TY - JOUR ID - 10298 TI - Post-embryonic Hourglass Patterns Mark Ontogenetic Transitions in Plant Development JO - Mol. Biol. Evol. PY - 2016 SP - 1158-1163 AU - Drost, H.-G. AU - Bellstädt, J. AU - Ó'Maoiléidigh, D. S. AU - Silva, A. T. AU - Gabel, A. AU - Weinholdt, C. AU - Ryan, P. T. AU - Dekkers, B. J. W. AU - Bentsink, L. AU - Hilhorst, H. W. M. AU - Ligterink, W. AU - Wellmer, F. AU - Grosse, I. AU - Quint, M. AU - VL - 33 UR - DO - 10.1093/molbev/msw039 AB - The historic developmental hourglass concept depicts the convergence of animal embryos to a common form during the phylotypic period. Recently, it has been shown that a transcriptomic hourglass is associated with this morphological pattern, consistent with the idea of underlying selective constraints due to intense molecular interactions during body plan establishment. Although plants do not exhibit a morphological hourglass during embryogenesis, a transcriptomic hourglass has nevertheless been identified in the model plant Arabidopsis thaliana. Here, we investigated whether plant hourglass patterns are also found postembryonically. We found that the two main phase changes during the life cycle of Arabidopsis, from embryonic to vegetative and from vegetative to reproductive development, are associated with transcriptomic hourglass patterns. In contrast, flower development, a process dominated by organ formation, is not. This suggests that plant hourglass patterns are decoupled from organogenesis and body plan establishment. Instead, they may reflect general transitions through organizational checkpoints. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 11365 TI - Coronalon: a powerful tool in plant stress physiology JO - FEBS Lett. PY - 2004 SP - 17-22 AU - Schüler, G. AU - Mithöfer, A. AU - Baldwin, I. T. AU - BERGER, S. AU - Ebel, J. AU - Santos, J. G. AU - Herrmann, G. AU - Hölscher, D. AU - Kramell, R. AU - Kutchan, T. M. AU - Maucher, H. AU - Schneider, B. AU - Stenzel, I. AU - Wasternack, C. AU - Boland, W. AU - VL - 563 UR - DO - 10.1016/S0014-5793(04)00239-X AB - Coronalon, a synthetic 6‐ethyl indanoyl isoleucine conjugate, has been designed as a highly active mimic of octadecanoid phytohormones that are involved in insect and disease resistance. The spectrum of biological activities that is affected by coronalon was investigated in nine different plant systems specifically responding to jasmonates and/or 12‐oxo‐phytodienoic acid. In all bioassays analyzed, coronalon demonstrated a general strong activity at low micromolar concentrations. The results obtained showed the induction of (i) defense‐related secondary metabolite accumulation in both cell cultures and plant tissues, (ii) specific abiotic and biotic stress‐related gene expression, and (iii) root growth retardation. The general activity of coronalon in the induction of plant stress responses together with its simple and efficient synthesis suggests that this compound might serve as a valuable tool in the examination of various aspects in plant stress physiology. Moreover, coronalon might become employed in agriculture to elicit plant resistance against various aggressors. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 11351 TI - Constitutive overexpression of allene oxide cyclase in tomato (Lycopersicon esculentum cv. Lukullus) elevates levels of some jasmonates and octadecanoids in flower organs but not in leaves JO - Phytochemistry PY - 2004 SP - 847-856 AU - Miersch, O. AU - Weichert, H. AU - Stenzel, I. AU - Hause, B. AU - Maucher, H. AU - Feussner, I. AU - Wasternack, C. AU - VL - 65 UR - DO - 10.1016/j.phytochem.2004.01.016 AB - The allene oxide cyclase (AOC), an enzyme in jasmonate biosynthesis, occurs in vascular bundles and ovules of tomato flowers which exhibit a tissue-specific oxylipin signature (Plant J. 24, 113-126, 2000). Constitutive overexpression of the AOC did not led to altered levels of jasmonates in leaves, but these levels increased upon wounding or other stresses suggesting regulation of jasmonate biosynthesis by substrate availability (Plant J. 33, 577-589, 2003). Here, we show dramatic changes in levels of jasmonic acid (JA), of 12-oxo-phytodienoic acid (OPDA), their methyl esters (JAME, OPDAME), and of dinor-OPDA in most flower organs upon constitutive overexpression of AOC. Beside a dominant occurrence of OPDAME and JA