@article{SchroederLissoObataetal.2014, author = {Schroeder, Florian and Lisso, Janina and Obata, Toshihiro and Erban, Alexander and Maximova, Eugenia and Giavalisco, Patrick and Kopka, Joachim and Fernie, Alisdair R. and Willmitzer, Lothar and Muessig, Carsten}, title = {Consequences of induced brassinosteroid deficiency in Arabidopsis leaves}, series = {BMC plant biology}, volume = {14}, journal = {BMC plant biology}, publisher = {BioMed Central}, address = {London}, issn = {1471-2229}, doi = {10.1186/s12870-014-0309-0}, pages = {14}, year = {2014}, abstract = {Background: The identification of brassinosteroid (BR) deficient and BR insensitive mutants provided conclusive evidence that BR is a potent growth-promoting phytohormone. Arabidopsis mutants are characterized by a compact rosette structure, decreased plant height and reduced root system, delayed development, and reduced fertility. Cell expansion, cell division, and multiple developmental processes depend on BR. The molecular and physiological basis of BR action is diverse. The BR signalling pathway controls the activity of transcription factors, and numerous BR responsive genes have been identified. The analysis of dwarf mutants, however, may to some extent reveal phenotypic changes that are an effect of the altered morphology and physiology. This restriction holds particularly true for the analysis of established organs such as rosette leaves. Results: In this study, the mode of BR action was analysed in established leaves by means of two approaches. First, an inhibitor of BR biosynthesis (brassinazole) was applied to 21-day-old wild-type plants. Secondly, BR complementation of BR deficient plants, namely CPD (constitutive photomorphogenic dwarf)-antisense and cbb1 (cabbage1) mutant plants was stopped after 21 days. BR action in established leaves is associated with stimulated cell expansion, an increase in leaf index, starch accumulation, enhanced CO2 release by the tricarboxylic acid cycle, and increased biomass production. Cell number and protein content were barely affected. Conclusion: Previous analysis of BR promoted growth focused on genomic effects. However, the link between growth and changes in gene expression patterns barely provided clues to the physiological and metabolic basis of growth. Our study analysed comprehensive metabolic data sets of leaves with altered BR levels. The data suggest that BR promoted growth may depend on the increased provision and use of carbohydrates and energy. BR may stimulate both anabolic and catabolic pathways.}, language = {en} } @article{LissoSchroederMuessig2013, author = {Lisso, Janina and Schr{\"o}der, Florian and M{\"u}ssig, Carsten}, title = {EXO modifies sucrose and trehalose responses and connects the extracellular carbon status to growth}, series = {Frontiers in plant science}, volume = {4}, journal = {Frontiers in plant science}, number = {25}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-462X}, doi = {10.3389/fpls.2013.00219}, pages = {18}, year = {2013}, abstract = {Plants have the capacity to adapt growth to changing environmental conditions. This implies the modulation of metabolism according to the availability of carbon (C). Particular interest in the response to the C availability is based on the increasing atmospheric levels of CO2. Several regulatory pathways that link the C status to growth have emerged. The extracellular EXO protein is essential for cell expansion and promotes shoot and root growth. Homologous proteins were identified in evolutionarily distant green plants. We show here that the EXO protein connects growth with C responses. The exo mutant displayed altered responses to exogenous sucrose supplemented to the growth medium. Impaired growth of the mutant in synthetic medium was associated with the accumulation of starch and anthocyanins, altered expression of sugar-responsive genes, and increased abscisic acid levels. Thus, EXO modulates several responses related to the C availability. Growth retardation on medium supplemented with 2-deoxy-glucose, mannose, and palatinose was similar to the wildtype. Trehalose feeding stimulated root growth and shoot biomass production of exoplants where as it inhibited growth of the wildtype. The phenotypic features of the exo mutant suggest that apoplastic processes coordinate growth and C responses.