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Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Dicotyledones, Solanaceae, Spermatophyta, Biologie végétale, Plant biology, Biología vegetal, Choc thermique, Thermal shock, Choque térmico, Métabolisme, Metabolism, Metabolismo, Nicotiana, Polyamine, Poliamina, Proline, Prolina, Stress, Estrés, Heat stress, Polyamines, and Tobacco plants

The effect of heat stress on the accumulation of proline and on the level of polyamines (PAs) in tobacco plants was investigated. Responses to heat stress were compared in the upper and lower leaves and roots of tobacco plants that constitutively over-express a modified gene for the proline biosynthetic enzyme Δ1-pyrroline-5-carboxylate synthetase (PSCSF129A) and in the corresponding wild-type. In the initial phases of heat stress (after 2h at 40°C), the accumulation of proline increased in the wild type but slightly decreased in the transformants. The response to heat stress in proline-over-producing tobacco plants involved a transient increase in the levels of free and conjugated putrescine (Put) and in the levels of free spermidine (Spd), norspermidine (N-Spd) and spermine (Spm) after a 2-h lag phase, which correlated with stimulation of the activity of the corresponding biosynthetic enzymes. Diamine oxidase (DAO) activity increased in both plant genotypes, most significantly in the leaves of WT plants. Polyamine oxidase (PAO) activity increased in the roots of WT plants and decreased in the leaves and roots of the transformants. After 6 h of heat stress, proline accumulation was observed in the transformants, especially in the lower leaves; much more modest increase was observed in the WT plants. A decrease in the levels of free and conjugated Put coincided with down-regulation of the activity of ornithine decarboxylase and marked stimulation of DAO activity in the leaves and roots of the transformants. PAO activity increased in the roots of the transformants but decreased in the leaves. Conversely, in WT tobacco subjected to 6 h of heat stress, slight increases in free and conjugated PA levels were observed and the activity of DAO only increased in the roots; PAO activity did not change from the value observed during the initial phase of heat stress. 6 Hours' heat stress had no effect on the level of malondialdehyde (MDA; a product of lipid peroxidation), in the upper leaves of either genotype. After a recovery period (2 h at 25 °C), most of the studied parameters exhibited values comparable to those observed in untreated plants. The coordination of the proline and polyamine biosynthetic pathways during heat stress conditions is discussed.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Capparaceae, Dicotyledones, Spermatophyta, Antioxydant, Antioxidant, Antioxidante, Biologie végétale, Plant biology, Biología vegetal, Enzyme, Enzima, Peroxyde d'hydrogène, Hydrogen peroxide, Peróxido de hydrogeno, Stress hydrique, Water stress, Estrés hídrico, Sécheresse, Drought, Sequedad, Type C3, C3-Type, Tipo C3, Type C4, C4-Type, Tipo C4, Cleome gynandra, Antioxidant enzymes, C3 and C4, Cleome spinosa, and H2O2

Differences between antioxidant responses to drought in C3 and C4 plants are rather scanty. Even, we are not aware of any research on comparative ROS formation and antioxidant enzymes in C3 and C4 species differing in carboxylation pathway of same genus which would be useful to prevent other differences in plant metabolism. With this aim, relative shoot growth rate, relative water content and osmotic potential, hydrogen peroxide (H2O2) content and NADPH oxidase (NOX) activity, antioxidant defence system (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductase (GR) enzymes and their isoenzymes), CAT1 mRNA level, and lipid peroxidation in seedlings of Cleome spinosa (C3) and Cleome gynandra (C4) species of Cleome genus exposed to drought stress for 5 and 10 day (d) were comparatively investigated. Constitutive levels of antioxidant enzymes (except SOD) were consistently higher in C. spinosa than in C. gynandra under control conditions. CAT1 gene expression in C. spinosa was correlated with CAT activity but CAT1 gene expression in C. gynandra at 10 d did not show this correlation. Drought stress caused an increase in POX, CAT, APX and GR in both species. However, SOD activity was slightly decreased in C. gynandra while it was remained unchanged or increased on 5 and 10 d of stress in C. spinosa, respectively. Parallel to results of malon dialdehyde (MDA), H2O2 content was also remarkably increased in C. spinosa as compared to C. gynandra under drought stress. These results suggest that in C. spinosa, antioxidant defence system was insufficient to suppress the increasing ROS production under stress condition. On the other hand, in C. gynandra, although its induction was lower as compared to C. spinosa, antioxidant system was able to cope with ROS formation under drought stress.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Agronomie. Sciences du sol et productions vegetales, Agronomy. Soil science and plant productions, Génétique et amélioration des plantes d'intérêt économique, Genetics and breeding of economic plants, Amélioration et sélection: aspects fondamentaux et méthodologiques, Plant breeding: fundamental aspects and methodology, Applications du génie génétique, Genetic engineering applications, Angiospermae, Dicotyledones, Plante légumière, Vegetable crop, Hortalizas (plantas), Solanaceae, Spermatophyta, Biologie végétale, Plant biology, Biología vegetal, Chlorophylle, Chlorophyll, Clorofila, Criblage, Screening, Cernido, Facteur transcription, Transcription factor, Factor transcripción, Fluorescence, Fluorescencia, Lycopersicon esculentum, Plante transgénique, Transgenic plant, Planta transgénica, Résistance sécheresse, Drought resistance, Resistencia sequedad, Sécheresse, Drought, Sequedad, Tolérance, Tolerance, Tolerancia, Chlorophyll fluorescence, High-throughput screening, and Solanum lycopersicum

