@Article{IPB-1219, author = {Sreenivasulu, N. and Radchuk, V. and Alawady, A. and Borisjuk, L. and Weier, D. and Staroske, N. and Fuchs, J. and Miersch, O. and Strickert, M. and Usadel, B. and Wobus, U. and Grimm, B. and Weber, H. and Weschke, W.}, title = {{De-regulation of abscisic acid contents causes abnormal endosperm development in the barley mutant seg8}}, year = {2010}, pages = {589-603}, journal = {Plant J}, doi = {10.1111/j.1365-313X.2010.04350.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2010.04350.x/abstract}, volume = {64(4)}, abstract = {Grain development of the maternal effect shrunken endosperm mutant seg8 was analysed by comprehensive molecular, biochemical and histological methods. The most obvious finding was de-regulation of ABA levels, which were lower compared to wild-type during the pre-storage phase but higher during the transition from cell division/differentiation to accumulation of storage products. Ploidy levels and ABA amounts were inversely correlated in the developing endosperms of both mutant and wild-type, suggesting an influence of ABA on cell-cycle regulation. The low ABA levels found in seg8 grains between anthesis and beginning endosperm cellularization may result from a gene dosage effect in the syncytial endosperm that causes impaired transfer of ABA synthesized in vegetative tissues into filial grain parts. Increased ABA levels during the transition phase are accompanied by higher chlorophyll and carotenoid/xanthophyll contents. The data suggest a disturbed ABA-releasing biosynthetic pathway. This is indicated by up-regulation of expression of the geranylgeranyl reductase (GGR) gene, which may be induced by ABA deficiency during the pre-storage phase. Abnormal cellularization/differentiation of the developing seg8 endosperm and reduced accumulation of starch are phenotypic characteristics that reflect these disturbances. The present study did not reveal the primary gene defect causing the seg8 phenotype, but presents new insights into the maternal/filial relationships regulating barley endosperm development.} } @Article{IPB-1206, author = {Stumpe, M. and Göbel, C. and Faltin, B. and Beike, A. K. and Hause, B. and Himmelsbach, K. and Bode, J. and Kramell, R. and Wasternack, C. and Frank, W. and Reski, R. and Feussner, I.}, title = {{The moss Physcomitrella patens contains cyclopentenones but no jasmonates: mutations in allene oxide cyclase lead to reduced fertility and altered sporophyte morphology}}, year = {2010}, pages = {740-749}, journal = {New Phytol}, doi = {10.1111/j.1469-8137.2010.03406.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2010.03406.x/abstract}, volume = {188 (3)}, abstract = {Two cDNAs encoding allene oxide cyclases (PpAOC1, PpAOC2), key enzymes in the formation of jasmonic acid (JA) and its precursor (9S,13S)‐12‐oxo‐phytodienoic acid (cis‐(+)‐OPDA), were isolated from the moss Physcomitrella patens.Recombinant PpAOC1 and PpAOC2 show substrate specificity against the allene oxide derived from 13‐hydroperoxy linolenic acid (13‐HPOTE); PpAOC2 also shows substrate specificity against the allene oxide derived from 12‐hydroperoxy arachidonic acid (12‐HPETE).In protonema and gametophores the occurrence of cis‐(+)‐OPDA, but neither JA nor the isoleucine conjugate of JA nor that of cis‐(+)‐OPDA was detected.Targeted knockout mutants for PpAOC1 and for PpAOC2 were generated, while double mutants could not be obtained. The ΔPpAOC1 and ΔPpAOC2 mutants showed reduced fertility, aberrant sporophyte morphology and interrupted sporogenesis.} } @INBOOK{IPB-1497, author = {Yamaguchi, I. and Cohen, J. D. and Culler, A. H. and Quint, M. and Slovin, J. P. and Nakajima, M. and Yamaguchi, S. and Sakakibara, H. and Kuroha, T. and Hirai, N. and Yokota, T. and Ohta, H. and Kobayashi, Y. and Mori, H. and Sakagami, Y.}, title = {{}}, year = {2010}, pages = {9-125}, chapter = {{Plant Hormones}}, journal = {Comprehensive Natural Products II}, editor = {Liu, H.-W. \& Mander, L., eds.