses to salinity of different Arabidopsis ecotypes or transgenic lines is important to identify and investigate the role of different key genes. These new characterized genes involved in the response to salinity stress are of great interest to be incorporated in crops breeding programs. Here we provide a reproducible method to evaluate the performance of Arabidopsis lines to salinity stress by analysing primary and lateral root growth and fresh weight of plants grown under in vitro conditions in growth chambers. Even though NaCl is the most frequent used salinity tests, other salts (e.g. KCl, MgCl2) can be also evaluated by this method. Arabidopsis plants can be maintained for 15-20 days in these conditions, although effects on growth and biomass can be observed, depending on the used salt and concentration, within the first 10 days.
During the last years, improvement of bio-refinery technologies to process plant biomass into bio... more During the last years, improvement of bio-refinery technologies to process plant biomass into biofuel has led to an increased study and development of candidate biomass crops. The feasibility of using cellulosic fuels will be determined by the capacity to produce large amounts of reasonably priced feedstock without jeopardizing food security or the environment. Therefore, the combined supply of lignocelluloses from organic residues and bioenergy dedicated cropping systems are necessary to support renewable supply of cellulosic biofuel and other bio-commodities. A high-yield potential is a principal requirement for a biomass cropping system. Additionally, those yields must be preferably achieved with minimal costs and agricultural inputs, such as fertilizer and irrigation. Moreover, the effects on soil productivity are an important issue, since nutrients are surely removed from the field at every harvest. Our research line is focused on the study of regulatory networks involved in pl...
Plant physiology and biochemistry : PPB / Société française de physiologie végétale, 2011
Protease inhibitors from plants have been involved in defence mechanisms against pests and pathog... more Protease inhibitors from plants have been involved in defence mechanisms against pests and pathogens. Phytocystatins and trypsin/α-amylase inhibitors are two of the best characterized protease inhibitor families in plants. In barley, thirteen cystatins (HvCPI-1 to 13) and the BTI-CMe trypsin inhibitor have been previously studied. Their capacity to inhibit pest digestive proteases, and the negative in vivo effect caused by plants expressing these inhibitors on pests support the defence function of these proteins. Barley cystatins are also able to inhibit in vitro fungal growth. However, the antifungal effect of these inhibitors in vivo had not been previously tested. Moreover, their in vitro and in vivo effect on plant pathogenous bacteria is still unknown. In order to obtain new insights on this feature, in vitro assays were made against different bacterial and fungal pathogens of plants using the trypsin inhibitor BTI-CMe and the thirteen barley cystatins. Most barley cystatins an...
The development of high nitrogen use efficiency (NUE) cultivars under low N inputs is required fo... more The development of high nitrogen use efficiency (NUE) cultivars under low N inputs is required for sustainable agriculture. To this end, in this study, we analyzed the impact of long-term suboptimal N conditions on the metabolome and transcriptome of tomato to identify specific molecular processes and regulators at the organ scale. Physiological and metabolic analysis revealed specific responses to maintain glutamate, asparagine, and sucrose synthesis in leaves for partition to sustain growth, while assimilated C surplus is stored in the roots. The transcriptomic analyses allowed us to identify root and leaf sets of genes whose expression depends on N availability. GO analyses of the identified genes revealed conserved biological functions involved in C and N metabolism and remobilization as well as other specifics such as the mitochondrial alternative respiration and chloroplastic cyclic electron flux. In addition, integrative analyses uncovered N regulated genes in root and leaf c...
Nitrate is an essential macronutrient and a signal molecule that regulates the expression of mult... more Nitrate is an essential macronutrient and a signal molecule that regulates the expression of multiple genes involved in plant growth and development. Here, we describe the participation of Arabidopsis DNA binding with one finger (DOF) transcription factor CDF3 in nitrate responses and shows that CDF3 gene is induced under nitrate starvation. Moreover, knockout cdf3 mutant plants exhibit nitrate-dependent lateral and primary root modifications, whereas CDF3 overexpression plants show increased biomass and enhanced root development under both nitrogen poor and rich conditions. Expression analyses of 35S::CDF3 lines reveled that CDF3 regulates the expression of an important set of nitrate responsive genes including, glutamine synthetase-1, glutamate synthase-2, nitrate reductase-1, and nitrate transporters NRT2.1, NRT2.4, and NRT2.5 as well as carbon assimilation genes like PK1 and PEPC1 in response to N availability. Consistently, metabolite profiling disclosed that the total amount o...
Cycling Dof Factor (CDF) transcription factors (TFs) are involved in multiple processes related t... more Cycling Dof Factor (CDF) transcription factors (TFs) are involved in multiple processes related to plant growth and development. A member of this family, CDF3, has recently been linked in Arabidopsis to the regulation of primary metabolism and abiotic stress responses, but its role in crop production under stress is still unknown. In this study, we characterized tomato plants overexpressing the CDF3 genes from Arabidopsis and tomato and analyzed their effects on growth and yield under salinity, additionally gaining deeper insights into the molecular function of these TFs. Our results provide evidence for higher biomass production and yield in the 35S::AtCDF3 and 35S::SlCDF3 plants, likely due to a higher photosynthetic capacity resulting in increased sucrose availability. Transcriptome analysis revealed that CDF3 genes regulate a set of genes involved in redox homeostasis, photosynthesis performance and primary metabolism that lead to enhanced biomass production. Consistently, metab...
DNA-binding with one finger (DOF)-type transcription factors are involved in many fundamental pro... more DNA-binding with one finger (DOF)-type transcription factors are involved in many fundamental processes in higher plants, from responses to light and phytohormones to flowering time and seed maturation, but their relation with abiotic stress tolerance is largely unknown. Here, we identify the roles of CDF3, an Arabidopsis DOF gene in abiotic stress responses and developmental processes like flowering time. CDF3 is highly induced by drought, extreme temperatures and abscisic acid treatment. The CDF3 T-DNA insertion mutant cdf3-1 is much more sensitive to drought and low temperature stress, whereas CDF3 overexpression enhances the tolerance of transgenic plants to drought, cold and osmotic stress and promotes late flowering. Transcriptome analysis revealed that CDF3 regulates a set of genes involved in cellular osmoprotection and oxidative stress, including the stress tolerance transcription factors CBFs, DREB2A and ZAT12, which involve both gigantea-dependent and independent pathways. Consistently, metabolite profiling disclosed that the total amount of some protective metabolites including γ-aminobutyric acid, proline, glutamine and sucrose were higher in CDF3-overexpressing plants. Taken together, these results indicate that CDF3 plays a multifaceted role acting on both flowering time and abiotic stress tolerance, in part by controlling the CBF/DREB2A-CRT/DRE and ZAT10/12 modules.
This review deals with phytocystatins, focussing on their potential role as defence proteins agai... more This review deals with phytocystatins, focussing on their potential role as defence proteins against phytophagous arthropods. Information about the evolutionary, molecular and biochemical features and inhibitory properties of phytocystatins are presented. Cystatin ability to inhibit heterologous cysteine protease activities is commented on as well as some approaches of tailoring cystatin specificity to enhance their defence function towards pests. A general landscape on the digestive proteases of phytophagous insects and acari and the remarkable plasticity of their digestive physiology after feeding on cystatins are highlighted. Biotechnological approaches to produce recombinant cystatins to be added to artificial diets or to be sprayed as insecticide-acaricide compounds and the of use cystatins as transgenes are discussed. Multiple examples and applications are included to end with some conclusions and future perspectives.
The effects of different prey regimes on the performance and digestive physiology of the spined s... more The effects of different prey regimes on the performance and digestive physiology of the spined soldier bug, Podisus maculiventris (Say) (Hemiptera: Pentatomidae), were assessed. Specifically, P. maculiventris nymphs were fed on Colorado potato beetle (CPB), Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), larvae; Egyptian cotton leafworm (ECW); Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae); larvae; Calliphora spp. (CAL) (Diptera: Calliphoridae) pupae or a mixture of the three prey. No differences in development and weight gain were observed when P. maculiventris nymphs were fed different prey species (CPB, ECW or CAL). However, an increase in weight gain and a reduction in the duration of the stadia were observed for nymphs fed with a mixture of the three prey. To investigate the physiological background, biochemical analysis were carried out on insects dissected at the end of the feeding assay. We have found that the proteolytic activity in the salivary glands of P. maculiventris nymphs was not affected by prey species, whereas the relative activity of these proteases in the midgut depends on the prey. Moreover, gel assays proved that the proteolytic profiles of midguts from P. maculiventris nymphs feeding on CPB, ECW and CPB closely resembled those of their prey. All together, these results suggest that P. maculiventris may utilize enzymes from the prey they consume that may facilitate the process of digestion.
Tomato is one of the most important horticultural crops worldwide, and is cultivated in semi-arid... more Tomato is one of the most important horticultural crops worldwide, and is cultivated in semi-arid regions in which soil and groundwater salinity is an increasing limitation to yield. The assessment of the responses of new cultivars to salt and the comparisons among cultivars and wild species are of great interest in tomato breeding. This assay provides a reproducible and reliable method for screening tomato responses to NaCl salinity under hydroponic conditions in growth chambers. Although NaCl is the most commonly used salt in salinity studies, other salts such as Na2SO4, MgCl2 or MgSO4, usually found in saline soils, can also be assayed (Nebauer et al., 2013). Plants can be maintained for 30-45 days under the described conditions, although significant effects on growth can be observed after 10 days,
Salinity is an important environmental constraint to crop productivity in arid and semi-arid regi... more Salinity is an important environmental constraint to crop productivity in arid and semi-arid regions of the world. The evaluation of the responses to salinity of different Arabidopsis ecotypes or transgenic lines is important to identify and investigate the role of different key genes. These new characterized genes involved in the response to salinity stress are of great interest to be incorporated in crops breeding programs. Here we provide a reproducible method to evaluate the performance of Arabidopsis lines to salinity stress by analysing primary and lateral root growth and fresh weight of plants grown under in vitro conditions in growth chambers. Even though NaCl is the most frequent used salinity tests, other salts (e.g. KCl, MgCl2) can be also evaluated by this method. Arabidopsis plants can be maintained for 15-20 days in these conditions, although effects on growth and biomass can be observed, depending on the used salt and concentration, within the first 10 days.
During the last years, improvement of bio-refinery technologies to process plant biomass into bio... more During the last years, improvement of bio-refinery technologies to process plant biomass into biofuel has led to an increased study and development of candidate biomass crops. The feasibility of using cellulosic fuels will be determined by the capacity to produce large amounts of reasonably priced feedstock without jeopardizing food security or the environment. Therefore, the combined supply of lignocelluloses from organic residues and bioenergy dedicated cropping systems are necessary to support renewable supply of cellulosic biofuel and other bio-commodities. A high-yield potential is a principal requirement for a biomass cropping system. Additionally, those yields must be preferably achieved with minimal costs and agricultural inputs, such as fertilizer and irrigation. Moreover, the effects on soil productivity are an important issue, since nutrients are surely removed from the field at every harvest. Our research line is focused on the study of regulatory networks involved in pl...
Plant physiology and biochemistry : PPB / Société française de physiologie végétale, 2011
Protease inhibitors from plants have been involved in defence mechanisms against pests and pathog... more Protease inhibitors from plants have been involved in defence mechanisms against pests and pathogens. Phytocystatins and trypsin/α-amylase inhibitors are two of the best characterized protease inhibitor families in plants. In barley, thirteen cystatins (HvCPI-1 to 13) and the BTI-CMe trypsin inhibitor have been previously studied. Their capacity to inhibit pest digestive proteases, and the negative in vivo effect caused by plants expressing these inhibitors on pests support the defence function of these proteins. Barley cystatins are also able to inhibit in vitro fungal growth. However, the antifungal effect of these inhibitors in vivo had not been previously tested. Moreover, their in vitro and in vivo effect on plant pathogenous bacteria is still unknown. In order to obtain new insights on this feature, in vitro assays were made against different bacterial and fungal pathogens of plants using the trypsin inhibitor BTI-CMe and the thirteen barley cystatins. Most barley cystatins an...
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