Drought stress is one of the most important factors that limit crop productivity worldwide. In order to obtain tomato plants with enhanced drought tolerance, we inserted the transcription factor gene ATHB-7 into the tomato genome. This gene was demonstrated earlier to be up-regulated during drought stress in Arabidopsis thaliana thus acting as a negative regulator of growth. We compared the performance of wild type and transgenic tomato line DTL-20, carrying ATHB-7 gene, under well-irrigated and water limited conditions. We found that transgenic plants had reduced stomatal density and stomatal pore size and exhibited an enhanced resistance to soil water deficit. We used the transgenic plants to investigate the potential of chlorophyll fluorescence to report drought tolerance in a simulated high-throughput screening procedure. Wild type and transgenic tomato plants were exposed to drought stress lasting 18 days. The stress was then terminated by rehydration after which recovery was studied for another 2 days. Plant growth, leaf water potential, and chlorophyll fluorescence were measured during the entire experimental period. We found that water potential in wild type and drought tolerant transgenic plants diverged around day 11 of induced drought stress. The chlorophyll fluorescence parameters: the non-photochemical quenching, effective quantum efficiency of PSII, and the maximum quantum yield of PSII photochemistry yielded a good contrast between wild type and transgenic plants from day 7, day 12, and day 14 of induced stress, respectively. We propose that chlorophyll fluorescence emission reports well on the level of water stress and, thus, can be used to identify elevated drought tolerance in high-throughput screens for selection of resistant genotypes.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Cruciferae, Dicotyledones, Plante expérimentale, Experimental plant, Planta experimental, Spermatophyta, Amélioration génétique, Genetic improvement, Enriquecimiento genético, Arabidopsis thaliana, Biologie végétale, Plant biology, Biología vegetal, Espèces réactives de l'oxygène, Reactive oxygen species, Especies reactivas del oxígeno, Halotolérance, Halotolerance, Halotolerancia, Mitochondrie, Mitochondria, Mitocondria, Résistance sel, Salt resistance, Resistencia sal, Surexpression génique, Gene overexpression, Sobreexpresión genética, Arabidopsis, Mitochondrion, PPR40, and Salt tolerance

Mitochondrial respiration is sensitive to environmental conditions and can be influenced by abiotic stress. Previously we described the Arabidopsis mitochondrial pentatricopeptide repeat domain protein PPR40, and showed that the stress hypersensitive ppr40-1 mutant is compromised in mitochondrial electron transport (Zsigmond et al., 2008) [20]. Overexpression of the PPR40 gene in Arabidopsis resulted in enhanced germination and superior plant growth in saline conditions. Respiration increased in PPR40 overexpressing plants during salt stress. Reduced amount of hydrogen peroxide, diminished lipid peroxidation, lower ascorbate peroxidase and superoxide dismutase activity accompanied salt tolerance. Proline accumulation was enhanced in the ppr40-1 mutant, but unaltered in the PPR40 overexpressing plants. Our data suggest that PPR40 can diminish the generation of reactive oxygen species by stabilizing the mitochondrial electron transport and protecting plants via reducing oxidative damage during stress.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Cruciferae, Dicotyledones, Plante expérimentale, Experimental plant, Planta experimental, Spermatophyta, Arabidopsis thaliana, Biologie végétale, Plant biology, Biología vegetal, Long terme, Long term, Largo plazo, Mutation, Mutación, Polyamine, Poliamina, Salinité, Salinity, Salinidad, Spermine, Espermina, Stress, Estrés, Polyamines, Salt stress, Thermospermine, and sos mutants

