@article{RibeiroAraujoFernieetal.2012, author = {Ribeiro, Dimas M. and Araujo, Wagner L. and Fernie, Alisdair R. and Schippers, Jos H. M. and M{\"u}ller-R{\"o}ber, Bernd}, title = {Action of Gibberellins on growth and metabolism of arabidopsis plants Associated with high concentration of carbon dioxide}, series = {Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants}, volume = {160}, journal = {Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants}, number = {4}, publisher = {American Society of Plant Physiologists}, address = {Rockville}, issn = {0032-0889}, doi = {10.1104/pp.112.204842}, pages = {1781 -- 1794}, year = {2012}, abstract = {Although the positive effect of elevated CO2 concentration [CO2] on plant growth is well known, it remains unclear whether global climate change will positively or negatively affect crop yields. In particular, relatively little is known about the role of hormone pathways in controlling the growth responses to elevated [CO2]. Here, we studied the impact of elevated [CO2] on plant biomass and metabolism in Arabidopsis (Arabidopsis thaliana) in relation to the availability of gibberellins (GAs). Inhibition of growth by the GA biosynthesis inhibitor paclobutrazol (PAC) at ambient [CO2] (350 mu mol CO2 mol(-1)) was reverted by elevated [CO2] (750 mu mol CO2 mol(-1)). Thus, we investigated the metabolic adjustment and modulation of gene expression in response to changes in growth of plants imposed by varying the GA regime in ambient and elevated [CO2]. In the presence of PAC (low-GA regime), the activities of enzymes involved in photosynthesis and inorganic nitrogen assimilation were markedly increased at elevated [CO2], whereas the activities of enzymes of organic acid metabolism were decreased. Under ambient [CO2], nitrate, amino acids, and protein accumulated upon PAC treatment; however, this was not the case when plants were grown at elevated [CO2]. These results suggest that only under ambient [CO2] is GA required for the integration of carbohydrate and nitrogen metabolism underlying optimal biomass determination. Our results have implications concerning the action of the Green Revolution genes in future environmental conditions.}, language = {en} } @article{RibeiroAraujoFernieetal.2012, author = {Ribeiro, Dimas M. and Araujo, Wagner L. and Fernie, Alisdair R. and Schippers, Jos H. M. and M{\"u}ller-R{\"o}ber, Bernd}, title = {Translatome and metabolome effects triggered by gibberellins during rosette growth in Arabidopsis}, series = {Journal of experimental botany}, volume = {63}, journal = {Journal of experimental botany}, number = {7}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0022-0957}, doi = {10.1093/jxb/err463}, pages = {2769 -- 2786}, year = {2012}, abstract = {Although gibberellins (GAs) are well known for their growth control function, little is known about their effects on primary metabolism. Here the modulation of gene expression and metabolic adjustment in response to changes in plant (Arabidopsis thaliana) growth imposed on varying the gibberellin regime were evaluated. Polysomal mRNA populations were profiled following treatment of plants with paclobutrazol (PAC), an inhibitor of GA biosynthesis, and gibberellic acid (GA(3)) to monitor translational regulation of mRNAs globally. Gibberellin levels did not affect levels of carbohydrates in plants treated with PAC and/or GA(3). However, the tricarboxylic acid cycle intermediates malate and fumarate, two alternative carbon storage molecules, accumulated upon PAC treatment. Moreover, an increase in nitrate and in the levels of the amino acids was observed in plants grown under a low GA regime. Only minor changes in amino acid levels were detected in plants treated with GA(3) alone, or PAC plus GA(3). Comparison of the molecular changes at the transcript and metabolite levels demonstrated that a low GA level mainly affects growth by uncoupling growth from carbon availability. These observations, together with the translatome changes, reveal an interaction between energy metabolism and GA-mediated control of growth to coordinate cell wall extension, secondary metabolism, and lipid metabolism.}, language = {en} } @misc{BeninaRibeiroGechevetal.2015, author = {Benina, Maria and Ribeiro, Dimas Mendes and Gechev, Tsanko S. and M{\"u}ller-R{\"o}ber, Bernd and Schippers, Jos H. M.}, title = {A cell type-specific view on the translation of mRNAs from ROS-responsive genes upon paraquat treatment of Arabidopsis thaliana leaves}, series = {Plant, cell \& environment : cell physiology, whole-plant physiology, community physiology}, volume = {38}, journal = {Plant, cell \& environment : cell physiology, whole-plant physiology, community physiology}, number = {2}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0140-7791}, doi = {10.1111/pce.12355}, pages = {349 -- 363}, year = {2015}, abstract = {Oxidative stress causes dramatic changes in the expression levels of many genes. The formation of a functional protein through successful mRNA translation is central to a coordinated cellular response. To what extent the response towards reactive oxygen species (ROS) is regulated at the translational level is poorly understood. Here we analysed leaf- and tissue-specific translatomes using a set of transgenic Arabidopsis thaliana lines expressing a FLAG-tagged ribosomal protein to immunopurify polysome-bound mRNAs before and after oxidative stress. We determined transcript levels of 171 ROS-responsive genes upon paraquat treatment, which causes formation of superoxide radicals, at the whole-organ level. Furthermore, the translation of mRNAs was determined for five cell types: mesophyll, bundle sheath, phloem companion, epidermal and guard cells. Mesophyll and bundle sheath cells showed the strongest response to paraquat treatment. Interestingly, several ROS-responsive transcription factors displayed cell type-specific translation patterns, while others were translated in all cell types. In part, cell type-specific translation could be explained by the length of the 5-untranslated region (5-UTR) and the presence of upstream open reading frames (uORFs). Our analysis reveals insights into the translational regulation of ROS-responsive genes, which is important to understanding cell-specific responses and functions during oxidative stress. The study illustrates the response of different Arabidopsis thaliana leaf cells and tissues to oxidative stress at the translational level, an aspect of reactive oxygen species (ROS) biology that has been little studied in the past. Our data reveal insights into how translational regulation of ROS-responsive genes is fine-tuned at the cellular level, a phenomenon contributing to the integrated physiological response of leaves to stresses involving changes in ROS levels.}, language = {en} }