TY - JOUR ID - 1833 TI - Jasmonates: An Update on Biosynthesis, Signal Transduction and Action in Plant Stress Response, Growth and Development JO - Ann. Bot. PY - 2007 SP - 681-697 AU - Wasternack, C. AU - VL - 100 UR - DO - 10.1093/aob/mcm079 AB - BackgroundJasmonates are ubiquitously occurring lipid-derived compounds with signal functions in plant responses to abiotic and biotic stresses, as well as in plant growth and development. Jasmonic acid and its various metabolites are members of the oxylipin family. Many of them alter gene expression positively or negatively in a regulatory network with synergistic and antagonistic effects in relation to other plant hormones such as salicylate, auxin, ethylene and abscisic acid.ScopeThis review summarizes biosynthesis and signal transduction of jasmonates with emphasis on new findings in relation to enzymes, their crystal structure, new compounds detected in the oxylipin and jasmonate families, and newly found functions.ConclusionsCrystal structure of enzymes in jasmonate biosynthesis, increasing number of jasmonate metabolites and newly identified components of the jasmonate signal-transduction pathway, including specifically acting transcription factors, have led to new insights into jasmonate action, but its receptor(s) is/are still missing, in contrast to all other plant hormones. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1832 TI - Clarence A. “Bud” Ryan (29.09.1931–07.10.2007) JO - Plant Mol. Biol. PY - 2007 SP - 709-709 AU - Wasternack, C. AU - VL - 65 UR - DO - 10.1007/s11103-007-9254-8 AB - A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1830 TI - Endogenous jasmonates in dry and imbibed sunflower seeds from plants grown at different soil moisture contents JO - Seed Sci. Res. PY - 2007 SP - 91-98 AU - Vigliocco, A. AU - Alemano, S. AU - Miersch, O. AU - Alvarez, D. AU - Abdala, G. AU - VL - 17 UR - DO - 10.1017/S0960258507708371 AB - In this study, we characterized two sunflower (Helianthus annuus L.) lines with differential sensitivity to drought, the sensitive line B59 and the tolerant line B71. Using both lines, we compared the content of endogenous jasmonates (JAs) in dry and imbibed seeds from plants grown under irrigation and drought. Jasmonic acid (JA), 12-oxo-phytodienoic acid (OPDA), 11-hydroxyjasmonate (11-OH-JA) and 12-hydroxyjasmonate (12-OH-JA) were detected in dry and imbibed sunflower seeds. Seeds from plants grown under drought had a lower content of total JAs and exhibited higher germination percentages than seeds from irrigated plants, demonstrating that environmental conditions have a strong influence on the progeny. OPDA and 12-OH-JA were the main compounds found in dry seeds of both lines. Imbibed seeds showed an enhanced amount of total JAs with respect to dry seeds produced by plants grown in both soil moisture conditions. Imbibition triggered a dramatic OPDA increase in the embryo, suggesting a role of this compound in germination. We conclude that JAs patterns vary during sunflower germination and that the environmental conditions experienced by the mother plant modify the hormonal content of the seed progeny. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1823 TI - Immunomodulation of jasmonate to manipulate the wound response JO - J. Exp. Bot. PY - 2007 SP - 2525-2535 AU - ten Hoopen, P. AU - Hunger, A. AU - Muller, A. AU - Hause, B. AU - Kramell, R. AU - Wasternack, C. AU - Rosahl, S. AU - Conrad, U. AU - VL - 58 UR - DO - 10.1093/jxb/erm122 AB - Jasmonates are signals in plant stress responses and development. The exact mode of their action is still controversial. To modulate jasmonate levels intracellularly as well as compartment-specifically, transgenic Nicotiana tabacum plants expressing single-chain antibodies selected against the naturally occurring (3R,7R)-enantiomer of jasmonic acid (JA) were created in the cytosol and the endoplasmic reticulum. Consequently, the expression of anti-JA antibodies in planta caused JA-deficient phenotypes such as insensitivity of germinating transgenic seedlings towards methyl jasmonate and the loss of wound-induced gene expression. Results presented here suggest an essential role for cytosolic JA in the wound response of tobacco plants. The findings support the view that substrate availability takes part in regulating JA biosynthesis upon wounding. Moreover, high JA levels observed in immunomodulated plants in response to wounding suggest that tobacco plants are able to perceive a reduced level of physiologically active JA and attempt to compensate for