| molecular cloning and characterization of o-methyltransferases from the flower buds of iris hollandica. | in plants, o-methyltransferases (omts) play an important role in methylation of secondary metabolites, especially flavonoids and other phenylpropanoids, and two cdna clones, ihomt1 and ihomt2 (iris hollandica omt), encoding omts were successfully isolated from a cdna library of flower buds of i. hollandica. ihomt1 encodes an open reading frame (orf) of 365 amino acids with calculated molecular mass of 40,193da and isoelectric point (pi) of 5.54, while ihomt2, which shares 31.5% amino acid sequen ... | 2008 | 17383769 |
| purification, properties and subunit structure of arginase from iris bulbs. | arginase (l-arginine amidinohydrolase, ec 3.5.3.1) from iris hollandica bulbs has been purified approximately 20 000-fold. the purification procedure involved extraction from a particulate fraction (probably mitochondria), deae-sephacel chromatography, aminohexyl-sepharose 4b chromatography and gel filtration on ultrogel aca 34. optimum assay conditions were determined, i.e. ph 9.0, 0.5 mm mn2+, 0.5 mm dithiothreitol. the arginase is a slightly acidic protein (pi approximately equal to 5.6) high ... | 1982 | 7140765 |
| iris bulbs express type 1 and type 2 ribosome-inactivating proteins with unusual properties. | two closely related lectins from bulbs of the dutch iris (iris hollandica var. professor blaauw) have been isolated and cloned. both lectins, called iris agglutinin b and iris agglutinin r, possess n-glycosidase activity and share a high sequence similarity with previously described type 2 ribosome-inactivating proteins (rip). however, these lectins show only 57% to 59% sequence identity to a previously characterized type 1 rip from iris, called irip. the identification of the iris lectins as ty ... | 2001 | 11161044 |
| delay of iris flower senescence by protease inhibitors. | visible senescence of the flag tepals in iris x hollandica (cv. blue magic) was preceded by a large increase in endoprotease activity. just before visible senescence about half of total endoprotease activity was apparently due to cysteine proteases, somewhat less than half to serine proteases, with a minor role of metalloproteases. treatment of isolated tepals with the purported serine protease inhibitors aebsf [4-(2-aminoethyl)-benzenesulfonyl fluoride] or dfp (diisopropyl-fluorophosphate) prev ... | 2005 | 15720658 |
| type-1 ribosome-inactivating protein from iris (iris hollandica var. professor blaauw) binds specific genomic dna fragments. | the capacity of irip, a type-1 ribosome-inactivating protein (rip) isolated from the bulbs of iris hollandica, to bind specific dna sequences from a mixture of approx. 200 bp (average length) fragments of total genomic dna from iris genome was studied. fragments that were preferentially bound by irip were enriched by several cycles of affinity binding and pcr, and were cloned and sequenced. the selected dna fragments do not share conserved sequences, indicating that irip does not bind dna fragme ... | 2001 | 11463360 |
| endogenous levels of abscisic acid and decanoic acid in dutch iris bulbs and the influence of abscisic acid and decanoic acid on iris meristems cultured in vitro. | abscisic acid (aba) and decanoic acid inhibited shoot elongation and floral development of dutch iris (iris hollandica hoog. cv ideal) meristems cultured in vitro. no synergism with respect to inhibition of leaf growth between aba and decanoic acid was observed. with monthly harvest dates, from july 10, 1981 to october 10, 1981, there was a progressive decrease in endogenous level of free aba in ;ideal' iris bulbs. bulbs subjected to a full set of the usual preplanting storage conditions flowere ... | 1983 | 16663072 |
| isolation and characterization of an n-acetyl-d-galactosamine-binding lectin from dutch iris bulbs which recognizes the blood group a disaccharide (galnac alpha 1-3gal). | a blood group type a disaccharide (galnac alpha 1-3gal)-binding lectin has been purified from dutch iris (iris x hollandica) bulbs to electrophoretic homogeneity by consecutive affinity chromatography on columns of immobilized asialofetuin-sepharose 4b and synsorb a disaccharide (galnac alpha 1-3gal beta-o-(ch2)8conh-synsorb). this lectin agglutinates both native and trypsin-treated rabbit erythrocytes, but not human erythrocytes, irrespective of blood group type. gel filtration chromatography o ... | 1994 | 8125993 |