Polyamines (putrescine, spermidine and spermine) are traditionally implicated in the response of plants to environmental cues. Free spermine accumulation has been suggested as a particular feature of long-term salt stress, and in the model plant Arabidopsis thaliana the spermine synthase gene (AtSPMS) has been reported as inducible by abscisic acid (ABA) and acute salt stress treatments. With the aim to unravel the physiological role of free spermine during salinity, we analyzed polyamine metabolism in A. thaliana salt-hypersensitive sos mutants (salt overlay sensitive; sos1-1, sos2-1 and sos3-1), and studied the salt stress tolerance of the mutants in spermine and thermospermine synthesis (acl5-1, spms-1 and acl5-1/spms-1). Results presented here indicate that induction in polyamine metabolism is a SOS-independent response to salinity and is globally over-induced in a sensitive background. In addition, under long-term salinity, the mutants in the synthesis of spermine and thermospermine (acl5-1, spms-1 and double acl5-1/spms- 1) accumulated more Na+ and performed worst than WT in survival experiments. Therefore, support is given to a role for these higher polyamines in salt tolerance mechanisms.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Gramineae, Monocotyledones, Plante céréalière, Cereal crop, Planta cerealista, Spermatophyta, Zone subtropicale, Subtropical zone, Zona subtropical, Biologie végétale, Plant biology, Biología vegetal, Expression génique, Gene expression, Expresión genética, Modulation, Modulación, Métabolite, Metabolite, Metabolito, Métabolomique, Metabolomics, Metabolómica, Oryza sativa, Saccharose, Sucrose, Sacarosa, Salinité, Salinity, Salinidad, Sel, Salt, Sal, Stress, Estrés, Transport, Transporte, Metabolite profiling, Rice, Salt stress, and Sucrose transporter (OsSUT1)

A metabolic depletion syndrome was discovered at early vegetative stages in roots of salt sensitive rice cultivars after prolonged exposure to 100 mM NaCl. Metabolite profiling analyses demonstrate that this syndrome is part of the terminal stages of the rice salt response. The phenotype encompasses depletion of at least 30 primary metabolites including sucrose, glucose, fructose, glucose-6-P, fructose-6P, organic-and amino-acids. Based on these observations we reason that sucrose allocation to the root may modify the rice response to high salt. This hypothesis was tested using antisense lines of the salt responsive OsSUT1 gene in the salt sensitive Taipei 309 cultivar. Contrary to our expectations of a plant system impaired in one component of sucrose transport, we find improved gas exchange and photosynthetic performance as well as maintenance of sucrose levels in the root under high salinity. Two independent OsSUT1 lines with an antisense inhibition similar to the naturally occurring salt induced reduction of OsSUT1 gene expression showed these phenomena but not a more extreme antisense inhibition line. We investigated the metabolic depletion syndrome by metabolomic and physiological approaches and discuss our results with regard to the potential role of sucrose transporters and sucrose transport for rice salt acclimation.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Cruciferae, Dicotyledones, Métal lourd, Heavy metal, Metal pesado, Plante légumière, Vegetable crop, Hortalizas (plantas), Spermatophyta, Antioxydant, Antioxidant, Antioxidante, Assimilation, Asimilación, Azote, Nitrogen, Nitrógeno, Biologie végétale, Plant biology, Biología vegetal, Cadmium, Cadmio, Croissance, Growth, Crecimiento, Dose faible, Low dose, Dosis débil, Lepidium sativum, Mécanisation, Mechanization, Mecanización, Métabolisme, Metabolism, Metabolismo, Photosynthèse, Photosynthesis, Fotosíntesis, Soufre, Sulfur, Azufre, Antioxidants, and Garden cress

Metal contamination of soils has become a worldwide problem and great environmental threat, as these metals accumulate in soils and plants in excess, and enter the food chain. Increased cadmium (Cd) uptake from contaminated soils leads to altered plant metabolism and limits the crop productivity. The experimental crop, Lepidium sativum L (Garden Cress, Family: Brassicaceae) is a medicinally and economically important plant. An experiment was conducted to examine the effect of different concentrations of Cd (0, 25, 50 or 100 mg kg-1 soil) on the performance of L. sativum. Cd accumulation in roots and leaves (roots > leaves) increased with the increaseing Cd concentration in soil. High Cd concentration (100 mg Cd kg-1 soil) inhibited the leaf area and plant dry mass and significant decline in net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 (Ci), chlorophyll (Chl a, Chl b, total Chl) content, carbonic anhydrase (CA; E.C. 4.2.1.1) activity, nitrate reductase (NR; E.C. 1.6.6.1) activity and nitrogen (N) content was also observed. However, ATP-sulfurylase (ATP-S; EC. 2.7.7.4) activity, sulfur (S) content and activities of antioxidant enzymes such as superoxide dismutase (SOD; E.C. 1.15.1.1); catalase (CAT; E.C. 1.11.1.6); ascorbate peroxidase (APX; E.C. 1.11.1.11) and glutathione reductase (GR; E.C. 1.6.4.2) and glutathione (GSH) content were increased. Specifically, the decrease in NR activity and N content showed that Cd affects N metabolism negatively; whereas, the increase in ATP-S activity and S content suggests the up-regulation of S assimilation pathway for possible Cd tolerance in coordination with enhanced activities of antioxidant enzymes and GSH. High Cd concentration (100mg Cd kg-1 soil) perturbs the L. sativum growth by interfering with the photosynthetic machinery and disrupting the coordination between carbon, N and S metabolism. On the other hand, at low Cd concentration (25 mg Cd kg-1 soil) co-ordination of S and N metabolism complemented to the antioxidant machinery to protect the growth and photosynthesis of L. sativum plants.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Cruciferae, Dicotyledones, Enzyme, Enzima, Glycosyltransferases, Hexosyltransferases, Plante expérimentale, Experimental plant, Planta experimental, Spermatophyta, Transferases, 1,3-β-Glucan synthase, Altération, Alteration, Alteración, Arabidopsis thaliana, Biologie végétale, Plant biology, Biología vegetal, Callose, Calosa, Paroi cellulaire, Cell wall, Pared celular, Perméabilité cellulaire, Cell permeability, Permeabilidad celular, Tabac, Tobacco, Tabaco, Callose synthase, and Tobacco BY-2 cells