in most flower organs, the ratio among the various compounds was altered differentially in the organs of transgenic flowers, e.g. OPDAME increased up to 53-fold in stamen, and JA increased about 51-fold in buds and 7.5-fold in sepals. The increase in jasmonates and octadecanoids was accompanied by decreased levels of free lipid hydro(per)oxy compounds. Except for 16:2, the AOC overexpression led to a significant increase in free but not esterified polyunsaturated fatty acids in all flower organs. The data suggest different regulation of JA biosynthesis in leaves and flowers of tomato.Constitutive overexpression of the AOC increases in all flower organs levels of some jasmonates and octadecanoids, alters the ratios among the compounds, decreases levels of free lipid hydro(per)oxy compounds and increases levels of free but not of esterified polyunsaturated fatty acids. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 11349 TI - The allene oxide cyclase of barley (Hordeum vulgare L.)—cloning and organ-specific expression JO - Phytochemistry PY - 2004 SP - 801-811 AU - Maucher, H. AU - Stenzel, I. AU - Miersch, O. AU - Stein, N. AU - Prasad, M. AU - Zierold, U. AU - Schweizer, P. AU - Dorer, C. AU - Hause, B. AU - Wasternack, C. AU - VL - 65 UR - DO - 10.1016/j.phytochem.2004.01.009 AB - 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. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 11342 TI - Phloem-specific expression of the wound-inducible ribonuclease LE from tomato (Lycopersicon esculentum cv. Lukullus) JO - Planta PY - 2004 SP - 233-242 AU - Köck, M. AU - Groß, N. AU - Stenzel, I. AU - Hause, G. AU - VL - 219 UR - DO - 10.1007/s00425-004-1227-4 AB - Ribonuclease LE (RNaseLE) from tomato (Lycopersicon esculentum Mill. cv. Lukullus) belongs to the widespread RNase T2 family of ribonucleases. With the exception of S-RNases of the solanaceous self-incompatibility system the functions of other members of the RNase T2 family are only barely understood. Using a 2.6-kbp putative promoter sequence of RNaseLE in front of the uidA reporter gene, expression of β-glucuronidase in developing phloem tissue and, especially, in the meristematic and elongation zones at root tips was detected. The tissue-specific expression accords with the range of cis-acting elements detected in the RNaseLE promoter. RNaseLE mRNA was localized in developing phloem cells but not in mature phloem tissue, suggesting association of RNaseLE expression with phloem development. Histochemical staining of β-glucuronidase activity as well as detailed inspection of RNaseLE at mRNA, protein and enzyme activity levels revealed that the wound-induced expression of RNaseLE was also restricted to vascular tissue. RNaseLE transcript accumulation detected by in situ hybridization occurred preferentially in phloem and cambial cells of stem sections upon wounding. The data provide evidence for a role of RNaseLE in a tissue-specific wound response and in wound healing of tomato. A2 - C1 - 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 - CHAP ID - 9689 TI - The Lipoxygenase Pathway in Mycorrhizal Roots of Medicago Truncatula T2 - Advanced Research on Plant Lipids PB - PY - 2003 SP - 287-290 AU - Stumpe, M. AU - Stenzel, I. AU - Weichert, H. AU - Hause, B. AU - Feussner, I. AU - VL - UR - DO - 10.1007/978-94-017-0159-4_67 AB - Mycorrhizas are by far the most frequent occurring beneficial symbiotic interactions between plants and fungi. Species in >80% of extant plant families are capable of establishing an arbuscular mycorrhiza (AM). In relation to the development of the symbiosis the first molecular modifications are those associated with plant defense responses, which seem to be locally suppressed to levels compatible with symbiotic interaction (Gianinazzi-Pearson, 1996). AM symbiosis can, however, reduce root disease caused by several soil-borne pathogens. The mechanisms underlying this protective effect are still not well understood. In plants, products of the enzyme lipoxygenase (LOX) and the corresponding downstream enzymes, collectively named LOX pathway (Fig. 1B), are involved in wound healing, pest resistance, and signaling, or they have antimicrobial and antifungal activity (Feussner and Wasternack, 2002). The central reaction in this pathway is catalyzed by LOXs leading to formation of either 9- or 