TY - JOUR ID - 1359 TI - Jasmonates: biosynthesis, perception, signal transduction and action in plant stress response, growth and development. An update to the 2007 review in Annals of Botany JO - Ann. Bot. PY - 2013 SP - 1021-1058 AU - Wasternack, C. AU - Hause, B. AU - VL - 111 UR - DO - 10.1093/aob/mct067 AB - BackgroundJasmonates are important regulators in plant responses to biotic and abiotic stresses as well as in development. Synthesized from lipid-constituents, the initially formed jasmonic acid is converted to different metabolites including the conjugate with isoleucine. Important new components of jasmonate signalling including its receptor were identified, providing deeper insight into the role of jasmonate signalling pathways in stress responses and development.ScopeThe present review is an update of the review on jasmonates published in this journal in 2007. New data of the last five years are described with emphasis on metabolites of jasmonates, on jasmonate perception and signalling, on cross-talk to other plant hormones and on jasmonate signalling in response to herbivores and pathogens, in symbiotic interactions, in flower development, in root growth and in light perception.ConclusionsThe last few years have seen breakthroughs in the identification of JASMONATE ZIM DOMAIN (JAZ) proteins and their interactors such as transcription factors and co-repressors, and the crystallization of the jasmonate receptor as well as of the enzyme conjugating jasmonate to amino acids. Now, the complex nature of networks of jasmonate signalling in stress responses and development including hormone cross-talk can be addressed. A2 - C1 - Cell and Metabolic Biology; Molecular Signal Processing ER - TY - JOUR ID - 1358 TI - Jasmonates in flower and seed development JO - Biochimie PY - 2013 SP - 79-85 AU - Wasternack, C. AU - Forner, S. AU - Strnad, M. AU - Hause, B. AU - VL - 95 UR - DO - 10.1016/j.biochi.2012.06.005 AB - Jasmonates are ubiquitously occurring lipid-derived signaling compounds active in plant development and plant responses to biotic and abiotic stresses. Upon environmental stimuli jasmonates are formed and accumulate transiently. During flower and seed development, jasmonic acid (JA) and a remarkable number of different metabolites accumulate organ- and tissue specifically. The accumulation is accompanied with expression of jasmonate-inducible genes. Among these genes there are defense genes and developmentally regulated genes. The profile of jasmonate compounds in flowers and seeds covers active signaling molecules such as JA, its precursor 12-oxophytodienoic acid (OPDA) and amino acid conjugates such as JA-Ile, but also inactive signaling molecules occur such as 12-hydroxy-JA and its sulfated derivative. These latter compounds can occur at several orders of magnitude higher level than JA. Metabolic conversion of JA and JA-Ile to hydroxylated compounds seems to inactivate JA signaling, but also specific functions of jasmonates in flower and seed development were detected. In tomato OPDA is involved in embryo development. Occurrence of jasmonates, expression of JA-inducible genes and JA-dependent processes in flower and seed development will be discussed. A2 - C1 - Cell and Metabolic Biology; Molecular Signal Processing ER - TY - JOUR ID - 1337 TI - Optimized Probe Masking for Comparative Transcriptomics of Closely Related Species JO - PLOS ONE PY - 2013 SP - e78497 AU - Poeschl, Y. AU - Delker, C. AU - Trenner, J. AU - Ullrich, K. K. AU - Quint, M. AU - Grosse, I. AU - VL - 8 UR - DO - 10.1371/journal.pone.0078497 AB - Microarrays are commonly applied to study the transcriptome of specific species. However, many available microarrays are restricted to model organisms, and the design of custom microarrays for other species is often not feasible. Hence, transcriptomics approaches of non-model organisms as well as comparative transcriptomics studies among two or more species often make use of cost-intensive RNAseq studies or, alternatively, by hybridizing transcripts of a query species to a microarray of a closely related species. When analyzing these cross-species microarray expression data, differences in the transcriptome of the query species can cause problems, such as the following: (i) lower hybridization accuracy of probes due to mismatches or deletions, (ii) probes binding multiple transcripts of different genes, and (iii) probes binding transcripts of non-orthologous genes. So far, methods for (i) exist, but these neglect (ii) and (iii). Here, we propose an approach for comparative transcriptomics addressing problems (i) to (iii), which retains only transcript-specific probes binding transcripts of orthologous genes. We apply this approach to an Arabidopsis lyrata expression data set measured on a microarray designed for Arabidopsis thaliana, and compare it to two alternative approaches, a sequence-based approach and a genomic DNA hybridization-based approach. We investigate the number of retained probe sets, and we validate the resulting expression responses by qRT-PCR. We find that the proposed approach combines the benefit of sequence-based stringency and accuracy while allowing the expression analysis of much more genes than the alternative sequence-based approach. As an added benefit, the proposed approach requires probes to detect transcripts of orthologous genes only, which provides a superior base for biological interpretation of the measured expression responses. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1333 TI - Plant F-Box Protein Evolution Is Determined by Lineage-Specific Timing of Major Gene Family Expansion Waves JO - PLOS ONE PY - 2013 SP - e68672 AU - Navarro-Quezada, A. AU - Schumann, N. AU - Quint, M. AU - VL - 8 UR - DO - 10.1371/journal.pone.0068672 AB - F-box proteins (FBPs) represent one of the largest and fastest evolving gene/protein families in the plant kingdom. The FBP superfamily can be divided in several subfamilies characterized by different C-terminal protein-protein interaction domains that recruit targets for proteasomal degradation. Hence, a clear picture of their phylogeny and molecular evolution is of special interest for the general understanding of evolutionary histories of multi-domain and/or large protein families in plants. In an effort to further understand the molecular evolution of F-box family proteins, we asked whether the largest subfamily in Arabidopsis thaliana, which carries a C-terminal F-box associated domain (FBA proteins) shares evolutionary patterns and signatures of selection with other FBPs. To address this question, we applied phylogenetic and molecular evolution analyses in combination with the evaluation of transcriptional profiles. Based on the 2219 FBA proteins we de novo identified in 34 completely sequenced plant genomes, we compared their evolutionary patterns to a previously analyzed large subfamily carrying C-terminal kelch repeats. We found that these two large FBP subfamilies generally tend to evolve by massive waves of duplication, followed by sequence conservation of the F-box domain and sequence diversification of the target recruiting domain. We conclude that the earlier in evolutionary time a major wave of expansion occurred, the more pronounced these selection signatures are. As a consequence, when performing cross species comparisons among FBP subfamilies, significant differences will be observed in the selective signatures of protein-protein interaction domains. Depending on the species, the investigated subfamilies comprise up to 45% of the complete superfamily, indicating that other subfamilies possibly follow similar modes of evolution. A2 - C1 - Molecular Signal Processing; Biochemistry of Plant Interactions ER - TY - JOUR ID - 1326 TI - Kinetic analysis of Arabidopsis glucosyltransferase UGT74B1 illustrates a general mechanism by which enzymes can escape product inhibition JO - Biochem. J. PY - 2013 SP - 37-46 AU - Kopycki, J. AU - Wieduwild, E. AU - Kohlschmidt, J. AU - Brandt, W. AU - Stepanova, A. AU - Alonso, J. AU - Pedras, M. S. AU - Abel, S. AU - Grubb, C. D. AU - VL - 450 UR - DO - 10.1042/BJ20121403 AB - Plant genomes encode numerous small molecule glycosyltransferases which modulate the solubility, activity, immunogenicity and/or reactivity of hormones, xenobiotics and natural products. The products of these enzymes can accumulate to very high concentrations, yet somehow avoid inhibiting their own biosynthesis. Glucosyltransferase UGT74B1 (UDP-glycosyltransferase 74B1) catalyses the penultimate step in the core biosynthetic pathway of glucosinolates, a group of natural products with important functions in plant defence against pests and pathogens. We found that mutation of the highly conserved Ser284 to leucine [wei9-1 (weak ethylene insensitive)] caused only very mild morphological and metabolic phenotypes, in dramatic contrast with knockout mutants, indicating that steady state glucosinolate levels are actively regulated even in unchallenged plants. Analysis of the effects of the mutation via a structural modelling approach indicated that the affected serine interacts directly with UDP-glucose, but also predicted alterations in acceptor substrate affinity and the kcat value, sparking an interest in the kinetic behaviour of the wild-type enzyme. Initial velocity and inhibition studies revealed that UGT74B1 is not inhibited by its glycoside product. Together with the effects of the missense mutation, these findings are most consistent with a partial rapid equilibrium ordered mechanism. This model explains the lack of product inhibition observed both in vitro and in vivo, illustrating a general mechanism whereby enzymes can continue to function even at very high product/precursor ratios. A2 - C1 - Bioorganic Chemistry; Molecular Signal Processing ER - TY - JOUR ID - 1318 TI - The eta7/csn3-3 Auxin Response Mutant of Arabidopsis Defines a Novel Function for the CSN3 Subunit of the COP9 Signalosome JO - PLOS ONE PY - 2013 SP - e66578 AU - Huang, H. AU - Quint, M. AU - Gray, W. M. AU - VL - 8 UR - DO - 10.1371/journal.pone.0066578 AB - The COP9 signalosome (CSN) is an eight subunit protein complex conserved in all higher eukaryotes. In Arabidopsis thaliana, the CSN regulates auxin response by removing the ubiquitin-like protein NEDD8/RUB1 from the CUL1 subunit of the SCFTIR1/AFB ubiquitin-ligase (deneddylation). Previously described null mutations in any CSN subunit result in the pleiotropic cop/det/fus phenotype and cause seedling lethality, hampering the study of CSN functions in plant development. In a genetic screen to identify enhancers of the auxin response defects conferred by the tir1-1 mutation, we identified a viable csn mutant of subunit 3 (CSN3), designated eta7/csn3-3. In addition to enhancing tir1-1 mutant phenotypes, the csn3-3 mutation alone confers several phenotypes indicative of impaired auxin signaling including auxin resistant root growth and diminished auxin responsive gene expression. Unexpectedly however, csn3-3 plants are not defective in either the CSN-mediated deneddylation of CUL1 or in SCFTIR1-mediated degradation of Aux/IAA proteins. These findings suggest that csn3-3 is an atypical csn mutant that defines a novel CSN or CSN3-specific function. Consistent with this possibility, we observe dramatic differences in double mutant interactions between csn3-3 and other auxin signaling mutants compared to another weak csn mutant, csn1-10. Lastly, unlike other csn mutants, assembly of the CSN holocomplex is unaffected in csn3-3 plants. However, we detected a small CSN3-containing protein complex that is altered in csn3-3 plants. We hypothesize that in addition to its role in the CSN as a cullin deneddylase, CSN3 functions in a distinct protein complex that is required for proper auxin signaling. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1301 TI - Morphological and biochemical behavior of fenugreek (Trigonella foenum-graecum) under copper stress JO - Ecotoxicol. Environ. Saf. PY - 2013 SP - 46-53 AU - Elleuch, A. AU - Chaâbene, Z. AU - Grubb, D. C. AU - Drira, N. AU - Mejdoub, H. AU - Khemakhem, B. AU - VL - 98 UR - DO - 10.1016/j.ecoenv.2013.09.028 AB - The effects of copper on germination and growth of fenugreek (Trigonella foenum-graecum) was investigated separately using different concentrations of CuSO4. The germination percentage and radical length had different responses to cupric ions: the root growth increased with increasing copper concentration up to 1 mM and Cu2+ was inhibited thereafter. In contrast, the germination percentage was largely unaffected by concentrations of copper below 10 mM.The reduction in root growth may have been due to inhibition of hydrolytic enzymes such as amylase. Indeed, the average total amylolytic activity decreased from the first day of treatment with [Cu2+] greater than 1 mM. Furthermore, copper affected various plant growth parameters. Copper accumulation was markedly higher in roots as compared to shoots. While both showed a gradual decrease in growth, this was more pronounced in roots than in leaves and in stems. Excess copper induced an increase in the rate of hydrogen peroxide (H2O2) production and lipid peroxidation in all plant parts, indicating oxidative stress. This redox stress affected leaf chlorophyll and carotenoid content which decreased in response to augmented Cu levels. Additionally, the activities of proteins involved in reactive oxygen species (ROS) detoxification were affected. Cu stress elevated the ascorbate peroxidase (APX) activity more than two times at 10 mM CuSO4. In contrast, superoxide dismutase (SOD) and catalase (CAT) levels showed only minor variations, only at 1 mM Cu2+. Likewise, total phenol and flavonoid contents were strongly induced by low concentrations of copper, consistent with the role of these potent antioxidants in scavenging ROS such as H2O2, but returned to control levels or below at high [Cu2+]. Taken together, these results indicate a fundamental shift in the plant response to copper toxicity at low versus high concentrations. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1298 TI - Transcriptional Dynamics of Two Seed Compartments with Opposing Roles in Arabidopsis Seed Germination JO - Plant Physiol. PY - 2013 SP - 205-215 AU - Dekkers, B. J. AU - Pearce, S. AU - van Bolderen-Veldkamp, R. AU - Marshall, A. AU - Widera, P. AU - Gilbert, J. AU - Drost, H.-G. AU - Bassel, G. W. AU - Müller, K. AU - King, J. R. AU - Wood, A. T. AU - Grosse, I. AU - Quint, M. AU - Krasnogor, N. AU - Leubner-Metzger, G. AU - Holdsworth, M. J. AU - Bentsink, L. AU - VL - 163 UR - DO - 10.1104/pp.113.223511 AB - Seed germination is a critical stage in the plant life cycle and the first step toward successful plant establishment. Therefore, understanding germination is of important ecological and agronomical relevance. Previous research revealed that different seed compartments (testa, endosperm, and embryo) control germination, but little is known about the underlying spatial and temporal transcriptome changes that lead to seed germination. We analyzed genome-wide expression in germinating Arabidopsis (Arabidopsis thaliana) seeds with both temporal and spatial detail and provide Web-accessible visualizations of the data reported (vseed.nottingham.ac.uk). We show the potential of this high-resolution data set for the construction of meaningful coexpression networks, which provide insight into the genetic control of germination. The data set reveals two transcriptional phases during germination that are separated by testa rupture. The first phase is marked by large transcriptome changes as the seed switches from a dry, quiescent state to a hydrated and active state. At the end of this first transcriptional phase, the number of differentially expressed genes between consecutive time points drops. This increases again at testa rupture, the start of the second transcriptional phase. Transcriptome data indicate a role for mechano-induced signaling at this stage and subsequently highlight the fates of the endosperm and radicle: senescence and growth, respectively. Finally, using a phylotranscriptomic approach, we show that expression levels of evolutionarily young genes drop during the first transcriptional phase and increase during the second phase. Evolutionarily old genes show an opposite pattern, suggesting a more conserved transcriptome prior to the completion of germination. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1295 TI - Arabidopsis Calmodulin-binding Protein IQ67-Domain 1 Localizes to Microtubules and Interacts with Kinesin Light Chain-related Protein-1 JO - J. Biol. Chem. PY - 2013 SP - 1871-1882 AU - Bürstenbinder, K. AU - Savchenko, T. AU - Müller, J. AU - Adamson, A. W. AU - Stamm, G. AU - Kwong, R. AU - Zipp, B. J. AU - Dinesh, D. C. AU - Abel, S. AU - VL - 288 UR - DO - 10.1074/jbc.M112.396200 AB - Calcium (Ca2+) is a key second messenger in eukaryotes and regulates diverse cellular processes, most notably via calmodulin (CaM). In Arabidopsis thaliana, IQD1 (IQ67 domain 1) is the founding member of the IQD family of putative CaM targets. The 33 predicted IQD proteins share a conserved domain of 67 amino acids that is characterized by a unique arrangement of multiple CaM recruitment motifs, including so-called IQ motifs. Whereas IQD1 has been implicated in the regulation of defense metabolism, the biochemical functions of IQD proteins remain to be elucidated. In this study we show that IQD1 binds to multiple Arabidopsis CaM and CaM-like (CML) proteins in vitro and in yeast two-hybrid interaction assays. CaM overlay assays revealed moderate affinity of IQD1 to CaM2 (Kd ∼ 0.6 μm). Deletion mapping of IQD1 demonstrated the importance of the IQ67 domain for CaM2 binding in vitro, which is corroborated by interaction of the shortest IQD member, IQD20, with Arabidopsis CaM/CMLs in yeast. A genetic screen of a cDNA library identified Arabidopsis kinesin light chain-related protein-1 (KLCR1) as an IQD1 interactor. The subcellular localization of GFP-tagged IQD1 proteins to microtubules and the cell nucleus in transiently and stably transformed plant tissues (tobacco leaves and Arabidopsis seedlings) suggests direct interaction of IQD1 and KLCR1 in planta that is supported by GFP∼IQD1-dependent recruitment of RFP∼KLCR1 and RFP∼CaM2 to microtubules. Collectively, the prospect arises that IQD1 and related proteins provide Ca2+/CaM-regulated scaffolds for facilitating cellular transport of specific cargo along microtubular tracks via kinesin motor proteins. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1285 TI - Role of NINJA in root jasmonate signaling JO - Proc. Natl. Acad. Sci. U.S.A. PY - 2013 SP - 15473-15478 AU - Acosta, I. F. AU - Gasperini, D. AU - Chételat, A. AU - Stolz, S. AU - Santuari, L. AU - Farmer, E. E. AU - VL - 110 UR - DO - 10.1073/pnas.1307910110 AB - Wound responses in plants have to be coordinated between organs so that locally reduced growth in a wounded tissue is balanced by appropriate growth elsewhere in the body. We used a JASMONATE ZIM DOMAIN 10 (JAZ10) reporter to screen for mutants affected in the organ-specific activation of jasmonate (JA) signaling in Arabidopsis thaliana seedlings. Wounding one cotyledon activated the reporter in both aerial and root tissues, and this was either disrupted or restricted to certain organs in mutant alleles of core components of the JA pathway including COI1, OPR3, and JAR1. In contrast, three other mutants showed constitutive activation of the reporter in the roots and hypocotyls of unwounded seedlings. All three lines harbored mutations in Novel Interactor of JAZ (NINJA), which encodes part of a repressor complex that negatively regulates JA signaling. These ninja mutants displayed shorter roots mimicking JA-mediated growth inhibition, and this was due to reduced cell elongation. Remarkably, this phenotype and the constitutive JAZ10 expression were still observed in backgrounds lacking the ability to synthesize JA or the key transcriptional activator MYC2. Therefore, JA-like responses can be recapitulated in specific tissues without changing a plant’s ability to make or perceive JA, and MYC2 either has no role or is not the only derepressed transcription factor in ninja mutants. Our results show that the role of NINJA in the root is to repress JA signaling and allow normal cell elongation. Furthermore, the regulation of the JA pathway differs between roots and aerial tissues at all levels, from JA biosynthesis to transcriptional activation. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1284 TI - The emerging function of IQD proteins as scaffolds in cellular signaling and trafficking JO - Plant Signal Behav. PY - 2013 SP - e24369 AU - Abel, S. AU - Bürstenbinder, K. AU - Müller, J. AU - VL - 8 UR - DO - 10.4161/psb.24369 AB - Calcium (Ca2+) signaling modules are essential for adjusting plant growth and performance to environmental constraints. Differential interactions between sensors of Ca2+ dynamics and their molecular targets are at the center of the transduction process. Calmodulin (CaM) and CaM-like (CML) proteins are principal Ca2+-sensors in plants that govern the activities of numerous downstream proteins with regulatory properties. The families of IQ67-Domain (IQD) proteins are a large class of plant-specific CaM/CML-targets (e.g., 33 members in A. thaliana) which share a unique domain of multiple varied CaM retention motifs in tandem orientation. Genetic studies in Arabidopsis and tomato revealed first roles for IQD proteins related to basal defense response and plant development. Molecular, biochemical and histochemical analysis of Arabidopsis IQD1 demonstrated association with microtubules as well as targeting to the cell nucleus and nucleolus. In vivo binding to CaM and kinesin light chain-related protein-1 (KLCR1) suggests a Ca2+-regulated scaffolding function of IQD1 in kinesin motor-dependent transport of multiprotein complexes. Furthermore, because IQD1 interacts in vitro with single-stranded nucleic acids, the prospect arises that IQD1 and other IQD family members facilitate cellular RNA localization as one mechanism to control and fine-tune gene expression and protein sorting. A2 - C1 - Molecular Signal Processing ER - TY - CHAP ID - 85 TI - Benno Parthier und die Jasmonatforschung in Halle T2 - Festkolloquium der Leopoldina anlässlich des 80. Geburtstages von Herrn Altpräsidenten Benno Parthier PB - Nova Acta Leopoldina PY - 2013 SP - 29-38 AU - Wasternack, C. AU - Hause, B. AU - VL - Supplementum Nr. 28 UR - https://www.leopoldina.org/publikationen/detailansicht/publication/festkolloquium-der-leopoldina-anlaesslich-des-80-geburtstages-von-herrn-altpraesidenten-benno-parthie/ AB - A2 - Hacker, J., ed. C1 - Cell and Metabolic Biology; Molecular Signal Processing