}, language = {en} } @article{SchroederLissoMuessig2011, author = {Schr{\"o}der, Florian and Lisso, Janina and Muessig, Carsten}, title = {Exordium-Like1 promotes growth during low carbon availability in arabidopsis}, series = {Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants}, volume = {156}, journal = {Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants}, number = {3}, publisher = {American Society of Plant Physiologists}, address = {Rockville}, issn = {0032-0889}, doi = {10.1104/pp.111.177204}, pages = {1620 -- 1630}, year = {2011}, abstract = {Little is known about genes that control growth and development under low carbon (C) availability. The Arabidopsis (Arabidopsis thaliana) EXORDIUM-LIKE1 (EXL1) gene (At1g35140) was identified as a brassinosteroid-regulated gene in a previous study. We show here that the EXL1 protein is required for adaptation to C-and energy-limiting growth conditions. In-depth analysis of EXL1 transcript levels under various environmental conditions indicated that EXL1 expression is controlled by the C and energy status. Sugar starvation, extended night, and anoxia stress induced EXL1 gene expression. The C status also determined EXL1 protein levels. These results suggested that EXL1 is involved in the C-starvation response. Phenotypic changes of an exl1 loss-of-function mutant became evident only under corresponding experimental conditions. The mutant showed diminished biomass production in a short-day/low-light growth regime, impaired survival during extended night, and impaired survival of anoxia stress. Basic metabolic processes and signaling pathways are presumed to be barely impaired in exl1, because the mutant showed wild-type levels of major sugars, and transcript levels of only a few genes such as QUA-QUINE STARCH were altered. Our data suggest that EXL1 is part of a regulatory pathway that controls growth and development when C and energy supply is poor.}, language = {en} } @article{LissoSteinhaeuserAltmannetal.2005, author = {Lisso, Janina and Steinhaeuser, Dirk and Altmann, Thomas and Kopka, Joachim and M{\"u}ssig, Carsten}, title = {Identification of brassinosteroid-related genes by means of transcript co-response analyses}, issn = {0305-1048}, year = {2005}, abstract = {The comprehensive systems-biology database (CSB.DB) was used to reveal brassinosteroid (BR)-related genes from expression profiles based on co-response analyses. Genes exhibiting simultaneous changes in transcript levels are candidates of common transcriptional regulation. Combining numerous different experiments in data matrices allows ruling out outliers and conditional changes of transcript levels. CSB.DB was queried for transcriptional co-responses with the BR-signalling components BRI1 and BAK1: 301 out of 9694 genes represented in the nasc0271 database showed co-responses with both genes. As expected, these genes comprised pathway-involved genes (e.g. 72 BR-induced genes), because the BRI1 and BAK1 proteins are required for BR-responses. But transcript co-response takes the analysis a step further compared with direct approaches because BR-related non BR-responsive genes were identified. Insights into networks and the functional context of genes are provided, because factors determining expression patterns are reflected in correlations. Our findings demonstrate that transcript co-response analysis presents a valuable resource to uncover common regulatory patterns of genes. Different data matrices in CSB.DB allow examination of specific biological questions. All matrices are publicly available through CSB.DB. This work presents one possible roadmap to use the CSB.DB resources}, language = {en} } @article{LissoAltmannMuessig2006, author = {Lisso, Janina and Altmann, Thomas and M{\"u}ssig, Carsten}, title = {Metabolic changes in fruits of the tomato d(x) mutant}, series = {Phytochemistry : an international journal of plant biochemistry}, volume = {67}, journal = {Phytochemistry : an international journal of plant biochemistry}, number = {20}, publisher = {Elsevier}, address = {Oxford}, issn = {0031-9422}, doi = {10.1016/j.phytochem.2006.07.008}, pages = {2232 -- 2238}, year = {2006}, language = {en} } @article{MuessigLissoCollGarciaetal.2006, author = {M{\"u}ssig, Carsten and Lisso, Janina and Coll-Garcia, Danahe and Altmann, Thomas}, title = {Molecular analysis of brassinosteroid action}, doi = {10.1055/s-2005-873043}, year = {2006}, abstract = {Brassinosteroids (BRs) are steroidal plant hormones