}, doi = {10.1016/B978-008045382-8.00092-7}, url = {https://dx.doi.org/10.1016/B978-008045382-8.00092-7}, volume = {4}, abstract = {The definition of a plant hormone has not been clearly established, so the compounds classified as plant hormones often vary depending on which definition is considered. In this chapter, auxins, gibberellins (GAs), cytokinins, abscisic acid, brassinosteroids, jasmonic acid-related compounds, and ethylene are described as established plant hormones, while polyamines and phenolic compounds are not included. On the other hand, several peptides that have been proven to play a clear physiological role(s) in plant growth and development, similar to the established plant hormones, are referred. This chapter will focus primarily on the more recent discoveries of plant hormones and their impact on our current understanding of their biological role. In some cases, however, it is critical to place recent work in a proper historical context.} } @Article{IPB-1160, author = {Wasternack, C. and Kombrink, E.}, title = {{Jasmonates: Structural Requirements for Lipid-Derived Signals Active in Plant Stress Responses and Development}}, year = {2010}, pages = {63-77}, journal = {ACS Chem Biol}, doi = {10.1021/cb900269u}, url = {http://pubs.acs.org/doi/abs/10.1021/cb900269u?journalCode=acbcct&quickLinkVolume=5&quickLinkPage=63&selectedTab=citation&volume=5}, volume = {5}, abstract = {Jasmonates are lipid-derived signals that mediate plant stress responses and development processes. Enzymes participating in biosynthesis of jasmonic acid (JA) (1, 2) and components of JA signaling have been extensively characterized by biochemical and molecular-genetic tools. Mutants of Arabidopsis and tomato have helped to define the pathway for synthesis of jasmonoyl-isoleucine (JA-Ile), the active form of JA, and to identify the F-box protein COI1 as central regulatory unit. However, details of the molecular mechanism of JA signaling have only recently been unraveled by the discovery of JAZ proteins that function in transcriptional repression. The emerging picture of JA perception and signaling cascade implies the SCFCOI1 complex operating as E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S-proteasome pathway, thereby allowing the transcription factor MYC2 to activate gene expression. The fact that only one particular stereoisomer, (+)-7-iso-JA-l-Ile (4), shows high biological activity suggests that epimerization between active and inactive diastereomers could be a mechanism for turning JA signaling on or off. The recent demonstration that COI1 directly binds (+)-7-iso-JA-l-Ile (4) and thus functions as JA receptor revealed that formation of the ternary complex COI1-JA-Ile-JAZ is an ordered process. The pronounced differences in biological activity of JA stereoisomers also imply strict stereospecific control of product formation along the JA biosynthetic pathway. The pathway of JA biosynthesis has been unraveled, and most of the participating enzymes are well-characterized. For key enzymes of JA biosynthesis the crystal structures have been established, allowing insight into the mechanisms of catalysis and modes of substrate binding that lead to formation of stereospecific products.} } @Article{IPB-1187, author = {Wasternack, C. and Xie, D.}, title = {{The genuine ligand of a jasmonic acid receptor: Improved analysis of jasmonates is now required.}}, year = {2010}, pages = {337-340}, journal = {Plant Signal Behav}, doi = {10.4161/psb.5.4.11574}, url = {https://dx.doi.org/10.4161/psb.5.4.11574}, volume = {5}, abstract = {Jasmonic acid (JA), its metabolites, such as the methyl ester or amino acid conjugates as well as its precursor 12-oxophytodienoic acid (OPDA) are lipid-derived signals. JA, OPDA and JA-amino acid conjugates are known to function as signals in plant stress responses and development. More recently, formation of JA-amino acid conjugates and high biological activity of JA-Isoleucine (JA-Ile) were found to be essential in JA signaling. A breakthrough was the identification of JAZ proteins which interact with the F-box protein COI1 if JA-Ile is bound. This interaction leads to proteasomal degradation of JAZs being negative regulators of JA-induced transcription. Surprisingly, a distinct stereoisomer of JA-Ile, the (+)-7-iso-JA-Ile [(3R,7S) form] is most active. Coronatine, a bacterial phytotoxine with an identical stereochemistry at the cyclopentanone ring, has a similar bioactivity. This was explained by the recent identification of COI1 as the JA receptor and accords well with molecular modeling studies. Whereas over the last two decades JA was quantified to describe any JA dependent process, now we have to take into account a distinct stereoisomer of JA-Ile. Until recently a quantitative analysis of (+)-7-iso-JA-Ile was missing presumable due to its equilibration to (−)-JA-Ile. Now such an analysis was achieved. These aspects will be discussed based on our new knowledge on JA perception and signaling.} } @Article{IPB-1189, author = {Robson, F. and Okamoto, H. and Patrick, E. and Harris, S.-R. and Wasternack, C. and Brearley, C. and Turner, J. G.}, title = {{Jasmonate and Phytochrome A Signaling in Arabidopsis Wound and Shade Responses Are Integrated through JAZ1 Stability}}, year = {2010}, pages = {1143-1160}, journal = {Plant Cell}, doi = {10.1105/tpc.109.067728}, url = {https://dx.doi.org/10.1105/tpc.109.067728}, volume = {22}, abstract = {Jasmonate (JA) activates plant defense, promotes pollen maturation, and suppresses plant growth. An emerging theme in JA biology is its involvement in light responses; here, we examine the interdependence of the JA- and light-signaling pathways in Arabidopsis thaliana. We demonstrate that mutants deficient in JA biosynthesis and signaling are deficient in a subset of high irradiance responses in far-red (FR) light. These mutants display exaggerated shade responses to low, but not high, R/FR ratio light, suggesting a role for JA in phytochrome A (phyA) signaling. Additionally, we demonstrate that the FR lightinduced expression of transcription factor genes is dependent on CORONATINE INSENSITIVE1 (COI1), a central component of JA signaling, and is suppressed by JA. phyA mutants had reduced JA-regulated growth inhibition and VSP expression and increased content of cis-(+)-12-oxophytodienoic acid, an intermediate in JA biosynthesis. Significantly, COI1-mediated degradation of JASMONATE ZIM DOMAIN1-b-glucuronidase (JAZ1-GUS) in response to mechanical wounding and JA treatment required phyA, and ectopic expression of JAZ1-GUS resulted in exaggerated shade responses.Together, these results indicate that JA and phyA signaling are integrated through degradation of the JAZ1 protein, and both are required for plant responses to light and stress.} } @INBOOK{IPB-1158, author = {Wasternack, C.}, title = {{Plant Stress Biology: From Genomics to Systems Biology}}, year = {2010}, pages = {91 - 118}, chapter = {{Jasmonates in Stress, Growth, and Development}}, journal = {WILEY-VCH Verlag GmbH \& Co. KGaA, Weinheim}, editor = {H. Hirt}, doi = {10.1002/9783527628964.ch5}, } @Article{IPB-1215, author = {Leon-Reyes, A. and Van der Does, D. and De Lange, E. S. and Delker, C. and Wasternack, C. and Van Wees, S. C. M. and Ritsema, T. and Pieterse, C. M. J.}, title = {{Salicylate-mediated suppression of jasmonate-responsive gene expression in Arabidopsis is targeted downstream of the jasmonate biosynthesis pathway}}, year = {2010}, pages = {1423-1432}, journal = {Planta}, doi = {10.1007/s00425-010-1265-z}, url = {https://dx.doi.org/10.1007/s00425-010-1265-z}, volume = {232}, abstract = {Jasmonates (JAs) and salicylic acid (SA) are plant hormones that play pivotal roles in the regulation of induced defenses against microbial pathogens and insect herbivores. Their signaling pathways cross-communicate providing the plant with a regulatory potential to finely tune its defense response to the attacker(s) encountered. In Arabidopsis thaliana, SA strongly antagonizes the jasmonic acid (JA) signaling pathway, resulting in the downregulation of a large set of JA-responsive genes, including the marker genes PDF1.2 and VSP2. Induction of JA-responsive marker gene expression by different JA derivatives was equally sensitive to SA-mediated suppression. Activation of genes encoding key enzymes in the JA biosynthesis pathway, such as LOX2, AOS, AOC2, and OPR3 was also repressed by