this by increased JA accumulation. A2 - C1 - Cell and Metabolic Biology; Molecular Signal Processing; Biochemistry of Plant Interactions ER - TY - JOUR ID - 1821 TI - Mechanism of auxin perception by the TIR1 ubiquitin ligase JO - Nature PY - 2007 SP - 640-645 AU - Tan, X. AU - Calderon-Villalobos, L. I. A. AU - Sharon, M. AU - Zheng, C. AU - Robinson, C. V. AU - Estelle, M. AU - Zheng, N. AU - VL - 446 UR - DO - 10.1038/nature05731 AB - Auxin is a pivotal plant hormone that controls many aspects of plant growth and development. Perceived by a small family of F-box proteins including transport inhibitor response 1 (TIR1), auxin regulates gene expression by promoting SCF ubiquitin-ligase-catalysed degradation of the Aux/IAA transcription repressors, but how the TIR1 F-box protein senses and becomes activated by auxin remains unclear. Here we present the crystal structures of the Arabidopsis TIR1–ASK1 complex, free and in complexes with three different auxin compounds and an Aux/IAA substrate peptide. These structures show that the leucine-rich repeat domain of TIR1 contains an unexpected inositol hexakisphosphate co-factor and recognizes auxin and the Aux/IAA polypeptide substrate through a single surface pocket. Anchored to the base of the TIR1 pocket, auxin binds to a partially promiscuous site, which can also accommodate various auxin analogues. Docked on top of auxin, the Aux/IAA substrate peptide occupies the rest of the TIR1 pocket and completely encloses the hormone-binding site. By filling in a hydrophobic cavity at the protein interface, auxin enhances the TIR1–substrate interactions by acting as a ‘molecular glue’. Our results establish the first structural model of a plant hormone receptor. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1817 TI - Characterization of the VIER F-BOX PROTEINE Genes from Arabidopsis Reveals Their Importance for Plant Growth and Development JO - Plant Cell PY - 2007 SP - 1163-1178 AU - Schwager, K. M. AU - Calderon-Villalobos, L. I. A. AU - Dohmann, E. M. AU - Willige, B. C. AU - Knierer, S. AU - Nill, C. AU - Schwechheimer, C. AU - VL - 19 UR - DO - 10.1105/tpc.105.040675 AB - E3 ubiquitin ligases (E3s) target proteins for degradation by the 26S proteasome. In SKP1/CDC53/F-box protein–type E3s, substrate specificity is conferred by the interchangeable F-box protein subunit. The vast majority of the 694 F-box proteins encoded by the Arabidopsis thaliana genome remain to be understood. We characterize the VIER F-BOX PROTEINE (VFB; German for FOUR F-BOX PROTEINS) genes from Arabidopsis that belong to subfamily C of the Arabidopsis F-box protein superfamily. This subfamily also includes the F-box proteins TRANSPORT INHIBITOR RESPONSE1 (TIR1)/AUXIN SIGNALING F-BOX (AFB) proteins and EIN3 BINDING F-BOX proteins, which regulate auxin and ethylene responses, respectively. We show that loss of VFB function causes delayed plant growth and reduced lateral root formation. We find that the expression of a number of auxin-responsive genes and the activity of DR5:β-glucuronidase, a reporter for auxin reponse, are reduced in the vfb mutants. This finding correlates with an increase in the abundance of an AUXIN/INDOLE-3-ACETIC ACID repressor. However, we also find that auxin responses are not affected in the vfb mutants and that a representative VFB family member, VFB2, cannot functionally complement the tir1-1 mutant. We therefore exclude the possibility that VFBs are functional orthologs of TIR1/AFB proteins. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1814 TI - Isolation and characterization of the glutaminyl cyclases from Solanum tuberosum and Arabidopsis thaliana: implications for physiological functions JO - Biol. Chem. PY - 2007 SP - 145-153 AU - Schilling, S. AU - Stenzel, I. AU - von Bohlen, A. AU - Wermann, M. AU - Schulz, K. AU - Demuth, H.-U. AU - Wasternack, C. AU - VL - 388 UR - DO - 10.1515/BC.2007.016 AB - Glutaminyl cyclases (QCs) catalyze the formation of pyroglutamic acid at the N-terminus of several peptides and proteins. On the basis of the amino acid sequence of Carica papaya QC, we identified cDNAs of the putative counterparts from Solanum tuberosum and Arabidopsis thaliana. Upon expression of the corresponding cDNAs from both plants via the secretory pathway of Pichia pastoris, two active QC proteins were isolated. The specificity of the purified proteins was assessed using various substrates with different amino acid composition and length. Highest specificities were observed with substrates possessing large hydrophobic residues