methyl-jasmonate and benzylaminopurine

Light is an important physical factor necessary for the growth, morphogenesis and production of bioactive compounds in plants. In this study, effects of different photoperiod regimes and hormonal elicitors were investigated on the accumulation of biomass, antioxidant potential and biosynthesis of secondary volatiles in the cell cultures of Ajuga bracteosa. Maximum accumulation of biomass (13.2 g/L) was recorded in cell cultures established at 1.0 mg/L benzylaminopurine (BA) in exposure to continuous dark. Biochemical assays showed that in the presence of 0.5 methyl jasmonate (Me-J), cell cultures grown under continuous dark had the higher activities of superoxide dismutase (SOD: 4.5 U/mg), peroxidase (POD: 3.1 U/mg), total phenolic content (TPC: 8.1 mg GAE/g of DW) and total flavonoid content (TFC: 5.2 mg QE/g of DW) respectively. Nonetheless, the free radical scavenging activity (FRSA) was found correlated with the phenyl ammonia lyase (PAL) activity in the dark grown cell cultures. Analysis through gas chromatography-mass spectrometry (GC-MS) showed, biosynthesis of 29 compounds in the in vitro raised cell cultures. The major identified compounds consisted of monoterpene hydrocarbons such as β-pinene (2.1-9.5%), β-ocimene (1.4-8.3%), 1-terpinene-4-ol (5.8-9.6%), caryophyllene (1.3-6.2%), β-farnesene (0.82-7.8), oxygenated monoterpenes including myrtenal (2.2-8.4%), citronellyl acetate (2.1-7.3%) and sesquiterpenes such as caryophyllene oxide (1.5-5.5) and β-elemene (2.2-8.8%). This protocol has the potential for commercial production of important secondary volatiles.

Topics: Acetates; Ajuga; Benzyl Compounds; Biomass; Cyclopentanes; Flavonoids; Gas Chromatography-Mass Spectrometry; Oxylipins; Peroxidase; Phenols; Phenylalanine Ammonia-Lyase; Photoperiod; Plant Cells; Purines; Superoxide Dismutase

Eryngium planum L. has been reported as a medicinal plant used in traditional medicine in Europe. The tissue cultures may be an alternative source of the biomass rich in desired bioactive compounds. The purpose of this study was to investigate the influence of the biotechnological techniques on the selected phenolic acids accumulation in the agitated shoot cultures of E. planum. Qualitative and quantitative analyses of those compounds in 50% aqueous - methanolic extracts from the biomass were conducted by applying the HPLC method. Methyl jasmonate (MeJA), yeast extract (YE) and sucrose (Suc) stimulated accumulation of the phenolic acids: rosmarinic (RA), chlorogenic (CGA) and caffeic (CA) in in vitro shoot cultures. Cultivation of shoots in liquid MS media supplemented with 1.0 mg L(-1) 6-benzyladenine and 0.1 mg L(-1) indole-3-acetic acid in the presence of 100 µM MeJA for 48h was an optimum condition of elicitation and resulted in approximately 4.5-fold increased content of RA + CGA + CA in plant material compared to the control (19.795 mg g(-1) DW, 4.36 mg g(-1) DW, respectively). The results provide the first evidence that the selected phenolic acids can be synthesized in elicited shoot cultures of flat sea holly in higher amount than in untreated shoots.

Topics: Acetates; Benzyl Compounds; Biomass; Biotechnology; Caffeic Acids; Cell Culture Techniques; Chlorogenic Acid; Cinnamates; Culture Media; Cyclopentanes; Depsides; Eryngium; Indoleacetic Acids; Kinetin; Oxylipins; Plant Shoots; Plants, Medicinal; Purines; Rosmarinic Acid; Sucrose; Yeasts

Senescence is a phase of leaf ontogeny marked by declining photosynthetic activity that is paralleled by a decline in chloroplast function. The photosystem II in a plant is considered to be the primary site where delayed fluorescence (DF) is produced. We report here a simple, rapid, and non-invasive technique for detecting plants senescence based on quantitative measurements of DF. In the experimental study, various senescence symptoms induced by age or hormones were examined in the Catharanthus roseus L. G. Don plants. Detecting the DF emissions from leaves with a home-made DF biosensor enables DF parameters of C. roseus to be produced in a short time. Meanwhile, evaluations of leaves senescence were made from measurements of chlorophyll content, ion leakage, and net photosynthesis rate (Pn) based on the consumption of CO2 in the tested plants. The results of our investigation demonstrate that the changes in DF intensity of green plants can truly reflect the changes in photosynthetic capacity and chlorophyll content during age-dependent and hormone-modulated senescence. Moreover, the DF intensity negatively correlates with ion leakage in both types of senescence. With proper calibration, DF may provide an important approach for monitoring senescence process in vivo and quantitatively evaluating senescence extent. Therefore, a DF technique could be potentially useful for less time-consuming and automated screening of the interesting mutants with genetic modifications that change the plant senescence progress.

