TY - JOUR ID - 11105 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 - JOUR ID - 11324 TI - Applied jasmonates accumulate extracellularly in tomato, but intracellularly in barley JO - FEBS Lett. PY - 2004 SP - 45-50 AU - Bücking, H. AU - Förster, H. AU - Stenzel, I. AU - Miersch, O. AU - Hause, B. AU - VL - 562 UR - DO - 10.1016/S0014-5793(04)00178-4 AB - Jasmonic acid (JA) and its derivatives are well‐characterized signaling molecules in plant defense and development, but the site of their localization within plant tissue is entirely unknown. To address the question whether applied JA accumulates extracellularly or intracellularly, leaves of tomato and barley were fed with 14C‐labeled JA and the label was localized in cryofixed and lyophilized leaf tissues by microautoradiography. In tomato the radioactivity was detectable within the apoplast, but no label was found within the mesophyll cells. By contrast, in barley leaf tissues, radioactivity was detected within the mesophyll cells suggesting a cellular uptake of exogenously applied JA. JA, applied to leaves of both plants as in the labeling experiments, led in all leaf cells to the expression of JA‐inducible genes indicating that the perception is completed by JA signal transduction. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 11657 TI - Wounding and chemicals induce expression of the Arabidopsis thaliana gene Thi2.1, encoding a fungal defense thionin, via the octadecanoid pathway JO - FEBS Lett. PY - 1998 SP - 281-286 AU - Bohlmann, H. AU - Vignutelli, A. AU - Hilpert, B. AU - Miersch, O. AU - Wasternack, C. AU - Apel, K. AU - VL - 437 UR - DO - 10.1016/S0014-5793(98)01251-4 AB - In seedlings of Arabidopsis thaliana the thionin gene Thi2.1 is inducible by methyl jasmonate, wounding, silver nitrate, coronatine, and sorbitol. We have used a biochemical and genetic approach to test the signal transduction of these different inducers. Both exogenously applied jasmonates and jasmonates produced endogenously upon stress induction, lead to GUS expression in a Thi2.1 promoter-uidA transgenic line. No GUS expression was observed in a coi1 mutant background which lacks jasmonate perception whereas methyl jasmonate and coronatine but not the other inducers were able to overcome the block in jasmonic acid production in a fad3-2 fad7-2 fad8 mutant background. Our results show conclusively that all these inducers regulate Thi2-1 gene expression via the octadecanoid pathway. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 11715 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 - 11711 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 -