Callose is the major polysaccharide present in the callose wall of developing microspores and the growing pollen tube wall. It is also an essential component of other specialized cell walls and its synthesis can be induced by pathogen infection, wounding and environmental cues. Among the 12 callose synthase genes (CalS) present in the Arabidopsis genome, CalS5 plays the predominant role in the synthesis of the callose wall, callose plugs and pollen tube wall. When expressed as a GFP-tagged protein in cultured tobacco BY-2 cells, CalS5 was found to be present in the plasma membrane and the Golgi-related endomembranes. Unlike the cell plate-specific CalS1 isozyme, CalS5 was not concentrated to the cell plate at cytokinesis. Expression of CalS5 resulted in callose accumulation only in the cell wall of BY-2 cells. The fact that no callose was found in the endomembranes suggests that CalS5 is not functional in that compartment. These cells exhibited a decreased plasmolysis rate in hypotonic solutions and an increased cytolysis rate in hypertonic conditions. This study demonstrates that an artificial callose wall could be synthesized by expressing a callose synthase enzyme.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Phytopathologie. Zoologie agricole. Protection des cultures et des forets, Phytopathology. Animal pests. Plant and forest protection, Bactéries phytopathogènes, Bacterial plant pathogens, Angiospermae, Bactérie, Bacteria, Dicotyledones, Enterobacteriaceae, Phytopathogène, Plant pathogen, Fitopatógeno, Plante ligneuse, Woody plant, Planta leñosa, Rosaceae, Spermatophyta, Substance croissance végétal, Plant growth substance, Substancia crecimiento vegetal, Terpénoïde, Terpenoid, Terpenoide, Acide salicylique, Salicylic acid, Biologie végétale, Plant biology, Biología vegetal, Erwinia amylovora, Expression génique, Gene expression, Expresión genética, Génotype, Genotype, Genotipo, Infection, Infección, Malus, Modulation, Modulación, Pomme, Apple, Manzana, Sensibilité résistance, Sensitivity resistance, Sensibilidad resistencia, Acide jasmonique, Jasmonic acid, Acido jasmónico, Jasmonique acide ester méthyle, Jasmonic acid ester methyl, Acido jasmónico ester metilo, Jasmonique acide, DspA/E, Fire blight, and Methyl-jasmonate

Fire blight is a bacterial disease ofMaloideae caused by Erwinia amylovora (Ea). This necrogenic enterobacterium uses a type III secretion system (T3SS) to inject type III effectors into the plant cells to cause disease on its susceptible hosts, including economically important crops like apple and pear. The expressions of marker genes of the salicylic acid (SA) and jasmonic acid (JA) defense regulation pathways were monitored by RT-qPCR in leaves of two apple genotypes, one susceptible and one resistant, challenged with a wild type strain, a T3SS-deficient strain or water. The transcriptional data taken together with hormone level measurements indicated that the SA pathway was similarly induced in both apple genotypes during infection by Ea. On the contrary, the data clearly showed a strong T3SS-dependent down-regulation of the JA pathway in leaves of the susceptible genotype but not in those of the resistant one. Accordingly, methyl-jasmonate treated susceptible plants displayed an increased resistance to Ea. Bacterial mutant analysis indicated that JA manipulation by Eo mainly relies on the type III effector DspA/E. Taken together, our data suggest that the T3SS-dependent down-regulation of the JA pathway is a critical step in the infection process of Malus spp. by Ea.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Agronomie. Sciences du sol et productions vegetales, Agronomy. Soil science and plant productions, Génétique et amélioration des plantes d'intérêt économique, Genetics and breeding of economic plants, Sélection variétale. Amélioration spéciale, objectifs d'amélioration, Varietal selection. Specialized plant breeding, plant breeding aims, Angiospermae, Dicotyledones, Leguminosae, Légumineuse grain, Grain legume, Leguminosa grano, Plante légumière, Vegetable crop, Hortalizas (plantas), Spermatophyta, Biologie végétale, Plant biology, Biología vegetal, Cultivar traditionnel, Landrace(plant), Cultivar local, Graine, Seeds, Semillas, Lens culinaris, Marqueur, Marker, Marcador, Protéine réserve, Storage protein, Proteína reserva, Protéome, Proteome, Proteoma, Protéomique, Proteomics, Proteómica, Stress, Estrés, Landrace markers, Lens culinaris Medik, Seed, and Stress response

