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Publikation

Wasternack, C.; Introductory Remarks on Biosynthesis and Diversity in Actions J. Plant Growth Regul. 23, 167-169, (2004) DOI: 10.1007/s00344-004-0051-1

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Publikation

Maucher, H.; Stenzel, I.; Miersch, O.; Stein, N.; Prasad, M.; Zierold, U.; Schweizer, P.; Dorer, C.; Hause, B.; Wasternack, C.; The allene oxide cyclase of barley (Hordeum vulgare L.)—cloning and organ-specific expression Phytochemistry 65, 801-811, (2004) DOI: 10.1016/j.phytochem.2004.01.009

The naturally occurring enantiomer of the various octadecanoids and jasmonates is established in a biosynthetic step catalyzed by the allene oxide cyclase (AOC). The AOC converts an allene oxide formed by an allene oxide synthase (AOS). Here, we show cloning and characterization of cDNAs encoding the AOC and a third AOS, respectively, in addition to the two AOSs previously published (Plant J. 21, 199–213, 2000). The ORF of the AOC-cDNA of 717 bp codes for a protein of 238 amino acid residues carrying a putative chloroplast target sequence. Overexpression without chloroplast target sequence revealed AOC activity. The AOC was found to be a single copy gene which mapped on chromosome 6H. AOC mRNA accumulation appeared in leaf segments upon treatment with various jasmonates, octadecanoids and ABA or during stress such as treatment with sorbitol or glucose solutions. Infection with powdery mildew activated AOC expression in susceptible and resistant lines of barley which correlated with PR1b expression. Among different tissues of barley seedlings, the scutellar node and leaf base accumulated AOC mRNA preferentially which correlated with accumulation of mRNAs for other biosynthetic enzymes (lipoxygenases, AOSs). AOC mRNA accumulation appeared also abundantly in parts of the root containing the tip and correlated with elevated levels of jasmonates. The data suggest a link of AOC expression and JA formation and support role of JA in stress responses and development of barley.Barley plants contain one allene oxide cyclase and three allene oxide synthases which are up-regulated during seedling development accompanied by elevated levels of jasmonate.
Publikation

Groß, N.; Wasternack, C.; Köck, M.; Wound-induced RNaseLE expression is jasmonate and systemin independent and occurs only locally in tomato (Lycopersicon esculentum cv. Lukullus) Phytochemistry 65, 1343-1350, (2004) DOI: 10.1016/j.phytochem.2004.04.036

Tomato RNaseLE is induced by phosphate deficiency and wounding and may play a role in macromolecular recycling as well as wound healing. Here, we analyzed the role of jasmonate and systemin in the wound-induced RNaseLE activation. The rapid expression of RNaseLE upon wounding of leaves leading to maximal RNase activity within 10 h, appeared only locally. Jasmonic acid (JA) or its molecular mimic ethyl indanoyl isoleucine conjugate did not induce RNaseLE expression. Correspondingly, RNaseLE was expressed upon wounding of 35S::allene oxide cyclase antisense plants known to be JA deficient. RNaseLE was not expressed upon systemin treatment, but was locally expressed in the spr1 mutant which is affected in systemin perception. In tomato plants carrying a PromLE::uidA construct, GUS activity could be detected upon wounding, but not following treatment with JA or systemin. The data indicate a locally acting wound-inducible systemin- and JA-independent signaling pathway for RNaseLE expression.RNaseLE expression was analyzed by pharmacological studies of different tomato lines and upon wounding of leaves. The gene is only locally activated via a new type of wound-induced signaling pathway in a jasmonate/systemin-independent manner.
Bücher und Buchkapitel

Wasternack, C.; Jasmonates—Biosynthesis and Role in Stress Responses and Developmental Processes 143-155, (2004) DOI: 10.1016/B978-012520915-1/50012-6

This chapter presents jasmonates and their related compounds and discusses jasmonate-induced alteration of gene expression. Jasmonates exerts two different changes in gene expression— decrease in the expression of nuclear- and chloroplast-encoded genes and increase in the expression of specific genes. Jasmonates are shown to alter sink-source relationships such as JA promotes formation of the N-rich vegetative storage proteins—VSPα and VSPβ—of soybean, including reallocation in pod filling. In addition to such nutrient reallocation to other parts of the plant, jasmonates cause decreases in photosynthesis and chlorophyll content, the most significant manifestations of senescence in leaves. The rise of endogenous jasmonates upon stress or exogenous treatment with jasmonates correlates in time with the expression of various genes. The promotion of senescence by jasmonates is counteracted by cytokinins. The capacity of jasmonates to down regulate photosynthetic genes may also be one determinant in the onset of senescence.
Publikation

