Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11846
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Item An L,L- diaminopimelate aminotransferase mutation leads to metabolic shifts and growth inhibition in Arabidopsis(Journal of Experimental Botany, 2018-12-01) Cavalcanti, João Henrique F.; Kirma, Menny; Barros, Jessica A. S.; Quinhones, Carla G.S.; Pereira- Lima, Ítalo A.; Obata, Toshihiro; Nunes- Nesi, Adriano; Galili, Gad; Fernie, Alisdair R.; Avin- Wittenberg, Tamar; Araújo, Wagner L.Lysine (Lys) connects the mitochondrial electron transport chain to amino acid catabolism and the tricarboxylic acid cycle. However, our understanding of how a deficiency in Lys biosynthesis impacts plant metabolism and growth remains limited. Here, we used a previously characterized Arabidopsis mutant (dapat) with reduced activity of the Lys biosynthesis enzyme L,L-diaminopimelate aminotransferase to investigate the physiological and metabolic impacts of impaired Lys biosynthesis. Despite displaying similar stomatal conductance and internal CO2 concentration, we observed reduced photosynthesis and growth in the dapat mutant. Surprisingly, whilst we did not find differences in dark respiration between genotypes, a lower storage and consumption of starch and sugars was observed in dapat plants. We found higher protein turnover but no differences in total amino acids during a diurnal cycle in dapat plants. Transcriptional and two-dimensional (isoelectric focalization/SDS-PAGE) proteome analyses revealed alterations in the abundance of several transcripts and proteins associated with photosynthesis and photorespiration coupled with a high glycine/serine ratio and increased levels of stress-responsive amino acids. Taken together, our findings demonstrate that biochemical alterations rather than stomatal limitations are responsible for the decreased photosynthesis and growth of the dapat mutant, which we hypothesize mimics stress conditions associated with impairments in the Lys biosynthesis pathway.Item Modifications in organic acid profiles during fruit development and ripening: correlation or causation?(Frontiers in Plant Science, 2018-11) Batista- Silva, Willian; Nascimento, Vitor L.; Medeiros, David B.; Nunes- Nesi, Adriano; Ribeiro, Dimas M.; Zsögön, Agustín; Araújo, Wagner L.The pivotal role of phytohormones during fruit development and ripening is considered established knowledge in plant biology. Perhaps less well-known is the growing body of evidence suggesting that organic acids play a key function in plant development and, in particular, in fruit development, maturation and ripening. Here, we critically review the connection between organic acids and the development of both climacteric and non-climacteric fruits. By analyzing the metabolic content of different fruits during their ontogenetic trajectory, we noticed that the content of organic acids in the early stages of fruit development is directly related to the supply of substrates for respiratory processes. Although different organic acid species can be found during fruit development in general, it appears that citrate and malate play major roles in this process, as they accumulate on a broad range of climacteric and non-climacteric fruits. We further highlight the functional significance of changes in organic acid profile in fruits due to either the manipulation of fruit-specific genes or the use of fruit-specific promoters. Despite the complexity behind the fluctuation in organic acid content during fruit development and ripening, we extend our understanding on the importance of organic acids on fruit metabolism and the need to further boost future research. We suggest that engineering organic acid metabolism could improve both qualitative and quantitative traits of crop fruits.Item Ethylene coordinates seed germination behavior in response to low soil pH in Stylosanthes humilis(Plant and Soil, 2018-04) Ribeiro, Ricardo P.; Costa, Lucas C.; Medina, Eduardo F.; Araújo, Wagner L.; Zsögön, Agustín; Ribeiro, Dimas M.Stylosanthes humilis is known to exhibit high persistence in acid soils, however, how low soil pH controls seed germination as well as root and hypocotyl growth remains unknown. This study was carried out to evaluate the hormonal and metabolic alterations induced by low soil pH on seed germination behavior of S. humilis.Seeds of S. humilis were sown in acid soil samples or sand soaked in buffer solution with pH ranging from 4.0 to 7.0. Concentrations of indole-3-acetic acid, ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), primary metabolite profile and final seed germination