Unlike modern cultivars selected for their growth performances in specific environmental conditions, local landraces have a high genetic variability that is an important resource for plant breeding. Consequent to their high adaptation to different environmental conditions, these landraces may have evolved adaptive gene complexes To promote the survival of endangered lentil landraces, we previously investigated the genetic relationship between two ancient landraces cultivated in the Molise region (Capracotta and Conca Casale, south-central Italy) and widely spread commercial varieties using an integrated approach consisting of morphological, DNA and protein characterization. In the present study, we used a proteomic approach to compare the mature seed proteomes of the Capracotta and Conca Casale lentil landraces. Multivariate analysis of 145 differentially expressed protein spots demonstrated that 52 proteins are required to discriminate among the two landraces. Therefore, these 52 proteins can be considered landrace markers. The results of this study show that the combination of proteomics and multivariate analysis can be used to identify physiological and/or environmental markers, and is thus a powerful tool that complements the analysis of biodiversity in plant ecotypes.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Gramineae, Monocotyledones, Plante sucrière, Sugar plant, Planta azucarera, Spermatophyta, Analyse biochimique, Biochemical analysis, Análisis bioquímico, Antioxydant, Antioxidant, Antioxidante, Biologie végétale, Plant biology, Biología vegetal, Canne à sucre, Sugar cane, Caña de azúcar, DNA complémentaire, Complementary DNA, DNA complementario, Expression génique, Gene expression, Expresión genética, Gène candidat, Candidate gene, Gen candidato, Saccharum officinarum, Salinité, Salinity, Salinidad, Stress, Estrés, Antioxidants, Candidate genes, Plant responses, Salt stress, and cDNA-SSH

Sugarcane productivity is worldwide subjected to increasing environmental constraints, predominantly to drought and salinity owing to their high magnitude of impact and wide distribution. The present study provides insights into the knowledge of sugarcane responses at germination, tillering and respective recovery stages to high salinity at physio-biochemical and molecular level. Our results indicated that there was a negative relationship between catalase, and peroxidase activity with lipid peroxidation and SOD activity. Increase in MDA and SOD levels at the earlier stages of stress and later increase in CAT and POD levels on prolonged stress was evidenced. Thus they can be used as indicators of stress for sugarcane plants facing unfavourable environmental conditions. At molecular level, we have identified 137 salinity tolerant candidate cDNAs from sugarcane by cDNA-SSH, representing 20% of which are novel sugarcane genes. These unique sequences, never reported elsewhere to be stress related and might provide further understanding on perception, response and adaptations mechanisms of the non-model plant like sugarcane to salinity stress and will be potential candidates for manipulating salt tolerant trait.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Dicotyledones, Leguminosae, Légumineuse grain, Grain legume, Leguminosa grano, Plante protéagineuse, High protein crop, Planta proteaginosa, Spermatophyta, Aluminium, Aluminio, Apex, Biologie végétale, Plant biology, Biología vegetal, Croissance, Growth, Crecimiento, Elongation, Elongación, Modification structure, Structure modification, Modificación estructural, Pisum sativum, Racine, Root, Raíz, Stress oxydatif, Oxidative stress, Estrés oxidativo, Toxicité, Toxicity, Toxicidad, Al toxicity, Pisum sativum L, Recovery, Root elongation, and Structural changes