Leopold, J.; Hause, B.; Lehmann, J.; Graner, A.; Parthier, B.; Wasternack, C.; Isolation, characterization and expression of a cDNA coding for a jasmonate-inducible protein of 37 kDa in barley leaves Plant Cell Environ. 19, 675-684, (1996) DOI: 10.1111/j.1365-3040.1996.tb00402.x

In barley leaves, there is a dramatic alteration of gene expression upon treatment with jasmonates leading to the accumulation of newly formed proteins, designated as jasmonate‐inducible proteins (JIPs). In the present study, a new jasmonate‐inducible cDNA, designated pHvJS37, has been isolated by differential screening of a γgt10 cDNA library constructed from mRNA of jasmonate‐treated barley leaf segments. The open reading frame (ORF) encodes a 39‐9 kDa polypeptide which cross‐reacts with antibodies raised against the in vivo JIP‐37. The hydropathic plot suggests that the protein is mainly hydrophilic, containing two hydrophilic domains near the C‐terminus. Database searches did not show any sequence homology of pHv.JS37 to known sequences. Southern analysis revealed at least two genes coding for JIP‐37 which map to the distal portion of the long arm of chromosome 3 and are closely related to genes coding for JIP‐23. The expression pattern of the JIP‐37 genes over time shows differential responses to jasmonate, abscisic acid (ABA), osmotic stress (such as sorbitol treatment) and desiccation stress. No expression was found under salt stress. From experiments using an inhibitor and intermediates of jasmonate synthesis such as α‐linolenic acid and 12‐oxophytodienoic acid, we hypothesize that there is a stress‐induced lipid‐based signalling pathway in which an endogenous rise of jasmonate switches on JIP‐37 gene expression. Using immunocytochemical techniques, JIP‐37 was found to be simultaneously located in the nucleus, the cytoplasm and the vacuoles.
Publikation

Herde, O.; Atzorn, R.; Fisahn, J.; Wasternack, C.; Willmitzer, L.; Pena-Cortes, H.; Localized Wounding by Heat Initiates the Accumulation of Proteinase Inhibitor II in Abscisic Acid-Deficient Plants by Triggering Jasmonic Acid Biosynthesis Plant Physiol. 112, 853-860, (1996) DOI: 10.1104/pp.112.2.853

To test whether the response to electrical current and heat treatment is due to the same signaling pathway that mediates mechanical wounding, we analyzed the effect of electric-current application and localized burning on proteinase inhibitor II (Pin2) gene expression in both wild-type and abscisic acid (ABA)-deficient tomato (Lycopersicon esculentum Mill.) and potato (Solanum phureja) plants. Electric-current application and localized burning led to the accumulation of Pin2 mRNA in potato and tomato wild-type plants. Among the treatments tested, only localized burning of the leaves led to an accumulation of Pin2 mRNA in the ABA-deficient plants. Electric-current application, like mechanical injury, was able to initiate ABA and jasmonic acid (JA) accumulation in wild-type but not in ABA-deficient plants. In contrast, heat treatment led to an accumulation of JA in both wild-type and ABA-deficient plants. Inhibition of JA biosynthesis by aspirin blocked the heat-induced Pin2 gene expression in tomato wild-type leaves. These results suggest that electric current, similar to mechanical wounding, requires the presence of ABA to induce Pin2 gene expression. Conversely, burning of the leaves activates Pin2 gene expression by directly triggering the biosynthesis of JA by an alternative pathway that is independent of endogenous ABA levels.
Publikation

Feussner, I.; Hause, B.; Nellen, A.; Wasternack, C.; Kindl, H.; Lipid-body lipoxygenase is expressed in cotyledons during germination prior to other lipoxygenase forms Planta 198, 288-293, (1996) DOI: 10.1007/BF00206255

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 1.13.11.12), 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.
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