Topics: Acetates; Benzyl Compounds; Catharanthus; Cellular Senescence; Chlorophyll; Cyclopentanes; Fluorescence; Kinetin; Oxylipins; Photosynthesis; Photosystem II Protein Complex; Plant Growth Regulators; Plant Leaves; Purines; Spectrometry, Fluorescence

Camptothecin derivatives are clinically used anti-tumor compounds that biogenetically belong to a group of monoterpenoid indole alkaloids (TIA). We have already established a hairy root culture of Ophiorrhiza pumila (Rubiaceae) that produces camptothecin. The present study describes the cloning and characterization of cDNAs encoding strictosidine synthase (OpSTR; EC 4.3.3.2) and tryptophan decarboxylase (OpTDC; EC 4.1.1.28), two key enzymes in the biosynthesis of TIA from hairy roots of O. pumila. We also isolated the cDNA coding for NADPH:cytochrome P450 reductase (OpCPR; EC 1.6.2.4) that is presumed to be indirectly involved in camptothecin synthesis. The recombinant OpSTR and OpTDC proteins exhibit STR and TDC activities, respectively, when expressed in Escherichia coli. The tissue-specific and stress-inducible expression patterns of OpSTR and OpTDC were quite similar, unlike those of OpCPR. The high expression of OpSTR and OpTDC observed in hairy roots, roots and stems were closely correlated with STR protein accumulation as observed by immunoblot analysis. Plant stress compounds like salicylic acid repressed expression of OpSTR and OpTDC, suggesting coordinate regulation of these genes for camptothecin biosynthesis.

Topics: Acetates; Adenine; Aromatic-L-Amino-Acid Decarboxylases; Base Sequence; Benzyl Compounds; Camptothecin; Carbon-Nitrogen Lyases; Cloning, Molecular; Cyclopentanes; DNA, Complementary; Escherichia coli; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Kinetin; Molecular Sequence Data; NADPH-Ferrihemoprotein Reductase; Naphthaleneacetic Acids; Oxylipins; Phylogeny; Plant Roots; Purines; Rubiaceae; Salicylic Acid; Sequence Analysis, DNA

A screen for Arabidopsis mutants that were insensitive to methyl jasmonate (MeJA) in an assay for seedling root growth yielded only alleles of previously isolated mutants jar1 and coi1, with one exception. Mapping of the locus and morphological characterization of the new mutant suggested it might be allelic to axr1, which had not previously been reported to show resistance to MeJA. The F(1) from a cross of the new mutant with axr1-3 did not show complementation, confirming that these are the same genes. The new allele is called axr1-24. In addition to MeJA and indole-3-acetic acid (IAA), axr1-24 had decreased sensitivity to 1-aminocyclopropane-1-carboxylic acid, 6-benzylamino-purine, epi-brassinolide, and abscisic acid. Both axr1-24 and the previously characterized axr1-3 allele were shown to be susceptible to the opportunistic pathogen Pythium irregulare, a trait found in other jasmonate response mutants, including jar1-1. The double mutant jar1-1/axr1-3 was more resistant to inhibition of root growth by MeJA and was more susceptible to P. irregulare infection than either single mutant, suggesting these genes might act in independent response pathways. In contrast, resistance to IAA in the double mutant was not different from axr1-3. Northern-blot analysis showed that IAA induced the jasmonate-responsive lipoxygenase 2, AOS, and AtVSP gene transcripts and induction was strongly impaired in axr1-3. However, transcript induction by MeJA was only minimally affected in axr1-3. This study demonstrates that in addition to auxin signaling, the AXR1 locus is involved in MeJA response, providing a mechanistic link between jasmonate and auxin-signaling pathways.

Topics: Abscisic Acid; Acetates; Adenine; Alleles; Amino Acids, Cyclic; Arabidopsis; Arabidopsis Proteins; Benzyl Compounds; Brassinosteroids; Cholestanols; Cyclopentanes; Gene Expression Regulation, Plant; Genetic Complementation Test; Germination; Growth Substances; Indoleacetic Acids; Kinetin; Mutation; Nucleotidyltransferases; Oxylipins; Plant Growth Regulators; Plant Roots; Purines; Pythium; Seeds; Signal Transduction; Steroids, Heterocyclic