adjacent to the N-terminal glutamine and for fluorogenic dipeptide surrogates. However, compared to Carica papaya QC, the specificity constants were approximately one order of magnitude lower for most of the QC substrates analyzed. The QCs also catalyzed the conversion of N-terminal glutamic acid to pyroglutamic acid, but with approximately 105- to 106-fold lower specificity. The ubiquitous distribution of plant QCs prompted a search for potential substrates in plants. Based on database entries, numerous proteins, e.g., pathogenesis-related proteins, were found that carry a pyroglutamate residue at the N-terminus, suggesting QC involvement. The putative relevance of QCs and pyroglutamic acid for plant defense reactions is discussed. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1777 TI - Chrysanthemum Chlorotic Mottle Viroid: a System for Reverse Genetics in the Family Avsunviroidae (Hammerhead Viroids) JO - Plant Viruses PY - 2007 SP - 27-32 AU - Flores, R. AU - Navarro, B. AU - Gago, S. AU - De la Peña, M. AU - VL - 1 UR - http://www.globalsciencebooks.info/Online/GSBOnline/OnlinePV_1_1.html AB - Viroids are small single-stranded circular RNAs able to infect plants. Chrysanthemum chlorotic mottle was one of the first viroid diseases reported, but identification and characterization of the causing RNA was delayed by its low accumulation in vivo. Chrysanthemum chlorotic mottle viroid (CChMVd) (398-401 nt) adopts a branched conformation instead of the rod-like secondary structure characteristic of most viroids. The natural sequence variability and the effects of artificial mutants support that the branched conformation is physiologically relevant and additionally stabilized by a kissing-loop interaction critical for RNA in vitro folding and in vivo viability. CChMVd shares structural similarities with peach latent mosaic viroid, with which forms the genus Pelamoviroid within the family Avsunviroidae. CChMVd adopts hammerhead structures that catalyze self-cleavage of the oligomeric strands of both polarities resulting from replication through a symmetric rolling-circle mechanism. The two CChMVd hammerheads display peculiarities: the plus has an extra A close to the central conserved core, and the minus an unsually long helix II. There are non-symptomatic strains (CChMVd-NS) that protect against challenge inoculation with severe strains (CChMVd-S). Introduction by site-directed mutagenesis of one of the CChMVd-NS specific mutations (UUUC?GAAA) is sufficient to change the symptomatic phenotype into non-symptomatic without altering the viroid titer. This pathogenicity determinant maps at a tetraloop of the CChMVd branched conformation. Co-inoculations with typical CChMVd-S and -NS variants showed that the infected plants remain symptomless only when the latter was in more than a 100-fold excess, indicating the higher fitness of the S variant. RNA silencing could mediate the observed cross-protection. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1776 TI - “Chromoplast” development in arbuscular mycorrhizal roots JO - Phytochemistry PY - 2007 SP - 92-100 AU - Fester, T. AU - Lohse, S. AU - Halfmann, K. AU - VL - 68 UR - DO - 10.1016/j.phytochem.2006.09.034 AB - The accumulation of apocarotenoids in arbuscular mycorrhizal (AM) roots suggests a dramatic reorganization of the plastids responsible for the biosynthesis of these compounds. This review describes the cytological and biochemical characterization of this phenomenon. The results presented suggest that plastids are key organelles for the establishment of the symbiotic interface of the AM symbiosis. In addition, a complex interplay of various plant cell components during the different functional phases of this interface is suggested. Arbuscule degradation appears to be of particular interest, as it correlates with the formation of the most extensive plastid structures and with apocarotenoid accumulation. A2 - C1 - Cell and Metabolic Biology; Molecular Signal Processing ER - TY - JOUR ID - 1774 TI - Reduction of divinyl ether-containing polyunsaturated fatty acids in transgenic potato plants JO - Phytochemistry PY - 2007 SP - 797-801 AU - Eschen-Lippold, L. AU - Rothe, G. AU - Stumpe, M. AU - Göbel, C. AU - Feussner, I. AU - Rosahl, S. AU - VL - 68 UR - DO - 10.1016/j.phytochem.2006.12.010 AB - Oxygenated polyunsaturated fatty acids synthesized via the lipoxygenase pathway play a role in plant responses to pathogen attack. In solanaceous plants, the preferential stimulation of the 9-lipoxygenase pathway in response to pathogen infection