Cell cultures, parsley

In addition to the proteins mentioned above, there have been many reports of the induction of pathogenesis-related proteins (PRPs) in a number of plant species infected by viruses, viroids, bacteria or fungi (Van Loon, 1985). It has been shown that in cultured parsley cells, increased transcription of two PRP genes occurs within a few minutes of exposure to fungal elicitors (Somssich et al., 1986). Although several PRPs from tobacco have been purified and their cDNAs isolated (Hooft van Huijsduij-nen. Van Loon Bol, 1986), the exact action of these proteins remains unclear. 

Chappell, J., Hahlbrock, K. Boiler, T. (1984). Rapid induction of ethylene biosynthesis in cultured parsley cells by fungal elicitor and its relationship to the induction of phenylalanine ammonia-lyase. Planta, 161, 475-80. 

The first nucleotide sequence for CHS was determined from cultured parsley cells [53]. Since then, its expression and regulation have been extensively studied in numerous plant systems in relation to a myriad of different conditions and stimuli [e.g., 21 and ref therein]. Due to its key role in flavonoid biosynthesis, CHS has been a popular target for various gene-silencing techniques in attempts to generate flavonoid-deficient plants [16, 54 and ref therein]. 

Flavanone 3 -hydroxylase (F3 H ECl.14.13.21 CYP75B) activity was initially identified in microsomal preparations of golden weed (Haplopappus gracilis) [110]. E3 H from irradiated parsley cell cultures was later biochemically analyzed and characterized as a cytochrome P450 having an absolute requirement for NADPH and molecular oxygen as cofactors [111]. The enzyme has been shown to have activity with flavanones, flavones, dihydroflavonols, and flavonols, but does not appear to have activity with anthocyanidins [111]. The first cDNA clone for E3 H was isolated from Petunia [112]. It has been suggested that E3 H may serve as an anchor for the proposed flavonoid multi-enzyme complex on the cytosolic surface of the endoplasmic reticulum [44]. 

Britsch L, Heller W, Grisebach. H (1981) Conversion of flavanone to flavone, dihy-droflavonol and flavonol with an enzyme system from cell cultures of parsley. Z Naturforsch... 

HagmannML, HeUerW, GrisebachH (1983) Induction and characterization of a microsomal flavonoid 3 -hydroxylase from parsley cell cultures. Eur J Biochem 134(3) 547-554... 

To what extent is the response of cytosolic and plastidic isozymes of the shikimate pathway coordinated or coupled with one another and to alterations in expression of enzymes of the flavonoid and phenylpropanoid-pathway segments Some of the emerging information is given in Figure 6. Thus, light induction, well known to induce PAL and enzymes of the flavonoid pathway, also induces both DS-Mn and DS-Co in parsley cell cultures (49). However, only the cytosolic CM-2 (and not the plastidic CM-1) was induced. Fungal elicitor was reported to induce only DS-Mn—not DS-Co or either of the chorismate mutase isozymes (49). Previous studies... 

Henstrand JM. 1992. Light and fungal elicitor induce 3-deoxy-D-arabino-heptulonosate 7-phosphate synthase mRNA in suspension cultured cells of parsley (Petroselinum crispum L.). Plant Physiol 98 761-763. 

Co-mediation of oligosaccharides and MJ has been demonstrated in the rice system in the induction of phytoalexins [100]. Exogenously applied MJ to elicited cells increased production of momilactone A to levels higher than those elicited with AT-acetylchitoheptaose alone. In suspension-cultured cells of parsley the influence of MJ on elicitation using cell walls of Phytophtora megasperma (Pmg elicitor) and chitosan was demonstrated [101]. These results suggested MJ conditioned the parsley suspension cells in a time-dependent manner to become more responsive to elicitation. 

This enzyme was first reported in the microsomal fractions of Haplopappus gracilis cell cultures,33 studied in more detail in parsley,34 and later shown to occur in the flowers of several species.7 F3 H catalyzes the hydroxylation of naringenin and dihydrokaempferol (DHK), as well as of apigenin or kaempferol to their respective 3 -hydroxy derivatives, eriodictyol, dihydroquercetin (DHQ), luteolin, and quercetin, but does not accept the flavan 3,4-diols or anthocyanidins as substrates,34 indicating that B-ring hydroxylation of the latter is determined at the dihydroflavonol level. It was more than two decades later that the first cDNA clone encoding F3 H was isolated and characterized from the flowers of Petunia hybridal Arabidopsis thaliana,36 and Perilla frutescens.37 Their recombinant proteins were shown to... 