were evaluated after four days.Low soil pH led to increased final seed germination, concomitantly with higher root penetration into the soil as well as higher ACC and ethylene production by seedlings. Treatment with the ethylene biosynthesis inhibitor L-α-(2-aminoethoxyvinyl)-glycine (AVG) greatly reduced final seed germination under acidic conditions. Final seed germination of seeds treated with AVG was increased by exogenous ethylene application in a dose-dependent manner. Furthermore, low soil pH promoted distinct changes in IAA concentrations, and in carbon and nitrogen metabolism in hypocotyl and roots.Low soil pH increases the final germination of S. humilis seeds through alterations in ethylene metabolism, allowing root penetration into the soil.Item Can stable isotope mass spectrometry replace radiolabelled approaches in metabolic studies?(Plant Science, 2016-05-14) Silva, Willian Batista; Daloso, Danilo M.; Fernie, Alisdair R.; Nunes-Nesi, Adriano; Araújo, Wagner L.Metabolic pathways and the key regulatory points thereof can be deduced using isotopically labelled substrates. One prerequisite is the accurate measurement of the labeling pattern of targeted metabolites. The subsequent estimation of metabolic fluxes following incubation in radiolabelled substrates has been extensively used. Radiolabelling is a sensitive approach and allows determination of total label uptake since the total radiolabel content is easy to detect. However, the incubation of cells, tissues or the whole plant in a stable isotope enriched environment and the use of either mass spectrometry or nuclear magnetic resonance techniques to determine label incorporation within specific metabolites offers the possibility to readily obtain metabolic information with higher resolution. It additionally also offers an important complement to other post-genomic strategies such as metabolite profiling providing insights into the regulation of the metabolic network and thus allowing a more thorough description of plant cellular function. Thus, although safety concerns mean that stable isotope feeding is generally preferred, the techniques are in truth highly complementary and application of both approaches in tandem currently probably provides the best route towards a comprehensive understanding of plant cellular metabolism.Item Natural genetic variation for morphological and molecular determinants of plant growth and yield(Journal of Experimental Botany, 2016-03-24) Nunes-Nesi, Adriano; Nascimento, Vitor de Laia; Silva, Franklin Magnum de Oliveira; Zsögön, Agustin; Araújo, Wagner L.; Sulpice, RonanThe rates of increase in yield of the main commercial crops have been steadily falling in many areas worldwide. This generates concerns because there is a growing demand for plant biomass due to the increasing population. Plant yield should thus be improved in the context of climate change and decreasing natural resources. It is a major challenge which could be tackled by improving and/or altering light-use efficiency, CO2 uptake and fixation, primary metabolism, plant architecture and leaf morphology, and developmental plant processes. In this review, we discuss some of the traits which could lead to yield increase, with a focus on how natural genetic variation could be harnessed. Moreover, we provide insights for advancing our understanding of the molecular aspects governing plant growth and yield, and propose future avenues for improvement of crop yield. We also suggest that knowledge accumulated over the last decade in the field of molecular physiology should be integrated into new ideotypes.Item Exploring natural variation of photosynthetic, primary metabolism and growth parameters in a large panel of Capsicum chinense accessions(Planta, 2015-05-26) Rosado-Souza, Laise; Scossa, Federico; Chaves, Izabel S.; Kleessen, Sabrina; Salvador, Luiz F. D.; Milagre, Jocimar C.; Finger, Fernando; Bhering, Leonardo L.; Sulpice, Ronan; Araújo, Wagner L.; Nikoloski, Zoran; Fernie, Alisdair R.; Nunes-Nesi, AdrianoDiversity of accessions within the same species provides an alternative method to identify physiological and metabolic traits that have large effects on growth regulation, biomass and fruit production. Here, we investigated physiological and metabolic traits as well as parameters related to plant growth and fruit production of 49 phenotypically diverse pepper accessions of Capsicum chinense grown ex situ under controlled conditions. Although single-trait analysis identified up to seven distinct groups of accessions, working with the whole data set by multivariate analyses allowed the