with important regulatory roles in various physiological processes, including growth, xylem differentiation, disease resistance, and stress tolerance. Several components of the BR signal transduction pathway have been identified. The extracellular domains of receptor kinases such as BRI1 perceive BRs and transduce the signal via intracellular kinase domains. Within the cell further kinases and phosphatases determine the phosphorylation status of transcription factors such as BES1 and BZR1. These factors mediate major BR effects. Studies of BR-regulated genes shed light on the molecular mode of BR action. Genes encoding cell-wall-modifying enzymes, enzymes of the BR biosynthetic pathway, transcription factors, and proteins involved in primary and secondary metabolism are subject to BR-regulation. Gene expression data also point at interactions with other phytohormones and a role of BR in stress responses. This article gives a survey of the BR-signaling pathway. Two BR-responsive genes, OPR3 and EXO, are described in detail}, language = {en} } @article{LissoSchroederFisahnetal.2011, author = {Lisso, Janina and Schr{\"o}der, Florian and Fisahn, Joachim and Muessig, Carsten}, title = {NFX1-LIKE2 (NFXL2) Suppresses Abscisic Acid Accumulation and Stomatal Closure in Arabidopsis thaliana}, series = {PLoS one}, volume = {6}, journal = {PLoS one}, number = {11}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0026982}, pages = {12}, year = {2011}, abstract = {The NFX1-LIKE1 (NFXL1) and NFXL2 genes were identified as regulators of salt stress responses. The NFXL1 protein is a nuclear factor that positively affects adaptation to salt stress. The nfxl1-1 loss-of-function mutant displayed reduced survival rates under salt and high light stress. In contrast, the nfxl2-1 mutant, defective in the NFXL2 gene, and NFXL2-antisense plants exhibited enhanced survival under these conditions. We show here that the loss of NFXL2 function results in abscisic acid (ABA) overaccumulation, reduced stomatal conductance, and enhanced survival under drought stress. The nfxl2-1 mutant displayed reduced stomatal aperture under all conditions tested. Fusicoccin treatment, exposition to increasing light intensities, and supply of decreasing CO2 concentrations demonstrated full opening capacity of nfxl2-1 stomata. Reduced stomatal opening presumably is a consequence of elevated ABA levels. Furthermore, seedling growth, root growth, and stomatal closure were hypersensitive to exogenous ABA. The enhanced ABA responses may contribute to the improved drought stress resistance of the mutant. Three NFXL2 splice variants were cloned and named NFXL2-78, NFXL2-97, and NFXL2-100 according to the molecular weight of the putative proteins. Translational fusions to the green fluorescent protein suggest nuclear localisation of the NFXL2 proteins. Stable expression of the NFXL2-78 splice variant in nfxl2-1 plants largely complemented the mutant phenotype. Our data show that NFXL2 controls ABA levels and suppresses ABA responses. NFXL2 may prevent unnecessary and costly stress adaptation under favourable conditions.}, language = {en} } @article{LissoAltmannMuessig2006, author = {Lisso, Janina and Altmann, Thomas and M{\"u}ssig, Carsten}, title = {The AtNFXL1 gene encodes a NF-X1 type zinc finger protein required for growth under salt stress}, series = {FEBS letters : the journal for rapid publication of short reports in molecular biosciences}, volume = {580}, journal = {FEBS letters : the journal for rapid publication of short reports in molecular biosciences}, number = {22}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0014-5793}, doi = {10.1016/j.febslet.2006.07.079}, pages = {4851 -- 4856}, year = {2006}, abstract = {The human NF-X1 protein and homologous proteins in eukaryotes represent a class of transcription factors which are characterised. by NF-X1 type zinc finger motifs. The Arabidopsis genome encodes two NF-X1 homologs, which we termed AtNFXL1 and AtNFXL2. Growth and survival was impaired in atnfxl1 knock-out mutants and AtNFXL1-antisense plants under salt stress in comparison to wild-type plants. In contrast, 35S: :AtNFXL1 plants showed higher survival rates. The AtNFXL2 protein potentially plays an antagonistic role. The Arabidopsis NF-X1 type zinc finger proteins likely are part of regulatory mechanisms, which protect major processes such as photosynthesis.}, language = {en} }