ER - TY - JOUR ID - 2415 TI - Jasmonate-signalled plant gene expression JO - Trends Plant Sci. PY - 1997 SP - 302-307 AU - Wasternack, C. AU - Parthier, B. AU - VL - 2 UR - DO - 10.1016/S1360-1385(97)89952-9 AB - Jasmonic acid is distributed throughout higher plants, synthesized from linolenic acid via the octadecanoic pathway. An important and probably essential role seems to be its operation as a ‘master switch’, responsible for the activation of signal transduction pathways in response to predation and pathogen attack. Proteins encoded by jasmonate-induced genes include enzymes of alkaloid and phytoalexin synthesis, storage proteins, cell wall constituents and stress protectants. The wound-induced formation of proteinase inhibitors is a well-studied example, in which jasmonic acid combines with abscisic acid and ethylene to protect the plant from predation. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2414 TI - Molecular modelling, synthesis and biological activity of methyl 3-methyljasmonate and related derivatives JO - Tetrahedron PY - 1997 SP - 8181-8194 AU - Ward, J. L. AU - Gaskin, P. AU - Beale, M. H. AU - Sessions, R. AU - Koda, Y. AU - Wasternack, C. AU - VL - 53 UR - DO - 10.1016/S0040-4020(97)00485-7 AB - Methyl 3-methyljasmonate was synthesised from methyl jasmonate via methyl 3,7-dehydrojasmonate. Molecular modelling predicted an increase in the proportion of cis-orientated side-chains for equilibrated 3-methyl-substituted jasmonate. The synthetic 3-methyljasmonate was shown by gc-ms analysis to equilibrate to a 2:1 ratio of isomers, which appeared from the NMR spectra to comprise mainly the cis-isomer. Surprisingly, both 3,7-dehydro- and 3-methyl-derivatives were inactive in four well established jasmonate bioassays. Methyl-2-methyljasmonate was synthesised and also found to be inactive. Methyl 4,5-dehydrojasmonate was prepared, via the 5-diazo derivative. Both of these compounds have low activity. Our results are discussed with reference to previous knowledge of jasmonate structure-activity relationships and indicate that there are stringent steric demands in jasmonate-receptor interactions. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2402 TI - Chiral separation of amide conjugates of jasmonic acid by liquid chromatography JO - Chromatographia PY - 1997 SP - 104-108 AU - Kramell, R. AU - Schneider, G. AU - Miersch, O. AU - VL - 45 UR - DO - 10.1007/BF02505545 AB - Synthetic amide conjugates of (−)-jasmonic acid and its (+)-enantiomer were resolved by means of chiral liquid chromatography. The diastereomeric pairs prepared by chemical reaction of (±)-jasmonic acid with a series of (S)- or (R)-amino acids and with some (S)-amino acid alcohols were completely separated on Chiralpak AS using a mixture of n-hexane/2-propanal as mobile phase. The retention data indicate that the (−)-jasmonic acid conjugates eluted faster than those of the (+)-enantiomer, independent on the configuration of the bound amino acid. Likewise, enantiomeric derivatives of (±)-jasmonic acid and non-chiral amino acids were completely separated on the chiral stationary phase and showed the same elution sequence. The resolution factors,Rs, were found to range between 1.13 and 6.64. The separated compounds were chiropatically analyzed by measurement of the circular dichroism. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2401 TI - Amino acid conjugates of jasmonic acid induce jasmonate-responsive gene expression in barley (Hordeum vulgare L.) leaves JO - FEBS Lett. PY - 1997 SP - 197-202 AU - Kramell, R. AU - Miersch, O. AU - Hause, B. AU - Ortel, B. AU - Parthier, B. AU - Wasternack, C. AU - VL - 414 UR - DO - 10.1016/S0014-5793(97)01005-3 AB - Leaves of barley (Hordeum vulgare L. cv. Salome ) treated with jasmonic acid (JA), its methyl ester (JM), or its amino acid conjugates exhibit up‐regulation of specific genes and down‐regulation of house‐keeping genes. This transcriptional regulation exhibits several specificities. (i) The (−)‐enantiomers are more active, and conjugates are mainly active if they carry an l ‐amino acid moiety. (ii) The various JA‐responsive genes respond differentially to enantiomeric and chiralic forms. (iii) Both JA and its amino acid conjugates exhibiting no or negligible interconversion induce/repress genes. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 2397 TI - Partial purification and characterization of a jasmonic acid conjugate cleaving amidohydrolase from the fungus Botryodiplodia theobromae JO - FEBS Lett. PY - 1997 SP - 105-110 AU - Hertel, S. C. AU - Knöfel, H.-D. AU - Kramell, R. AU - Miersch, O. AU - VL - 407 UR - DO - 10.1016/S0014-5793(97)00307-4 AB - A protein preparation from the mycelium of the tropical pathogenic fungus Botryodiplodia theobromae revealed a novel peptidase activity. This enzyme was capable of cleaving conjugates of jasmonic acid with α-amino acids. The protein was enriched 108-fold by gel filtration, ion exchange and hydrophobic interaction chromatography. The enzyme was found to be a glycoprotein with a molecular mass of about 107 kDa. The amidohydrolase seems to be very specific with regard to (−)-jasmonic acid and α-amino acids with (S)-configuration. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2396 TI - Nuclear Location of a Diadenosine 5′,5′”-P1,P4Tetraphosphate (Ap4A) Hydrolase in Tomato Cells Grown in Suspension Cultures JO - Bot. Acta PY - 1997 SP - 452-457 AU - Hause, B. AU - Feussner, K. AU - Wasternack, C. AU - VL - 110 UR - DO - 10.1111/j.1438-8677.1997.tb00662.x AB - Diadenosine 5′,5′”‐P1,P4‐tetraphosphate (Ap4A) cleaving enzymes are assumed to regulate intracellular levels of Ap4A, a compound known to affect cell proliferation and stress responses. From plants an Ap4A hydrolase was recently purified using tomato cells grown in suspension. It was partially sequenced and a peptide antibody was prepared (Feussner et al., 1996). Using this polyclonal monospecific antibody, an abundant nuclear location of Ap4A hydrolase in 4‐day‐old cells of atomato cell suspension culture is demonstrated here by means of immunocytochemical techniques using FITC (fluorescein‐5‐isothiocyanate) labeled secondary antibodies. The microscopic analysis of the occurrence of Ap4A hydrolase performed for different stages of the cell cycle visualized by parallel DAPI (4,6‐diamidino‐2‐phenylindole) staining revealed that the protein accumulates within nuclei of cells in the interphase, but is absent in the nucleus as well as cytoplasm during all stages of mitosis. This first intracellular localization of an Ap4A degrading enzyme within the nucleus and its pattern of appearance during the cell cycle is discussed in relation to the suggested role of Ap4A in triggering DNA synthesis and cell proliferation. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 2395 TI - In barley leaf cells, jasmonates do not act as a signal during compatible or incompatible interactions with the powdery mildew fungus (Erysiphe graminis f. sp. hordei) JO - J. Plant Physiol. PY - 1997 SP - 127-132 AU - Hause, B. AU - Kogel, K.-H. AU - Parthier, B. AU - Wasternack, C. AU - VL - 150 UR - DO - 10.1016/S0176-1617(97)80191-5 AB - We have studied a possible function of jasmonates as mediators in the host-pathogen interaction of barley (Hordeum vulgare L.) with the powdery mildew fungus Egh (Erysiphe graminis f. sp. hordei). Previous findings from whole-leaf extracts demonstrated that (i) extracts from infected barley leaves did not contain enhanced levels of jasmonates, (ii) transcripts of jasmonate-inducible genes were not expressed upon infection, and (iii) exogenous application of jasmonates did not induce resistance to Egh (Kogel et al., 1995). Nevertheless, the question arises whether or not jasmonates are involved in the interaction of barley with the powdery mildew fungus at the local site of infection. Using an immunocytological approach the analysis of leaf cross-sections from a susceptible barley cultivar and its near-isogenic mlo5-resistant line revealed no accumulation of JIP-23, the most abundant jasmonate inducible protein, neither in epidermal cells attacked by the pathogen nor in adjacent mesophyll cells. As a positive control, cross-sections from methyl jasmonate-treated leaf segments showed a strong signal for JIP-23 accumulation. Because the presence of the jasmonate-inducible protein is highly indicative for an already low threshold level of endogenous jasmonate (Lehmann et al., 1995), the lack of JIP-23 accumulation at the sites of attempted fungal infection clearly demonstrates the absence of enhanced levels of jasmonates. This excludes even a local rise of jasmonate confined to those single cells penetrated (Mlo genotype) or attacked (mlo5 genotype) by the fungus. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 2394 TI - Overexpression of the jasmonate-inducible 23 kDa protein (JIP 23) from barley in transgenic tobacco leads to the repression of leaf proteins JO - FEBS Lett. PY - 1997 SP - 58-62 AU - Görschen, E. AU - Dunaeva, M. AU - Reeh, I. AU - Wasternack, C. AU - VL - 419 UR - DO - 10.1016/S0014-5793(97)01433-6 AB - We investigated transgenic tobacco lines which express different amounts of the barley JIP 23. In these plants the amount of several proteins decreased proportionally to increasing amounts of JIP 23 whereas the transcript levels were constant as determined for the small and the large subunit of RuBPCase. However, the translation initiation of the rbcS transcript was found to be less efficient than in the wild type. In contrast, the jip 23 transcript was efficiently initiated, indicating that no unspecific impairment of initiation occurred. The data suggest that the barley JIP 23 leads to discrimination among certain tobacco transcripts during translation initiation. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2393 TI - Expression of the ribosome-inactivating protein JIP60 from barley in transgenic tobacco leads to an abnormal phenotype and alterations on the level of translation JO - Planta PY - 1997 SP - 470-478 AU - Görschen, E. AU - Dunaeva, M. AU - Hause, B. AU - Reeh, I. AU - Wasternack, C. AU - Parthier, B. AU - VL - 202 UR - DO - 10.1007/s004250050151 AB - In this paper we report the in-planta activity of the ribosome-inactivating protein JIP60, a 60-kDa jasmonate-induced protein from barley (Hordeum vulgare L.), in transgenic tobacco (Nicotiana tabacum L.) plants. All plants expressing the complete JIP60 cDNA under the control of the cauliflower mosaic virus (CaMV) 35S promoter exhibited conspicuous and similar phenotypic alterations, such as slower growth, shorter internodes, lanceolate leaves, reduced root development, and premature senescence of leaves. Microscopic inspection of developing leaves showed a loss of residual meristems and higher degree of vacuolation of mesophyll cells as compared to the wild type. When probed with an antiserum which was immunoreactive against both the N- and the C-terminal half of JIP60, a polypeptide with a molecular mass of about 30 kDa, most probably a processed JIP60 product, could be detected. Phenotypic alterations could be correlated with the differences in the detectable amount of the JIP60 mRNA and processed JIP60 protein. The protein biosynthesis of the transformants was characterized by an increased polysome/monosome ratio but a decreased in-vivo translation activity. These findings suggest that JIP60 perturbs the translation machinery in planta. An immunohistological analysis using the JIP60 antiserum indicated that the immunoreactive polypeptide(s) are located mainly in the nucleus of transgenic tobacco leaf cells and to a minor extent in the cytoplasm. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 2389 TI - Structural Elucidation of Oxygenated Storage Lipids in Cucumber Cotyledons JO - J. Biol. Chem. PY - 1997 SP - 21635-21641 AU - Feussner, I. AU - Balkenhohl, T. J. AU - Porzel, A. AU - Kühn, H. AU - Wasternack, C. AU - VL - 272 UR - DO - 10.1074/jbc.272.34.21635 AB - At early stages of germination, a special lipoxygenase is expressed in cotyledons of cucumber and several other plants. This enzyme is localized at the lipid storage organelles and oxygenates their storage triacylglycerols. We have isolated this lipid body lipoxygenase from cucumber seedlings and found that it is capable of oxygenating in vitro di- and trilinolein to the corresponding mono-, di-, and trihydroperoxy derivatives. To investigate the in vivo activity of this enzyme during germination, lipid bodies were isolated from cucumber seedlings at different stages of germination, and the triacylglycerols were analyzed for oxygenated derivatives by a combination of high pressure liquid chromatography, gas chromatography/mass spectrometry, and nuclear magnetic resonance spectroscopy. We identified as major oxygenation products triacylglycerols that contained one, two, or three 13S-hydroperoxy-9(Z),11(E)-octadecadienoic acid residues. During germination, the amount of oxygenated lipids increased strongly, reaching a maximum after 72 h and declining afterward. The highly specific pattern of hydroperoxy lipids formed suggested the involvement of the lipid body lipoxygenase in their biosynthesis.These data suggest that this lipoxygenase may play an important role during the germination process of cucumber and other plants and support our previous hypothesis that the specific oxygenation of the storage lipids may initiate their mobilization as a carbon and energy source for the growing seedling. A2 - C1 - Molecular Signal Processing; Bioorganic Chemistry ER - TY - JOUR ID - 2388 TI - Quantitative Analyse von Lipoxygenase-Metaboliten in Lipiden durch NMR-Spektroskopie JO - BIOspektrum PY - 1997 SP - 54-58 AU - Feussner, I. AU - Porzel, A. AU - Wasternack, C. AU - Kühn, H. AU - VL - 3 UR - AB - A2 - C1 - Molecular Signal Processing; Bioorganic Chemistry ER - TY - JOUR ID - 2387 TI - Isolation of a cDNA coding for an ubiquitin-conjugating enzyme UBC1 of tomato - the first stress-induced UBC of higher plants JO - FEBS Lett. PY - 1997 SP - 211-215 AU - Feussner, K. AU - Feussner, I. AU - Leopold, I. AU - Wasternack, C. AU - VL - 409 UR - DO - 10.1016/S0014-5793(97)00509-7 AB - A clone of an ubiquitin‐conjugating enzyme (UBC) was isolated from a λ‐ZAP‐cDNA library, generated from mRNA of tomato (Lycopersicon esculentum) cells grown in suspension for 3 days. The open reading frame called Le UBC1, encodes for a polypeptide with a predicted molecular mass of 21.37 kDa, which was confirmed by bacterial overexpression and SDS‐PAGE. Database searches with Le UBC1 showed highest sequence similarities to UBC1 of bovine and yeast. By Southern blot analysis Le UBC1 was identified as a member of a small E2 subfamily of tomato, presumably consisting of at least two members. As revealed by Northern blot analysis Le UBC1 is constitutively expressed in an exponentially growing tomato cell culture. In response to heat shock an increase in Le UBC1‐mRNA was detectable. A strong accumulation of the Le UBC1‐transcript was observed by exposure to heavy metal stress which was performed by treatment with cadmium chloride (CdCl2). The cellular uptake of cadmium was controlled via ICP‐MS measurements. The data suggest that like in yeast, in plants a certain subfamily of UBC is specifically involved in the proteolytic degradation of abnormal proteins as result of stress. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2386 TI - Induction of a new Lipoxygenase Form in Cucumber Leaves by Salicylic Acid or 2,6-Dichloroisonicotinic Acid JO - Bot. Acta PY - 1997 SP - 101-108 AU - Feussner, I. AU - Fritz, I. G. AU - Hause, B. AU - Ullrich, W. R. AU - Wasternack, C. AU - VL - 110 UR - DO - 10.1111/j.1438-8677.1997.tb00616.x AB - Changes in lipoxygenase (LOX) protein pattern and/or activity were investigated in relation to acquired resistance of cucumber (Cucumis sativus L.) leaves against two powdery mildews, Sphaerotheca fuliginea (Schlecht) Salmon and Erysiphe cichoracearum DC et Merat. Acquired resistance was established by spraying leaves with salicylic acid (SA) or 2,6‐dichloroisonicotinic acid (INA) and estimated in whole plants by infested leaf area compared to control plants. SA was more effective than INA. According to Western blots, untreated cucumber leaves contained a 97 kDa LOX form, which remained unchanged for up to 48 h after pathogen inoculation. Upon treatment with SA alone for 24 h or with INA plus pathogen, an additional 95 kDa LOX form appeared which had an isoelectric point in the alkaline range. For the induction of this form, a threshold concentration of 1 mM SA was required, higher SA concentrations did not change LOX‐95 expression which remained similar between 24 h and 96 h but further increased upon mildew inoculation. Phloem exudates contained only the LOX‐97 form, in intercellular washing fluid no LOX was detected. dichloroisonicotinic localization revealed LOX protein in the cytosol of the mesophyll cells without differences between the forms. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 2385 TI - Do specific linoleate 13-lipoxygenases initiate β-oxidation? JO - FEBS Lett. PY - 1997 SP - 1-5 AU - Feussner, I. AU - Kühn, H. AU - Wasternack, C. AU - VL - 406 UR - DO - 10.1016/S0014-5793(97)00218-4 AB - The germination process of oilseed plants is characterized by a mobilization of the storage lipids which constitute the major carbon source for the growing seedling. Despite the physiological importance of the lipid mobilization, the mechanism of this process is not well understood. Recently, it was found that a specific linoleate 13-lipoxygenase is induced during the stage of lipid mobilization in various oilseed plants and that this enzyme is translocated to the membranes of the lipid storage organelles, the so called lipid bodies. Lipoxygenase expression was paralleled by the occurrence of enantiospecific hydro(pero)xy polyenoic fatty acid derivatives in the storage lipids suggesting the in vivo action of the enzyme. Furthermore, it was reported that oxygenated polyenoic fatty acids, in particular as 13(S)-hydro(pero)xy-9(Z),11(E)-octadecanoic acid [13(S)-H(P)ODE], are cleaved preferentially from the storage lipids when compared with their non-oxygenated linoleate residues. These findings may suggest that 13(S)-H(P)ODE may constitute the endogenous substrate for β-oxidation during lipid mobilization of oilseed plants. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2425 TI - Purification and Characterization of Allene Oxide Cyclase from Dry Corn Seeds JO - Plant Physiol. PY - 1997 SP - 565-573 AU - Ziegler, J. AU - Hamberg, M. AU - Miersch, O. AU - Parthier, B. AU - VL - 114 UR - DO - 10.1104/pp.114.2.565 AB - Allene oxide cyclase (AOC; EC 5.3.99.6) catalyzes the cyclization of 12,13(S)-epoxy-9(Z),11,15(Z)-octadecatrienoic acid to 12-oxo- 10,15(Z)-phytodienoic acid, the precursor of jasmonic acid (JA). This soluble enzyme was purified 2000-fold from dry corn (Zea mays L.) kernels to apparent homogeneity. The dimeric protein has a molecular mass of 47 kD. Allene oxide cyclase activity was not affected by divalent ions and was not feedback-regulated by its product, 12-oxo-l0,15(Z)-phytodienoic acid, or by JA. ([plus or minus])-cis- 12,13-Epoxy-9(Z)-octadecenoic acid, a substrate analog, strongly inhibited the enzyme, with 50% inhibition at 20 [mu]M. Modification of the inhibitor, such as methylation of the carboxyl group or a shift in the position of the epoxy group, abolished the inhibitory effect, indicating that both structural elements and their position are essential for binding to AOC. Nonsteroidal anti-inflammatory drugs, which are often used to interfere with JA biosynthesis, did not influence AOC activity. The purified enzyme catalyzed the cyclization of 12,13(S)-epoxy-9(Z),11,15(Z)-octadecatrienoic acid derived from linolenic acid, but not that of 12,13(S)-epoxy-9(Z),11- octadecadienoic acid derived from linoleic acid. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 2424 TI - Concentration of Dilute Protein Solutions Prior to Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis JO - Anal. Biochem. PY - 1997 SP - 257-260 AU - Ziegler, J. AU - Vogt, T. AU - Miersch, O. AU - Strack, D. AU - VL - 250 UR - DO - 10.1006/abio.1997.2248 AB - A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - CHAP ID - 185 TI - Allene Oxide Cyclase from Corn: Partial Purification and Characterization T2 - Physiology, Biochemistry and Molecular Biology of Plant Lipids PB - PY - 1997 SP - 99-101 AU - Ziegler, J. AU - Hamberg, M. AU - Miersch, O. AU - VL - UR - DO - 10.1007/978-94-017-2662-7_32 AB - In plants, the oxylipin pathway gives rise to several oxygenated fatty acid derivatives such as hydroxy- and keto fatty acids as well as volatile aldehydes and cyclic compounds, which are, in part, physiologically active [1]. Among these, jasmonic acid is discussed as signalling molecule during several stress responses, wounding, senescense and plant pathogen interactions [2]. A2 - C1 - Molecular Signal Processing ER - TY - CHAP ID - 181 TI - Do Lipoxygenases Initiate β-Oxidation? T2 - Physiology, Biochemistry and Molecular Biology of Plant Lipids PB - PY - 1997 SP - 250-252 AU - Feussner, I. AU - Kühn, H. AU - Wasternack, C. AU - VL - UR - DO - 10.1007/978-94-017-2662-7_79 AB - The etiolated germination process of oilseed plants is characterized by the mobilization of storage lipids which serve as a major carbon source for the seedlings growth. During this stage the lipid storing organelles, the lipid bodies, are degraded and a new set of proteins, including a specific form of lipoxygenase (LOX), is detectable at their membranes in different plants [1,2]. LOXs are widely distributed in plants and animals and catalyze the regio- and stereo-specific oxygenation of polyunsaturated fatty acids [3]. The enzymatic transformations of the resulting fatty acid hydroperoxides have been extensively studied [4]. Three well characterized enzymes, a lyase, an allene oxide synthase, and a peroxygenase, were shown to degrade hydroperoxides into compounds of physiological importance, such as odors, oxylipins, and jasmonates. We have recently reported a new LOX reaction in plants where a specific LOX, the lipid body LOX, metabolizes esterified fatty acids. This reaction resulted in the formation of 13(S)-hydroxy-linoleic acid (13-HODE) and lead us to propose an additional branch of the LOX pathway: the reductase pathway. Besides a specific LOX form we suggest two additional enzyme activities, a lipid hydroperoxide reductase and a lipid hydroxide-specific lipase which lead to the formation of 13-HODE. 13-HODE might be the endogenous substrate for β-oxidation in the glyoxysomes during germination of oilseeds containing high amounts of polyunsaturated fatty acids. A2 - C1 - Molecular Signal Processing ER -