SA, suggesting that the JA biosynthesis pathway may be a target for SA-mediated antagonism. To test this, we made use of the mutant aos/dde2, which is completely blocked in its ability to produce JAs because of a mutation in the ALLENE OXIDE SYNTHASE gene. Mutant aos/dde2 plants did not express the JA-responsive marker genes PDF1.2 or VSP2 in response to infection with the necrotrophic fungus Alternaria brassicicola or the herbivorous insect Pieris rapae. Bypassing JA biosynthesis by exogenous application of methyl jasmonate (MeJA) rescued this JA-responsive phenotype in aos/dde2. Application of SA suppressed MeJA-induced PDF1.2 expression to the same level in the aos/dde2 mutant as in wild-type Col-0 plants, indicating that SA-mediated suppression of JAresponsive gene expression is targeted at a position downstream of the JA biosynthesis pathway.} } @Article{IPB-381, author = {Feussner, I. and Hause, B. and Nellen, A. and Wasternack, C. and Kindl, H.}, title = {{Lipid-body lipoxygenase is expressed in cotyledons during germination prior to other lipoxygenase forms}}, year = {1996}, pages = {288-293}, journal = {Planta}, doi = {10.1007/BF00206255}, url = {http://link.springer.com/journal/425}, volume = {198}, abstract = {Lipid bodies are degraded during germination. Whereas some proteins, e.g. oleosins, are synthesized during the formation of lipid bodies of maturating seeds, a new set of proteins, including a specific form of lipoxygenase (LOX; EC, is detectable in lipid bodies during the stage of fat degradation in seed germination. In cotyledons of cucumber (Cucumis sativus L.) seedlings at day 4 of germination, the most conspicuous staining with anti-LOX antibodies was observed in the cytosol. At very early stages of germination, however, the LOX form present in large amounts and synthesized preferentially was the lipid-body LOX. This was demonstrated by immunocytochemical staining of cotyledons from 1-h and 24-h-old seedlings: the immunodecoration of sections of 24-h-old seedlings with anti-LOX antiserum showed label exclusively correlated with lipid bodies of around 3 μm in diameter. In accordance, the profile of LOX protein isolated from lipid bodies during various stages of germination showed a maximum at day 1. By measuring biosynthesis of the protein in vivo we demonstrated that the highest rates of synthesis of lipid-body LOX occurred at day 1 of germination. The early and selective appearance of a LOX form associated with lipid bodies at this stage of development is discussed.} } @Article{IPB-383, author = {Herde, O. and Atzorn, R. and Fisahn, J. and Wasternack, C. and Willmitzer, L. and Peña-Cortés, H.}, title = {{Localized wounding by heat initiates the accumulation of proteinase inhibitor II in abscisic acid-deficient plants by triggering jasmonic acid biosynthesis}}, year = {1996}, pages = {853-860}, journal = {Plant Physiol.}, volume = {112}, } @Article{IPB-385, author = {Peña-Cortés, H. and Prat, S. and Atzorn, R. and Wasternack, C. and Willmitzer, L.}, title = {{Pin2 gene expression in potato and tomato detached leaves from ABA-deficient potato and tomato plants upon systemin treatment}}, year = {1996}, pages = {447-451}, journal = {Planta}, volume = {198}, } @Article{IPB-386, author = {Wasternack, C. and Atzorn, R. and Pena-Cortes, H. and Parthier, B.}, title = {{Alteration of gene expression by jasmonate and ABA in tobacco and tomato}}, year = {1996}, pages = {503-510}, journal = {J. Plant Physiol.}, volume = {147}, } @Article{IPB-380, author = {Feussner, K. and Guranowski, A. and Kostka, S. and Wasternack, C.}, title = {{Diadenosine 5'5'''-P1,P4-tetraphosphate (Ap4A) hydrolase from tomato (Lycopersicon esculentum cv. Lukullus) - Purification, Biochemical properties and behaviour during stress}}, year = {1996}, pages = {477-486}, journal = {Z. Naturforsch.}, volume = {51c}, } @Article{IPB-335, author = {O'Donnell, P.J. and Calvert, C. and Atzorn, R. and Wasternack, C. and Leyser, H.M.O. and Bowles, D.J.}, title = {{Ethylene as a signal mediating the wound response of tomato plants}}, year = {1996}, pages = {1914-1917}, journal = {Science}, volume = {274}, }