Al inhibits root apex elongation with concomitant morphological injuries such as ruptures punctuated by the regions stained with Evans blue. The recovery can be investigated by transfer of Al-injured roots to a solution lacking Al. In the Al-injured root apex, superoxide anion, H2O2, Al, and lignin accumulate. During the recovery process, the central cylinder elongates leaving the region stained with Evans blue without marked disappearance. The obvious function of the region is not clear but may trigger the elongation of central cylinder during the recovery process. Thus the function of the region stained with Evans blue might be derived from the programmed cell-like idea. Oxidative stress concerns events induced under Al toxicity and the recovery process. The superoxide anion is primarily formed by plasma membrane-associated NADPH oxidase and is dismuted to H2O2 and O2 by superoxide dismutase. H2O2 provides the electrons for the polymerization of phenolics to lignin, which causes the stiffening of the cell wall. The distortion of the cell wall caused by lignin may induce the breaking and tearing of cells, which results in the formation of ruptures at the rhizodermis and outer cortex layers. The production of superoxide anion, H2O2, and lignin was reduced during the recovery process and thereby the elongation of the central cylinder may be induced.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Agronomie. Sciences du sol et productions vegetales, Agronomy. Soil science and plant productions, Génétique et amélioration des plantes d'intérêt économique, Genetics and breeding of economic plants, Angiospermae, Compositae, Dicotyledones, Enzyme, Enzima, Plante légumière, Vegetable crop, Hortalizas (plantas), Spermatophyta, Biologie végétale, Plant biology, Biología vegetal, Biosynthèse, Biosynthesis, Biosíntesis, Carte génétique, Genetic mapping, Mapa genético, Cynara cardunculus, Gène, Gene, Gen, Lactone, Lactona, Sesquiterpène, Sesquiterpenes, Sesquiterpeno, Synthase, Terpène, Terpene, Terpeno, (+)-Germacrene A, Cynaropicrin, Sesquiterpene lactones, and Terpene synthase

Globe artichoke (Cynara cardunculus var. scolymus L, Asteraceae) is a perennial crop traditionally consumed as a vegetable in the Mediterranean countries and rich in nutraceutically and pharmaceutically active compounds, including phenolic and terpenoid compounds. Its bitter taste is caused by its high content of sesquiterpene lactones (STLs), such as cynaropicrin. The biosynthetic pathway responsible for STL biosynthesis in globe artichoke is unknown, but likely proceeds through germacrene A, as has been shown for other Asteraceae species. Here, we investigated the accumulation of cynaropicrin in different tissues of globe artichoke, and compared it to accumulation of phenolic compounds. Cynaropicrin concentration was highest in old leaves. A putative germacrene A synthase (GAS) gene was identified in a set of ∼19,000 globe artichoke unigenes. When heterologously expressed in Escherichia coli, the putative globe artichoke GAS converted farnesyl diphosphate (FPP) into (+)-germacrene A. Among various tissues assayed, the level of globe artichoke GAS expression was highest in mature (six week old) leaves. A sequence polymorphism within a mapping population parent allowed the corresponding GAS gene to be positioned on a genetic map. This study reports the isolation, expression and mapping of a key gene involved in STL biosynthesis in C. cardunculus. This is a good basis for further investigation of this pathway.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Gramineae, Monocotyledones, Métal lourd, Heavy metal, Metal pesado, Plante céréalière, Cereal crop, Planta cerealista, Spermatophyta, Biologie végétale, Plant biology, Biología vegetal, Cadmium, Cadmio, Croissance, Growth, Crecimiento, Cycle cellulaire, Cell cycle, Ciclo celular, Inhibiteur croissance, Growth inhibitor, Inhibidor crecimiento, Inhibition, Inhibición, Modification posttraductionnelle, Posttranslational modification, Modificación postraduccional, Oxydation, Oxidation, Oxidación, Protéine, Protein, Proteína, Racine, Root, Raíz, Stade juvénile plante, Plant juvenile growth stage, Estado juvenil planta, Stress oxydatif, Oxidative stress, Estrés oxidativo, Toxicité, Toxicity, Toxicidad, Triticum aestivum, and Root growth inhibition

Abiotic stress is greatly associated with plant growth inhibition and redox cell imbalance. In the present work, we have investigated in which way oxidative posttranslational modifications (PTM) of proteins related to cell cycle may be implicated in post-germinative root growth reduction caused by cadmium, by methyl viologen (MV) and by hydrogen peroxide (H2O2) in wheat seedlings. Although cadmium is considered a redox inactive metal, reactive oxygen species were detected in the apex root of metal-treated seedlings. Oxidative stress hastened cells displacement from the cell division zone to elongation/differentiation zone, resulting in a shortened meristem. The number of cells in the proliferation zone was lower after MV, H2O2 and 10 μM Cd2+ treatments compared to control. All treatments increased protein carbonylation. Although no modification in total Ub-conjugated proteins was detected, oxidative treatments reduced cyclin D and CDKA protein ubiquitination, concomitantly with a decrease in expression of cyclin D/CDKA/Rb/E2F-regulated genes. We postulate that ROS and oxidative PTM could be part of a general mechanism, specifically affecting G1/S transition and progression through S phase. This would rapidly block cell cycle progression and would allow the cellular defence system to be activated.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Gramineae, Monocotyledones, Plante céréalière, Cereal crop, Planta cerealista, Spermatophyta, Analyse quantitative, Quantitative analysis, Análisis cuantitativo, Biologie végétale, Plant biology, Biología vegetal, Germination, Germinación, Imbibition, Imbibición, Protéomique, Proteomics, Proteómica, Zea mays, Corps lipidique, Oil body, Cuerpo lipídico, Maize, Proteomic, and Scutellum

Oil bodies (OBs) were purified from the scutellum of mature maize embryos and from embryos 2 days after imbibition and their associated proteins were extracted and separated by 2-DE. Eighteen proteins were shown to be differentially accumulated, thirteen showed a higher accumulation in mature scutellum and five were highly accumulated in the germinating scutellum. Proteins were identified using LC―MS/MS. Besides previously known oil body protein oleosin, other proteins were identified in this study. Among accumulated proteins during imbibition are prohibitin 2, stress-inducible membrane pore protein Tim17 and manganese superoxide dismutase. Among the proteins whose amount decreases during imbibition are cupin 2, two different protein disulfide isomerases, a triosephosphate isomerase, a class IV heat shock protein, the embryonic protein DC-8, the 60S ribosomal protein P0, a nucleoside-diphosphate kinase, and a rubber elongation factor protein. Some of the identified proteins were previously located in organelles other than oil bodies, suggesting that OBs may interact with these organelles. We also suggest that OBs may act as transient storage depots for proteins that are temporally in excess.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Facteur milieu, Environmental factor, Factor medio, Gramineae, Monocotyledones, Plante herbacée, Herbaceous plant, Planta herbácea, Spermatophyta, Biologie végétale, Plant biology, Biología vegetal, Facteur abiotique, Abiotic factor, Factor abiótico, Facteur transcription, Transcription factor, Factor transcripción, Leucine, Leucina, Oryza, Résistance sécheresse, Drought resistance, Resistencia sequedad, Stress, Estrés, Abiotic stress, Rice, and bZIP transcription factor

Abiotic stress has been shown to limit the growth, development, and productivity of crops. Here, we characterized the function of a rice bZIP transcription factor OsbZIP16 in drought stress. Expression of Os6ZIP16 was dramatically induced under drought conditions. Transient expression and transactivation assays demonstrated that OsbZIP16 was localized in the nucleus and had transactivation activity. At both the seedling and tillering stages, transgenic rice plants overexpressing OsbZIP16 exhibited significantly improved drought resistance, which was positively correlated with the observed expression levels of OsbZIP16. Representative downstream drought-inducible genes were observed to have significantly higher expression levels in transgenic rice plants than in the wild type plants under drought conditions. OsbZIP16 was shown to be induced by exogenous ABA treatment, while overexpression of OsbZIP16 was observed to make transgenic plants more sensitive to ABA than wild type plants were. Transcriptome analysis identified a number of differentially expressed genes between wild type plants and plants overexpressing OsbZIP16, many of which are involved in stress response according to their gene ontologies. Overall, our findings suggest that OsbZIP16 positively regulates drought resistance in rice.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Dicotyledones, Plante légumière, Vegetable crop, Hortalizas (plantas), Solanaceae, Spermatophyta, Antioxydant, Antioxidant, Antioxidante, Basse température, Low temperature, Baja temperatura, Biologie végétale, Plant biology, Biología vegetal, Feuille végétal, Plant leaf, Hoja vegetal, Lycopersicon esculentum, Photoinhibition, Fotoinhibición, Photosynthèse, Photosynthesis, Fotosíntesis, Stress, Estrés, Tomate, Tomato, Température nocturne, Night temperature, Temperatura nocturna, Antioxidant system, Low night temperature, and Recovery

The effects of low night temperature (LNT, i.e., 9 and 6°C) stress and rewarming (15 °C night temperature) on the photosynthesis, photosystems I and II (PSI and PSII), and antioxidant system of tomato leaves were studied. The results showed that 9 d of LNT treatment led to an irreversible reduction in the photosynthetic rate. This reduction was accompanied by stomatal limitation of CO2 supply and significant decline in ribulose-1,5-bisphosphate carboxylase/oxygenase activity at the transcription level, as well as sucrose accumulation. LNT treatment induced the reversible photoinhibition of PSII, decreased PSII activity, increased the photochemical yield of PSI Y(I), and markedly caused the acceptor side limitation of PSI. This finding was reflected by the higher value of Y( NA) in the treated plants than in the control. At the same time, a downregulation of electron transport for photosynthetic carbon reduction under LNT was mostly compensated by Ja(O2-dependent) driven by the water-water cycle.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Agronomie. Sciences du sol et productions vegetales, Agronomy. Soil science and plant productions, Génétique et amélioration des plantes d'intérêt économique, Genetics and breeding of economic plants, Angiospermae, Gramineae, Monocotyledones, Plante céréalière, Cereal crop, Planta cerealista, Spermatophyta, Aluminium, Aluminio, Biologie végétale, Plant biology, Biología vegetal, Caractère agronomique, Agronomic character, Carácter agronómico, Gène, Gene, Gen, Locus quantitatif, Quantitative trait loci, Locus cuantitativo, Microréseau, Microarray, Microarreglo, Phytotoxicité, Phytotoxicity, Fitotoxicidad, Sol acide, Acid soil, Suelo ácido, Tolérance, Tolerance, Tolerancia, Zea mays, Aluminum, and QTL