| type 1 ribosome-inactivating proteins are the most abundant proteins in iris (iris hollandica var. professor blaauw) bulbs: characterization and molecular cloning. | the most abundant protein of iris bulbs has been identified as a type 1 ribosome-inactivating protein (rip). analysis of the purified proteins and molecular cloning of the corresponding cdnas demonstrated that this type 1 rip is a mixture of three isoforms that exhibit a high degree of sequence identity and have similar, though not identical, ribosome-inactivating and polynucleotide:adenosine glycosidase activities. the accumulation of large quantities of type 1 rip in a vegetative storage organ ... | 1997 | 9210423 |
| daffodil flowers delay senescence in cut iris flowers. | visible symptoms of tepal senescence in cut iris x hollandica (cv. blue magic) flowers were delayed by placing one cut daffodil flower (narcissus pseudonarcissus, cv. carlton) in the same vase. addition of mucilage, exuded by daffodil stems, to the vase water had the same effect as the flowering daffodil stem. the active compound in the mucilage was identified as narciclasine (using lc/ms, gc/ms, 1h and 13c-nmr, and comparison with an authentic sample of narciclasine). the delay of senescence, e ... | 2004 | 15003420 |
| microenvironment of cysteine 242 in type-1 ribosome-inactivating protein from iris. | irip is a type-1 ribosome-inactivating protein isolated from the bulbs of iris hollandica. it is one of the few type-1 rips that contain cys residue(s) in their primary sequence. irip contains a single cys residue at position 242. although irip is thought to be a monomeric protein, sds-page indicates that part of the irip molecules can exist as disulphide bridge-linked dimers. probing of the reactivity of the unique cys residue by 5, 5'-dithiobis(2-nitrobenzoic acid) indicates that cys(242) in i ... | 2000 | 10964691 |
| terpene biosynthesis in cell-free extracts and excised shoots from wedgwood iris. | excised shoots and cell-free extracts prepared from wedgwood iris (iris hollandica hoog. "wedgwood") shoots metabolized (14)c-labeled mevalonic acid (mva). by using cell-free extracts, the (14)c from mva-1-(14)c was recovered as (14)co(2), while that from mva-2-(14)c was recovered as neutral terpenes, acid-hydrolyzable terpenes, or (14)co(2). also, under optimal incubation conditions, 12.8 nanomoles r-mva-2-(14)c was incorporated into neutral terpenes per milligram fresh weight per hour. in cont ... | 1973 | 16658574 |
| biosynthesis of phenylalanine, tyrosine, 3-(3-carbocyphenyl) alanine and 3-(3-carbocy-4-hydroxyphenyl) alanine in higher plants. examples of the transformation possibilities for chorismic acid. | 14c-labelled shikimic acid and double labelled shikimic acid tritiated stereospicifically at c-6 are incorporated into 3-(3-carboxyphenyl) alanine, 3-(3-carboxy-4-hydroxyphenyl) alanine, phenylalanine, and tyrosine in reseda lutea l., reseda odorata l., iris x hollandica cv. prof. blauw, and iris x hollandica cv. wedgwood. the experiments with 14c-labelled shikimic acid confirm that the aromatic carboxyl groups and rings in 3-(3-carboxyphenyl) alanine and 3-(3-carbocy-4-hydroxyphenyl) alanine de ... | 1975 | 1120151 |
| gene expression during anthesis and senescence in iris flowers. | we investigated changes in gene expression in iris hollandica flowers by microarray technology. flag tepals were sampled daily, from three days prior to flower opening to the onset of visible senescence symptoms. gene expression profiles were compared with biochemical data including lipid and protein degradation and dna coiling, and with morphological data. plasmodesmata of mesophyll cells closed about two days before flower opening, while in the epidermis they closed concomitant with opening. s ... | 2003 | 15082930 |