leads to the formation of the divinyl ether-containing polyunsaturated fatty acids colneleic and colnelenic acid, as well as hydroxy and trihydroxy polyunsaturated fatty acids. To functionally assess the role of divinyl ethers, transgenic potato plants were generated which express an RNA interference construct directed against the pathogen-inducible 9-divinyl ether synthase. Efficient reduction of 9-divinyl ether synthase transcript accumulation correlated with reduced levels of colneleic and colnelenic acid. However, in response to infection with virulent Phytophthora infestans, the causal agent of late blight disease, no significant differences in pathogen biomass could be detected suggesting that the levels of antimicrobial divinyl ethers are not critical for defense against Phytophthora infestans in a compatible interaction. A2 - C1 - Molecular Signal Processing; Biochemistry of Plant Interactions ER - TY - JOUR ID - 1773 TI - Chronobiological phenomena and seasonal changes in jasmonate levels during the course of the year and under constant conditions in mistletoe (Viscum album L.) JO - Phytomedicine PY - 2007 SP - 15 AU - Dorka, R. AU - Miersch, O. AU - Wasternack, C. AU - Weik, P. AU - VL - 14 UR - DO - 10.1016/j.phymed.2007.07.014 AB - A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1769 TI - Jasmonate biosynthesis in Arabidopsis thaliana requires peroxisomal β-oxidation enzymes – Additional proof by properties of pex6 and aim1 JO - Phytochemistry PY - 2007 SP - 1642-1650 AU - Delker, C. AU - Zolman, B. K. AU - Miersch, O. AU - Wasternack, C. AU - VL - 68 UR - DO - 10.1016/j.phytochem.2007.04.024 AB - Jasmonic acid (JA) is an important regulator of plant development and stress responses. Several enzymes involved in the biosynthesis of JA from α-linolenic acid have been characterized. The final biosynthesis steps are the β-oxidation of 12-oxo-phytoenoic acid. We analyzed JA biosynthesis in the Arabidopsis mutants pex6, affected in peroxisome biogenesis, and aim1, disrupted in fatty acid β-oxidation. Upon wounding, these mutants exhibit reduced JA levels compared to wild type. pex6 accumulated the precursor OPDA. Feeding experiments with deuterated OPDA substantiate this accumulation pattern, suggesting the mutants are impaired in the β-oxidation of JA biosynthesis at different steps. Decreased expression of JA-responsive genes, such as VSP1, VSP2, AtJRG21 and LOX2, following wounding in the mutants compared to the wild type reflects the reduced JA levels of the mutants. By use of these additional mutants in combination with feeding experiments, the necessity of functional peroxisomes for JA-biosynthesis is confirmed. Furthermore an essential function of one of the two multifunctional proteins of fatty acid β-oxidation (AIM1) for wound-induced JA formation is demonstrated for the first time. These data confirm that JA biosynthesis occurs via peroxisomal fatty acid β-oxidation machinery. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1765 TI - The evolutionarily conserved Arabidopsis thaliana F-box protein AtFBP7 is required for efficient translation during temperature stress JO - Gene PY - 2007 SP - 106-116 AU - Calderon-Villalobos, L. I. A. AU - Nill, C. AU - Marrocco, K. AU - Kretsch, T. AU - Schwechheimer, C. AU - VL - 392 UR - DO - 10.1016/j.gene.2006.11.016 AB - In eukaryotes, E3 ubiquitin ligases (E3s) mediate the ubiquitylation of proteins that are destined for degradation by the ubiquitin–proteasome system. In SKP1/CDC53/F-box protein (SCF)-type E3 complexes, the interchangeable F-box protein confers specificity to the E3 ligase through direct physical interactions with the degradation substrate. The vast majority of the approximately 700 F-box proteins from the plant model organism Arabidopsis thaliana remain to be characterized. Here, we investigate the previously uncharacterized and evolutionarily conserved Arabidopsis F-box protein 7 (AtFBP7), which is encoded by a unique gene in Arabidopsis (At1g21760). Several apparent fbp7 loss-of-function alleles do not have an obvious phenotype. AtFBP7 is ubiquitously expressed and its expression is induced after cold and heat stress. When following up on a reported co-purification of the eukaryotic elongation factor-2 (eEF-2) with YLR097c, the apparent budding yeast orthologue of AtFBP7, we discovered a general defect in protein biosynthesis after cold and heat stress in fbp7 mutants. Thus, our findings suggest that AtFBP7 is required for protein synthesis during temperature stress. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1760 TI - Catalytic activity of hammerhead ribozymes in a clay mineral environment: Implications for the RNA world JO - Gene PY - 2007 SP - 10-18 AU - Biondi, E. AU - Branciamore, S. AU - Fusi, L. AU - Gago, S. AU - Gallori, E. AU - VL - 389 UR - DO - 10.1016/j.gene.2006.09.002 AB - The hypothesized RNA-based world would have required the presence of a protected environment in which RNA, or an RNA-like molecule, could originate and express its biological activity.Recent studies have indicated that RNA molecules adsorbed/bound on clay minerals are able to persist in the presence of degrading agents, to interact with surrounding molecules, and to transmit the information contained in their nucleotide sequences.In this study, we assessed the ability of RNA molecules with catalytic activity to perform a specific reaction in a mineral environment. For this purpose, we investigated the self-cleavage reaction of the hammerhead ribozyme of the Avocado Sun Blotch Viroid (ASBVd), both in the monomeric and in dimeric forms. The monomeric transcript was tightly bound on the clay mineral montmorillonite to form a stable complex, while the behaviour of the dimeric transcript was studied in the presence of the clay particles in the reaction mixture.The results indicated that the hammerhead ribozyme was still active when the monomeric transcript was adsorbed on the clay surface, even though its efficiency was reduced to about 20% of that in solution. Moreover, the self-cleavage of clay-adsorbed molecule was significantly enhanced (∼ four times) by the presence of the 5′ reaction product.The self-cleavage reaction of the dimeric transcript in the presence of montmorillonite indicated that the mineral particles protected the RNA molecules against aspecific degradation and increased the rate of cleavage kinetics by about one order of magnitude.These findings corroborate the hypothesis that clay-rich environments would have been a good habitat in which RNA or RNA-like molecules could originate, accumulate and undergo Darwinian evolutionary processes, leading to the first living cells on Earth. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1755 TI - Auxin Is Surfacing JO - ACS Chem. Biol. PY - 2007 SP - 380-384 AU - Abel, S. AU - VL - 2 UR - DO - 10.1021/cb7001158 AB - Indole-3-acetic acid (IAA or auxin) is essential throughout the life cycle of a plant. It controls diverse cellular processes, including gene expression. The hormone is perceived by a ubiquitin protein ligase (E3) and triggers the rapid destruction of repressors, called Aux/IAA proteins. The first structural model of a plant hormone receptor illustrates how auxin promotes Aux/IAA substrate recruitment by extending the hydrophobic protein-interaction surface. This work establishes a novel mechanism of E3 regulation by small molecules and promises a novel strategy for the treatment of human disorders associated with defective ubiquitin-dependent proteolysis. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1806 TI - Cold and water stresses produce changes in endogenous jasmonates in two populations of Pinus pinaster Ait JO - Plant Growth Regul. PY - 2007 SP - 111-116 AU - Pedranzani, H. AU - Sierra-de-Grado, R. AU - Vigliocco, A. AU - Miersch, O. AU - Abdala, G. AU - VL - 52 UR - DO - 10.1007/s10725-007-9166-2 AB - There is considerable evidence suggesting that jasmonates (JAs) play a role in plant resistance against abiotic stress. It is well known that in Angiosperms JAs are involved in the defense response, however there is little information about their role in Gymnosperms. Our proposal was to study the involvement of JAs in Pinus pinaster Ait. reaction to cold and water stress, and to compare the response of two populations of different provenances (Gredos and Bajo Tiétar) to these stresses. We detected 12-oxo-phytodienoic acid (OPDA), jasmonic acid (JA), and the hydroxylates 11-hydroxyjasmonate and 12-hydroxyjasmonate in foliage and shoots of P. pinaster plants. The response of the Gredos population to cold stress differed from that of Bajo Tiétar. Gredos plants showed a lower JA-basal level than Bajo Tiétar; under cold stress JA increased twofold at 72 h, while it decreased in Bajo Tiétar plants. The hydroxylates slightly increased in both populations due to cold stress treatment. Under water stress, plants from Gredos showed a remarkable JA-increase; thus the JA-response was much more prominent under water stress than under cold stress. In contrast, no change was found in JA-level in Bajo Tiétar plants under water stress. The level of JA-precursor, OPDA, was very low in control plants from Gredos and Bajo Tiétar. Under water stress OPDA increased only in plants from Bajo Tiétar. Therefore, we inform here of a different JAs-accumulation pattern after the stress treatment in P. pinaster from two provenances, and suggest a possible correlation with adaptations to diverse ecological conditions. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1794 TI - The Jasmonate-Induced Expression of the Nicotiana tabacum Leaf Lectin JO - Plant Cell Physiol. PY - 2007 SP - 1207-1218 AU - Lannoo, N. AU - Vandenborre, G. AU - Miersch, O. AU - Smagghe, G. AU - Wasternack, C. AU - Peumans, W. J. AU - Van Damme, E. J. M. AU - VL - 48 UR - DO - 10.1093/pcp/pcm090 AB - Previous experiments with tobacco (Nicotiana tabacum L. cv Samsun NN) plants revealed that jasmonic acid methyl ester (JAME) induces the expression of a cytoplasmic/nuclear lectin in leaf cells and provided the first evidence that jasmonates affect the expression of carbohydrate-binding proteins in plant cells. To corroborate the induced accumulation of relatively large amounts of a cytoplasmic/nuclear lectin, a detailed study was performed on the induction of the lectin in both intact tobacco plants and excised leaves. Experiments with different stress factors demonstrated that the lectin is exclusively induced by exogeneously applied jasmonic acid and JAME, and to a lesser extent by insect herbivory. The lectin concentration depends on leaf age and the position of the tissue in the leaf. JAME acts systemically in intact plants but very locally in excised leaves. Kinetic analyses indicated that the lectin is synthesized within 12 h exposure time to JAME, reaching a maximum after 60 h. After removal of JAME, the lectin progressively disappears from the leaf tissue. The JAME-induced accumulation of an abundant nuclear/cytoplasmic lectin is discussed in view of the possible role of this lectin in the plant. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1785 TI - Substrate specificity and products of side-reactions catalyzed by jasmonate:amino acid synthetase (JAR1) JO - FEBS Lett. PY - 2007 SP - 815-820 AU - Guranowski, A. AU - Miersch, O. AU - Staswick, P. E. AU - Suza, W. AU - Wasternack, C. AU - VL - 581 UR - DO - 10.1016/j.febslet.2007.01.049 AB - Jasmonate:amino acid synthetase (JAR1) is involved in the function of jasmonic acid (JA) as a plant hormone. It catalyzes the synthesis of several JA‐amido conjugates, the most important of which appears to be JA‐Ile. Structurally, JAR1 is a member of the firefly luciferase superfamily that comprises enzymes that adenylate various organic acids. This study analyzed the substrate specificity of recombinant JAR1 and determined whether it catalyzes the synthesis of mono‐ and dinucleoside polyphosphates, which are side‐reaction products of many enzymes forming acyl ∼ adenylates. Among different oxylipins tested as mixed stereoisomers for substrate activity with JAR1, the highest rate of conversion to Ile‐conjugates was observed for (±)‐JA and 9,10‐dihydro‐JA, while the rate of conjugation with 12‐hydroxy‐JA and OPC‐4 (3‐oxo‐2‐(2Z ‐pentenyl)cyclopentane‐1‐butyric acid) was only about 1–2% that for (±)‐JA. Of the two stereoisomers of JA, (−)‐JA and (+)‐JA, rate of synthesis of the former was about 100‐fold faster than for (+)‐JA. Finally, we have demonstrated that (1) in the presence of ATP, Mg2+, (−)‐JA and tripolyphosphate the ligase produces adenosine 5′‐tetraphosphate (p4A); (2) addition of isoleucine to that mixture halts the p4A synthesis; (3) the enzyme produces neither diadenosine triphosphate (Ap3A) nor diadenosine tetraphosphate (Ap4A) and (4) Ap4A cannot substitute ATP as a source of adenylate in the complete reaction that yields JA‐Ile. A2 - C1 - Cell and Metabolic Biology; Molecular Signal Processing ER - TY - CHAP ID - 118 TI - Jasmonate signaling in tomato – The input of tissue-specific occurrence of allene oxide cyclase and JA metabolites T2 - Proceeding of the 17th Int. Symp. on Plant Lipids PB - PY - 2007 SP - 107-111 AU - Wasternack, C. AU - Hause, B. AU - Stenzel, I. AU - Goetz, S. AU - Feussner, I. AU - Miersch, O. AU - VL - UR - AB - A2 - Benning C., Ollrogge, J. C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - CHAP ID - 112 TI - RNAs Autocatalíticos: Ribozimas de Cabeza de Martillo T2 - Herramientas Biotecnológicas en Fitopatología PB - PY - 2007 SP - 407-425 AU - Flores, R. AU - Carbonell, A. AU - De la Peña, M. AU - Gago, S. AU - VL - UR - AB - A2 - C1 - Molecular Signal Processing ER -