This enzyme catalyzes the stereospecific conversion of the (2R, JR)-dihydroflavonols, DHK and DHQ, to the corresponding flavonols, by introducing a double bond between C-2 and C-3. The enzyme was first reported in parsley cell cultures,58 and later shown to occur in several plant species.7 A cDNA clone encoding FLS was isolated from Petunia hybridal and its antisense expression strongly reduced flavonol synthesis in flower petals, thus allowing a higher flux of dihydroflavonols to be channeled towards anthocyanin synthesis.59... 

Contents P.LKing Plant Tissue Culture and the Cell Cycle. - KHahlbrock, J. Schroder, J. Vieregge Enzyme Regulation in Parsley and Soybean Cell Cultures. - P. J. Wang,... 

Priming has been observed in various pathosystems as an integral part of both SAR and ISR as well as in chemically induced resistance [69]. Early reports on priming were purely descriptive. The response of the plants was accelerated and they proved also to be more resistant [70,71,72,73]. In parsley cell cultures low doses of the SAR inducers SA,... 

Haulfe, K.D., Hahlbrock, K. and Scheel, D. (1986) Elicitor-stimulated furanocoumarin biosynthesis in cultured parsley cells S-adenosyl-L-methionine bergaptol and S-adenosyl-L-methionine xanthotoxol O-methyltransferases. Z. Naturforsch., 41c, 228-39. 

Lozoya, E., Block, A., Lois, R., Hahlbrock, K. and Scheel, D. (1991) Transcriptional repression of light-induced flavonoid synthesis by elicitor treatment of cultured parsley cells. Plant., 1, 227-34. 

Tietjen, K.G., Hunkier, D. and Matem, U. (1983) Differential response of cultured parsley cells to elicitors from two non-pathogenic strains of fungi. Identification of induced products as coumarin derivatives. Eur.. Biochem., 131, 401-7. 

Tietjen, K. G. Hunkier, D. Matem, U. "Differential Response of Cultured Parsley Cells to Elicitors from Two Non-pathogenic Strains of Fungi, 1. Identification of Induced Products as Coumarin Derivatives" Eur. ]. Biochem. 1983,131, pp 401-407. Devereux, N. Hoare, M. Duimill, P. "Membrane Separation of Protein Precipitates Unstirred Batch Studies" Biotech, and Bioeng. 1986, 28, pp 88-96. Mateus, M. Cabral, J. M. S. "Recovery of 6-a-methylprednisolone from biotransformation medium by tangential flow filtration" In Bioprocess Engineering. 1989, Springer Verlag, (in press). 

Pep Phytophthora soja 13-Amino acid peptide from 42 kDa glycoprotein 19 kDa plasma membrane-bound protein with high binding affinity in parsley cell cultures 38... 

Hahlbrock, K., C. Lamb, C. Purwin, J. Ebel, E. Fautz, and E. Schafer, Rapid response of suspension-cultured parsley cells to the elicitor from Phytophthora megasperma var. sojae. Plant Physiol., 78, 768-773 (1981). 

Many aspects of the biosynthesis of flavonoids have been elucidated, but major progress in sorting out certain reaction steps and the enzymes involved in flavonoid biosynthesis was not possible before tissue and cell culture of suitable plants were developed (Hutchinson, 1986). The use of flowers as sources of enzymes has provided the means for producing " C-labeled substrates (Heller and Forkmann, 1988). Cell cultures of Petroselinum hortense (parsley, Apiaceae) contain both flavone and flavonol glycosides most of the approximately 13 enzymes that catalyze the formation of flavonoid glycosides have been isolated and studied. Light... 

As described above, the first enzyme general to all flavonoid biosynthesis, chalcone synthase (naringenin-chalcone synthase), catalyzes the cyclization of a precursor formed from p-coumaryl-CoA and three units of malonyl-CoA (Fig. 11.6) (Dewick, 1989 Gerats and Martin, 1992 Heller and Forkmann, 1988). The enzyme, usually found in plant epidermal cells, has a molecular weight of about 42,000, requires no cofactors, and has been isolated from several plant cell cultures such as French bean Phaseolus vulgaris), parsley Petroselinum crispum), and the flowers of the carnation (Dianthus caryophyllus, Caryophyllaceae) (Hutchinson, 1986). p-Coumaiic acid and malonyl-CoA are the preferred precursors. Malonyl-ACP will not serve. 

Chalcone synthase from parsley culture cells has a molecular weight of about 77,000 and is composed of two identical subunits of about 42,000 MW. The cDNA complementary to the mRNA of chalcone synthase from irradiated parsley cell cultures has been cloned in Escherichia coli (Grisebach, 1985),... 

Davis, K. R. and K. Hahlbrock, Induction of defense responses in cultured parsley cells by plant cell wall fragments. Plant Physiol., 85, 1286-1290 (1987). 

Figure 6.4. Biosynthesis of apiin in cell cultures of parsley Petroselimm hortense) ...

---