The presence of aluminum (Al) is one of the main factors limiting crop yield in Brazil and worldwide. Plant responses to Al are complex, and the use of techniques such as microarrays can facilitate their comprehension. In a previous work, we evaluated the transcriptome of two maize lines, Cat100-6 and S1587-17, after growing the plants for 1 or 3 days in acid soil (pH 4.1) or alkaline soil with Ca(OH)2 (pH 5.5), and we identified genes that likely contribute to Al tolerance. The mapping of these genes to the chromosomes allowed the identification of the genes that are localized in maize QTLs previously reported in the literature as associated with the tolerant phenotype. We were able to map genes encoding proteins possibly involved with acid soil tolerance, such as the ones encoding an RNA binding protein, a protease inhibitor, replication factors, xyloglucan endotransglycosylase and cyclins, inside QTLs known to be important for the Al-tolerant phenotype.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Cruciferae, Dicotyledones, Plante expérimentale, Experimental plant, Planta experimental, Spermatophyta, Arabidopsis thaliana, Arbre phylogénétique, Phylogenetic tree, Arbol filogenético, Biologie végétale, Plant biology, Biología vegetal, Duplication, Duplicación, Développement, Development, Desarrollo, Gène, Gene, Gen, Mutation, Mutación, Protéine membranaire, Membrane protein, Proteína membranar, Arabidopsis, Gene duplication, and tet1/trn2 mutant

Tetraspanins represent a four-transmembrane protein superfamily with a conserved structure and amino acid residues that are present in mammals, insects, fungi and plants. Tetraspanins interact with each other or with other membrane proteins to form tetraspanin-enriched microdomains that play important roles in development, pathogenesis and immune responses via facilitating cell-cell adhesion and fusion, ligand binding and intracellular trafficking. Here, we emphasize evolutionary aspects within the plant kingdom based on genomic sequence information. A phylogenetic tree based on 155 tetraspanin genes of 11 plant species revealed ancient and fast evolving clades. Tetraspanins were only present in multicellular plants, were often duplicated in the plant genomes and predicted by the electronic Fluorescent Pictograph for gene expression analysis to be either functionally redundant or divergent. Tetraspanins contain a large extracellular loop with conserved cysteines that provide the binding sites for the interactions. The Arabidopsis thaliana TETRASPANIN1/TORNADO2/EKEKO has a function in leaf and root patterning and TETRASPANIN3 was identified in the plasmodesmatal proteome, suggesting a role in cell-cell communication during plant development.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Cell biology, histology, Biologie cellulaire, histologie, Plant biology and physiology, Biologie et physiologie végétales, Biotechnology, Biotechnologies, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Angiospermae, Compositae, Dicotyledones, Plante médicinale, Medicinal plant, Planta medicinal, Spermatophyta, Amplification, Amplificación, Apex, Artemisia annua, Artémisinine, Artemisinin, Artemisinina, Biologie végétale, Plant biology, Biología vegetal, Biosynthèse, Biosynthesis, Biosíntesis, Expression génique, Gene expression, Expresión genética, Fixation, Fijación, Laser, Láser, Microdissection, Microdisección, Métabolisme, Metabolism, Metabolismo, RNA, Terpène, Terpene, Terpeno, Trichome, Tricoma, Artemisinin biosynthesis, LMPC, Trichomes, and qPCR

The aim of this project was to evaluate the effect of fixation on plant material prior to Laser Microdissection and Pressure Catapulting (LMPC) and to identify an appropriate method for preserving good RNA quality after cell isolation. Therefore, flower buds from Artemisia annua L were exposed to either the fixative formaldehyde or a non-fixative buffer prior to cell isolation by LMPC. Proteinase K was used after cell isolation from fixed plant tissue, in an attempt to improve the RNA yield. The ability to detect gene expression using real-time quantitative PCR with or without previous amplification of RNA from cells isolated by LMPC was also evaluated. Conclusively, we describe a new technique, without fixation, enabling complete isolation of intact glandular secretory trichomes and specific single trichome cells of A. annua. This method is based on LMPC and preserves good RNA quality for subsequent RNA expression studies of both whole trichomes, apical and sub-apical cells from trichomes of A. annua. Using this method, expression of genes of terpene metabolism was studied by real-time quantitative PCR. Expression of genes involved in artemisinin biosynthesis was observed in both apical and sub-apical cells.