separation of the 49 accessions in three clusters. Using all 23 measured parameters and data from the geographic origin for these accessions, positive correlations between the combined phenotypes and geographic origin were observed, supporting a robust pattern of isolation-by-distance. In addition, we found that fruit set was positively correlated with photosynthesis-related parameters, which, however, do not explain alone the differences in accession susceptibility to fruit abortion. Our results demonstrated that, although the accessions belong to the same species, they exhibit considerable natural intraspecific variation with respect to physiological and metabolic parameters, presenting diverse adaptation mechanisms and being a highly interesting source of information for plant breeders. This study also represents the first study combining photosynthetic, primary metabolism and growth parameters for Capsicum to date.Item The genetic architecture of photosynthesis and plant growth-related traits in tomato(Plant, Cell & Environment, 2018-01-12) Silva, Franklin Magnum de Oliveira; Lichtenstein, Gabriel; Alseekh, Saleh; Rosado-Souza, Laise; Conte, Mariana; Seguiyama, Vanessa Fuentes; Lira, Bruno Silvestre; Fanourakis, Dimitrios; Usadel, Björn; Bhering, Leonardo Lopes; DaMatta, Fábio M.; Sulpice, Ronan; Araújo, Wagner L.; Rossi, Magdalena; Setta, Nathalia de; Fernie, Alisdair R.; Carrari, Fernando; Nunes‐Nesi, AdrianoTo identify genomic regions involved in the regulation of fundamental physiological processes such as photosynthesis and respiration, a population of Solanum pennellii introgression lines was analyzed. We determined phenotypes for physiological, metabolic, and growth related traits, including gas exchange and chlorophyll fluorescence parameters. Data analysis allowed the identification of 208 physiological and metabolic quantitative trait loci with 33 of these being associated to smaller intervals of the genomic regions, termed BINs. Eight BINs were identified that were associated with higher assimilation rates than the recurrent parent M82. Two and 10 genomic regions were related to shoot and root dry matter accumulation, respectively. Nine genomic regions were associated with starch levels, whereas 12 BINs were associated with the levels of other metabolites. Additionally, a comprehensive and detailed annotation of the genomic regions spanning these quantitative trait loci allowed us to identify 87 candidate genes that putatively control the investigated traits. We confirmed 8 of these at the level of variance in gene expression. Taken together, our results allowed the identification of candidate genes that most likely regulate photosynthesis, primary metabolism, and plant growth and as such provide new avenues for crop improvement.Item Impaired malate and fumarate accumulation due the mutation of tonoplast dicarboxylate transporter(Plant Physiology, 2017-09-20) Medeiros, David B.; Barros, Kallyne; Barros, Jessica AS; Omena-Garcia, Rebeca P; Detmann, Kelly C; Silva, Willian Batista; DaMatta, Fabio; Nunes-Nesi, Adriano; Araújo, Wagner L.; Arrivault, Stéphanie; Sanglard, Lilian Vincis Pereira; Daloso, Danilo M.; Fernie, Alisdair R.Malate is a central metabolite involved in a multiplicity of plant metabolic pathways, being associated with mitochondrial metabolism and playing significant roles n stomatal movements. Vacuolar malate transport has been characterized at the molecular level and is performed by at least one carrier protein and two channels in Arabidopsis vacuoles. The absence of the Arabidopsis thaliana tonoplast Dicarboxylate Transporter (tDT) in tdt knockout mutant was previously associated with an impaired accumulation of malate and fumarate in leaves. Here, we investigated the consequences of this lower accumulation on stomatal behaviour and photosynthetic capacity as well as ts putative metabolic impacts. Neither the stomatal conductance (g s ) nor the kinetic responses to dark, light or high CO 2 were highly affected in tdt plants. In addition, we did not observe any impact on stomatal aperture following incubation with either bscisic acid (ABA), malate or citrate. Further, an effect on photosynthetic capacity was not observed in the mutant lines. However, leaf mitochondrial metabolism was affected in the tdt plants. Levels of the intermediates of the tricarboxylic acid cycle were altered and increases in both light and dark respiration were observed. We conclude that manipulation of the tonoplastic organic acid transporter impacted mitochondrial metabolism, while the overall stomatal and photosynthetic capacity were unaffected.