13-hydroperoxy octadeca(di/trien)oic acids (9/13-HPO(D/T); Brash, 1999). Thus LOXs may be divided into 9- and 13-LOXs (Fig. 1A). Seven different reaction branches within this pathway can use these hydroperoxy polyenoic fatty acids (PUFAs) leading to (i) keto PUFAs by a LOX; (ii) epoxy hydroxy-fatty acids by an epoxy alcohol synthase (EAS); (iii) octadecanoids and jasmonates via allene oxide synthase (AOS); (iv) leaf aldehydes and leaf alcohols via fatty acid hydroperoxide lyase (HPL); (v) hydroxy PUFAs (reductase); (vi) divinyl ether PUFAs via divinyl ether synthase (DES); and (vii) epoxy- or dihydrodiolPUFAs via peroxygenase (PDX; Feussner and Wasternack, 2002). AOS, HPL and DES belong to one subfamily of P450-containing enzymes, the CYP74 family (Feussner and Wasternack, 2002). Here, the involvement of this CYP74 enzyme family in mycorrhizal roots of M. truncatula during early stages of AM symbiosis formation was analyzed. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - CHAP ID - 9687 TI - Transcriptional Activation of Jasmonate Biosynthesis Enzymes is not Reflected at Protein Level T2 - Advanced Research on Plant Lipids PB - PY - 2003 SP - 267-270 AU - Stenzel, I. AU - Hause, B. AU - Feussner, I. AU - Wasternack, C. AU - VL - UR - DO - 10.1007/978-94-017-0159-4_62 AB - Jasmonic acid (JA) and its precursor 12-oxo phytodienoic acid (OPDA) are lipid-derived signals in plant stress responses and development (Wasternack and Hause, 2002). Within the wound-response pathway of tomato, a local response of expression of defense genes such as the proteinase inhibitor 2 gene (PIN2) is preceded by a rise in JA (Herde et al., 1996; Howe et al., 1996) and ethylene (O’Donnell et al., 1996). Mutants affected in JA biosynthesis such as defl (Howe et al., 1996) or spr-2 (Li et al., 2002) clearly indicated that JA biosynthesis is an ultimate part of wound signaling. It is less understood, however, how the rise in JA is regulated. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 11438 TI - Jasmonate biosynthesis and the allene oxide cyclase family of Arabidopsis thaliana JO - Plant Mol. Biol. PY - 2003 SP - 895-911 AU - Stenzel, I. AU - Hause, B. AU - Miersch, O. AU - Kurz, T. AU - Maucher, H. AU - Weichert, H. AU - Ziegler, J. AU - Feussner, I. AU - Wasternack, C. AU - VL - 51 UR - DO - 10.1023/A:1023049319723 AB - In biosynthesis of octadecanoids and jasmonate (JA), the naturally occurring enantiomer is established in a step catalysed by the gene cloned recently from tomato as a single-copy gene (Ziegler et al., 2000). Based on sequence homology, four full-length cDNAs were isolated from Arabidopsis thaliana ecotype Columbia coding for proteins with AOC activity. The expression of AOCgenes was transiently and differentially up-regulated upon wounding both locally and systemically and was induced by JA treatment. In contrast, AOC protein appeared at constitutively high basal levels and was slightly increased by the treatments. Immunohistochemical analyses revealed abundant occurrence of AOC protein as well as of the preceding enzymes in octadecanoid biosynthesis, lipoxygenase (LOX) and allene oxide synthase (AOS), in fully developed tissues, but much less so in 7-day old leaf tissues. Metabolic profiling data of free and esterified polyunsaturated fatty acids and lipid peroxidation products including JA and octadecanoids in wild-type leaves and the jasmonate-deficient mutant OPDA reductase 3 (opr3) revealed preferential activity of the AOS branch within the LOX pathway. 13-LOX products occurred predominantly as esterified derivatives, and all 13-hydroperoxy derivatives were below the detection limits. There was a constitutive high level of free 12-oxo-phytodienoic acid (OPDA) in untreated wild-type and opr3 leaves, but an undetectable expression of AOC. Upon wounding opr3 leaves exhibited only low expression of AOC, wounded wild-type leaves, however, accumulated JA and AOC mRNA. These and further data suggest regulation of JA biosynthesis by OPDA compartmentalization and a positive feedback by JA during leaf development. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 11437 TI - Differential expression of the LePS2 phosphatase gene family in response to phosphate availability, pathogen infection and during development JO - Physiol. Plant. PY - 2003 SP - 138-146 AU - Stenzel, I. AU - Ziethe, K. AU - Schurath, J. AU - Hertel, S. C. AU - Bosse, D. AU - Köck, M. AU - VL - 118 UR - DO - 10.1034/j.1399-3054.2003.00091.x AB - In this study, we report the cloning of the three‐member LePS2 gene family of acid phosphatases via subtractive screening of a cDNA library of Pi‐starved cultivated tomato cells (Lycopersicon esculentum Mill. cv. Lukullus). As members of the plant Pi‐starvation response, LePS2 genes were tightly regulated in cultivated cells and tomato seedlings by Pi availability. The LePS2 enzymes which are most likely expressed in the cytoplasma could be involved in processes that are accompanied by degradation of phosphorylated organic substrates. Independently from exogenous phosphate supply LePS2 expression was detected in tomato endosperm during germination. LePS2 genes were differentially induced after infection with the bacterial pathogen Pseudomonas syringae and in the early stages of flower development. Using RT–PCR it was found that the gene LePS2B was the most abundant transcript in phosphate‐depleted cells, but a reduced expression was determined in floral buds and it was not found during pathogen interaction. In this respect, it is interesting that the promoter sequences of the LePS2 genes are also divergent. LePS2 gene products may have functions in developmental processes which are restricted to distinct plant tissues or cell types. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 11436 TI - Allene oxide cyclase dependence of the wound response and vascular bundle-specific generation of jasmonates in tomato - amplification in wound signalling JO - Plant J. PY - 2003 SP - 577-589 AU - Stenzel, I. AU - Hause, B. AU - Maucher, H. AU - Pitzschke, A. AU - Miersch, O. AU - Ziegler, J. AU - Ryan, C. A. AU - Wasternack, C. AU - VL - 33 UR - DO - 10.1046/j.1365-313X.2003.01647.x AB - The allene oxide cyclase (AOC)‐catalyzed step in jasmonate (JA) biosynthesis is important in the wound response of tomato. As shown by treatments with systemin and its inactive analog, and by analysis of 35S::prosysteminsense and 35S::prosysteminantisense plants, the AOC seems to be activated by systemin (and JA) leading to elevated formation of JA. Data are presented on the local wound response following activation of AOC and generation of JA, both in vascular bundles. The tissue‐specific occurrence of AOC protein and generation of JA is kept upon wounding or other stresses, but is compromised in 35S::AOCsense plants, whereas 35S::AOCantisense plants exhibited residual AOC expression, a less than 10% rise in JA, and no detectable expression of wound response genes. The (i) activation of systemin‐dependent AOC and JA biosynthesis occurring only upon substrate generation, (ii) the tissue‐specific occurrence of AOC in vascular bundles, where the prosystemin gene is expressed, and (iii) the tissue‐specific generation of JA suggest an amplification in the wound response of tomato leaves allowing local and rapid defense responses. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER - TY - JOUR ID - 11403 TI - Occurrence of the allene oxide cyclase in different organs and tissues of Arabidopsis thaliana JO - Phytochemistry PY - 2003 SP - 971-980 AU - Hause, B. AU - Stenzel, I. AU - Miersch, O. AU - Wasternack, C. AU - VL - 64 UR - DO - 10.1016/S0031-9422(03)00447-3 AB - Occurrence of an essential enzyme in jasmonate (JA) biosynthesis, the allene oxide cyclase, (AOC) was analyzed in different developmental stages and various organs of Arabidopsis thaliana plants by immuno blot analysis and immunocytological approaches. Levels of AOC and of the two preceding enzymes in JA biosynthesis increased during seedling development accompanied by increased levels of JA and 12-oxophytodienoic acid levels after 4 and 8 weeks. Most tissues including all vascular bundles and that of flower buds contain AOC protein. Flowers shortly before opening, however, contain AOC protein preferentially in ovules, stigma cells and vascular bundles, whereas in anthers and pollen AOC could not be detected. The putative roles of AOC and JA in development are discussed.The allene oxide cyclase (AOC) is an important enzyme in jasmonate biosynthesis. Levels and occurrence of AOC in different organs and tissues are altered during development of Arabidopsis thaliana. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER -