Acid alcoholic brilliant cresyl blue stain for gastric and other mucins

Summary Some but not all samples of brilliant cresyl blue (6-methyl-7-dimethylamino-2-phenoxazin chloride) under C. I. No. 51010 in Conn's Biological Stains when dissolved at 1% level in 50–70% alcohol containing 1% concentrated (12 N) hydrochloric acid, stain (in 30 min) a wide variety of human and laboratory animal mucins blue black on an almost unstained background. The mucoprotein of the gastric surface epithelium and of the peptic gland neck cells of several species reacts strongly. A 16 hr 60° C methylation in 0.1 M methyl-sulfuric acid in methanol is required to block the staining of these gastric and some intestinal mucins, while 1–2 hr intervals suffice to prevent the staining of mast cells, cartilage and metachromatic sulfomucins generally. Saponification (1% KOH/70% alcohol, 20min) does not restore staining in either location group, indicating that sulfate mucins are probably reacting in both.Most other basic dyes fail to stain mucins from acid alcohol solutions: azure A, toluidine blue, resorcin blue, orcein, resorufin, azoresorufin brown, azolitmin, lacmoid, gallocyanin, Nile blue, methylene green, pararosanilin, crystal violet, Victoria blue R. Some staining occurred with one of three lots of Victoria blue B, with two lots of Victoria blue 4 R and with one lot each of Bernthsen's methylene violet, elastin violet PR and elastin purple PP.The stain may be preceded by the Feulgen reaction to give red nuclei, or followed by a brief collagen stain in an alcoholic acid fuchsin (0.05–0.1%), picric acid (1.5%) solution.Presented before the Symposium of the Histochemische Gesellschaft in Hamburg, 28. September 1968.Supported by National Cancer Institute Grant No. C-4816, National Institutes of Health.     

Light microscopic distinction between elastin,pseudo-elastica (type III collagen?) and interstitial collagen

Summary Distinction between elastin and collagen in arteriosclerotic lesions is difficult because the so-called elastica stains are bound also by collagen fibers which resemble collagen of premature infants. Investigations of effects of organic solvents on dye binding led to the development of methods for selective demonstration of pseudo-elastica, and for simultaneous visualization of elastin and pseudo-elastica in contrasting colors.Paraffin sections of human autopsy material were stained with solutions of resorcin-fuchsin, orcein or aldehyde fuchsin in absolute ethanol. In other series, sections pretreated with this resorcin-fuchsin solution were counter-stained with tannic acid-phosphomolybdic acid (TP)-dye technics.Solutions of these elastica stains in absolute ethanol colored only pseudo-elastica; elastin, e.g. elastic membranes of aorta, remained unstained. In sections counterstained with TP-dye technics elastin was colored red; pseudo-elastica retained the purplish blue coloration imparted by resorcinfuchsin. Other collagens were stained yellow.A review of the literature showed that until the 1920's elastin was classified as a gelatinoid of the collagen group. Elastic fibers were identified by mechanical properties, not a particular chemical composition. Hence, the elastic fibers of classical histology cannot be equated with the elastin of modern chemistry. Correlation of histochemical observations with chemical data indicates that the collagenous pseudo-elastica corresponds to [1(III)]₃ collagen.     

A novel 2-aminophenol 1,6-dioxygenase involved in the degradation of p-chloronitrobenzene by Comamonas strain CNB-1: purification, properties, genetic cloning and expression in Escherichia coli

Comamonas strain CNB-1 was isolated from a biological reactor treating wastewater from a p-chloronitrobenzene production factory. Strain CNB-1 used p-chloronitrobenzene as sole source of carbon, nitrogen, and energy. A 2-aminophenol 1,6-dioxygenase was purified from cells of strain CNB-1. The purified 2-aminophenol 1,6-dioxygenase had a native molecular mass of 130 kDa and was composed of - and -subunits of 33 and 38 kDa, respectively. This enzyme is different from currently known 2-aminophenol 1,6-dioxygenases in that it: (a) has a higher affinity for 2-amino-5-chlorophenol (K_m=0.77 M) than for 2-aminophenol (K_m=0.89 M) and (b) utilized protocatechuate as a substrate. These results suggested that 2-amino-5-chlorophenol, an intermediate during p-chloronitrobenzene degradation, is the natural substrate for this enzyme. N-terminal amino acids of the - and -subunits were determined to be T-V-V-S-A-F-L-V and M-Q-G-E-I-I-A-E, respectively. A cosmid library was constructed from the total DNA of strain CNB-1 and three clones (BG-1, BG-2, and CG-13) with 2-aminophenol 1,6-dioxygenase activities were obtained. DNA sequencing of clone BG-2 revealed a 15-kb fragment that contained two ORFs, ORF9 and ORF10, with N-terminal amino acid sequences identical to those of the - and -subunits, respectively, from the purified 2-aminophenol 1,6-dioxygenase. The enzyme was actively synthesized when the genes coding for the ORF9 and ORF10 were cloned into Escherichia coli.     

Der Abbau von phenolischen Substanzen durch Aspergillus niger

Zusammenfassung Es wurde gezeigt, daß Aspergillus niger XLI A ₁ mit Gallussäure, Pyrogallol, Resorcin oder Hydrochinon als einziger Kohlenstoffquelle wachsen kann. Nach Arsenithemmung konnte aus den Resorcin- und Hydrochinonkulturen Lävulinsäure-2,4-Dinitrophenylhydrazon isoliert werden, das vermutlich aus -Ketoadipinsäure entstanden war. Der Abbaumechanismus der phenolischen Substanzen durch Aspergillus niger wird diskutiert.     

Photomorphogenic effects on in vitro rooting of Prunus roostock GF 655-2

The morphogenic effect of different light wavelengths on in vitro rooting of Prunus insititia GF655-2 in relation to the presence of napthaleneacetic acid (NAA) in the culture medium was investigated. Results of experiments in which plantlets were rooted in NAA enriched medium showed that the presence of auxin induced rooting even in the dark after an initial lag period. Illumination of the cultures with Red light was as effective in promoting rooting as treatment with 0.5 M NAA; Red was more active in stimulating rooting in the short term than was NAA. The pattern of root formation resulting from the addition of NAA appeared to dominate development under White, Blue and Far Red treatments. Although it was possible to correlate the rooting response to the phytochrome photoequilibrium induced by the light treatments used, there arises a possible interference of specific Blue absorbing photoreceptors.Abbreviations B Blue - FR Far Red - HIR High Irradiance Response - P_fr active (far-red absorbing) form of phytochrome - P_tot total phytochrome - R Red - W White - NAA -naphtaleneacetic acid - BA benzyladenine - IAA indole 3-acetic acid     

DNA sequence analysis of the rat RT1. B α gene

The major histocompatibility complex (MHC) of the rat (RT1 complex) encodes two sets of class II molecules referred to as RT1.B and RT1.D. The RT1. B gene was isolated for a Sprague-Dawley (RT1^b) rat genomic library using a rat RT1.B chain cDNA as a hybridization probe. The coding and the majority of the intron DNA sequence was determined. The structure of the RT1. B gene is equivalent to that of H-2 and HLA chain genes. Comparison of the nucleotide and predicted amino acid sequences of the RT1.B gene with those of the H-2 and HLA genes revealed a high degree of overall sequence conservation. However, two regions of the first external domain (l), residues 19–23 and 45–78, exhibit marked sequence variation. Two blocks of conserved nucleotide sequence were identified in the 5 promoter region of the RT1. B gene that have been described in all MHC class II genes sequenced to date. These conserved sequences may be involved in the coordinate regulation of expression of class II genes. The cloned RT1.B gene was efficiently transcribed when transfected to mouse L cells.     

Tryptophan Production by a Lipoic Acid Auxotroph of Enterobacter aerogenes Having Both Pyruvic Acid Productivity and High Tryptophanase Activity

A new process for tryptophan production was established using a lipoic acid auxotrophic mutant, Enterobacter aerogenes l-12, which has both pyruvic acid productivity and tryptophanase activity. The process consists of the production of pyruvic acid from glucose by the washed cells and the subsequent conversion of the acid to tryptophan by the tryptophanase itself in the presence of indole and NH₄C1.

To prepare washed cells of which the tryptophanase activity and the pyruvic acid productivity were both high, it was best to culture the strain in a medium containing 1 % Polypepton, 0.2 % glucose, 3 μg/1 dl-lipoic acid, 0.05 % l-tryptophan, and mineral salts. The optimum composition of the reaction mixture for the pyruvic acid production by the washed cells was established. Under these conditions, 17 g/1 of pyruvic acid was accumulated from 5 % glucose after 36 hr of incubation. Thus, the conversion of the pyruvic acid to tryptophan was done by adding indole, NH₄C1, pyridoxal-5′-phosphate, Triton X-100, and KOH to adjust the pH to 9.0 to the above reaction mixture. As a result, the pyruvic acid was rapidly converted to tryptophan, and the concentration of 14 g/1 was obtained after 36 hr (total 72 hr).     

Orcein,collastin and pseudo-elastica: a re-investigation of Unna's concepts

Summary Orcein has been recommended for identification of elastin. Since other traditional elastica stains proved to be unspecific, it was deemed of interest to determine the selectivity of orcein and to review pertinent literature.Orcein was employed as a textile dye in ancient Egypt and was used for dyeing of wool and silk until the early 20th century. It was introduced into histological technic in 1878 as a stain for cytoplasm. Unna recommended it for demonstration of elastic tissue in 1890 and retracted claims for its specifity in 1894 because orcein colored also certain collagen fibers. Unna suggested the term collastin for collagen fibers which share the affinity of elastin for acid orcein. Other orcein solutions were used as selective stains for collagen.In histochemical studies, the staining properties of resorcin-fuchsin and orcein were very similar; elastin and various collagen fibers were strongly colored. Unna's collastin is apparently identical with the pseudo-elastica described in sections stained with resorcin-fuchsin. Both dyes react with meshworks of fine fibers, embryonic, experimentally or pathologically altered collagens. It is suggested to use the term collastin, instead of pseudo-elastica, for collagenous fibers which bind the traditional elastica stains.     

Orcein, collastin and pseudo-elastica: a re-investigation of Unna's concepts.

Orcein has been recommended for identification of elastin. Since other traditional elastica stains proved to be unspecific, it was deemed of interest to determine the selectivity of orcein and to review pertinent literature. Orcein was employed as a textile dye in ancient Egypt and was used for dyeing of wool and silk until the early 20th century. It was introduced into histological technic in 1878 as a stain for cytoplasm. Unna recommended it for demonstration of elastic tissue in 1890 and retracted claims for its specifity in 1894 because orcein colored also certain collagen fibers. Unna suggested the term collastin for collagen fibers which share the affinity of elastin for acid orcein. Other orcein solutions were used as selective stains for collagen. In histochemical studies, the staining properties of resorcin-fuchsin and orcein were very similar; elastin and various collagen fibers were strongly colored. Unna's collastin is apparently identical with the pseudo-elastica described in sections stained with resorcin-fuchsin. Both dyes react with meshworks of fine fibers, embryonic, experimentally or pathologically altered collagens. It is suggested to use the term collastin, instead of pseudo-elastica, for collagenous fibers which bind the traditional elastica stains.     

Fine structural and enzymehistochemical observations on the notochord of Ichthyophis glutinosus and Ichthyophis kohtaoensis (Gymnophiona,Amphibia)

Summary The notochord of Ichthyophis glutinosus and I. kohtaoensis consists of peripheral flattened cells characterized by a well-developed system of rough endoplasmic reticulum, bundles of tonofilaments, and abundant glycogen particles. These cells contain furthermore fairly high activities of -naphtyl-acetate esterase and 4-chloro-5-bromoindoxyl acetate esterase as well as acid phosphatase which was found in lysosomal localization. The huge intracellular vacuoles of the centrally situated cells possibly originate from electron translucent spaces within the glycogen fields of the peripheral cells.The notochord sheath consists of variously differentiated layers of collagen fibers and of an elastica externa. The diameters of the collagen fibers increase from the inner towards the outer region of the sheath. A peculiar feature of the Ichthyophis notochord sheath is a ring of mineralized collagen. The notochord of the caecilians investigated is compared with that of anurans, urodeles, and several groups of fish.Supported by the Deutsche Forschungsgemeinschaft.     

Blue Pigment Formation by Clerodendron trichotomum callus

Blue pigment-producing callus was induced from fruit of Clerodendron trichotomum Thunb. on Linsmaier and Skoog (LS) medium with 10 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Callus grew on LS medium with either 2,4-D or 1-naphthaleneacetic acid (NAA) on subculture. Callus growth and blue pigment formation were much improved by selection on LS gellan gum medium with 2 μM NAA. Kinetin and benzyladenine (1 μM) inhibited blue pigment formation. One of the blue pigments was confirmed to be trichotomine by HPLC, TLC, and NMR spectra; two others were presumed to be trichotomine G₁ and N,N′-di(D-glucopyranosyl)trichotomine on the basis of comparison with the blue pigments from C. trichotomum fruit on HPLC.     

Cell wall teichoic acids from Streptomyces daghestanicus VKM Ac-1722T and streptomyces murinus INA-00524T

The structure of cell wall teichoic acids was studied by chemical methods and NMR spectroscopy in the type strains of two actinomycete species of the Streptomyces griseoviridis phenetic cluster: streptomyces daghestanicus and streptomyces murinus. S. daghestanicus VKM Ac-1722^t contained two polymers having a 1,5-poly(ribitol phosphate) structure. In one of them, the ribitol units had -rhamnopyranose and 3-O-methyl--rhamnopyranose substituents; in the other, each ribitol unit was carrying 2,4-ketal-bound pyruvic acid. Such polymers were earlier found in the cell walls of Streptomyces roseolus and Nocardiopsis albus, respectively; however, their simultaneous presence in the cell wall has never been reported. The cell wall teichoic acid of Streptomyces murinus INA-00524^T was a 1,5-poly(glucosylpolyol phosphate), whose repeating unit was [-6)--D-glucopyranosyl-(12)-glycerol phosphate-(3-P-]. Such a teichoic acid was earlier found in Spirilliplanes yamanashiensis. The ¹³C NMR spectrum of this polymer is presented for the first time. The results of the present investigation, together with earlier published data, show that the type strains of four species of the Streptomyces griseoviridis phenetic cluster differ in the composition and structure of their teichoic acids; thus, teichoic acids may serve as chemotaxonomic markers of the species.Translated from Mikrobiologiya, Vol. 74, No. 1, 2005, pp. 48–54.Original Russian Text Copyright © 2005 by Streshinskaya, Kozlova, Alferova, Shashkov, Evtushenko.     

Characterization of the Na+-dependent taurine influx in flounder erythrocytes

About 92% of the taurine influx in flounder erythrocytes at physiological conditions in vitro (330 mosmol·l^-1, 145 mmol·l^-1 Na⁺, 0.30 mmol·l^-1 taurine) is Na⁺-dependent. This influx is highly specific for taurine. The -amino compounds hypotaurine and -alanine were the only compounds which mimicked the inhibitory effect of taurine on influx of [¹⁴C]taurine, the former more than the latter. Counterexchange of taurine was also mediated by the taurine transporters. Reduction of osmolality per se did not affect the activity of these transporters. Non-linear regression analysis of the influx values revealed the presence of two different influx systems: a system with high affinity and low capacity and another with low affinity and high capacity. However, we cannot exclude the possibility that this influx of taurine was mediated by only one transporter which operated in different modes depending on the extracellular Na⁺ concentration. On the assumption that the Na⁺-dependent influx was mediated by two separate systems, the maximal velocity of the low capacity system was 2.55 nmol·g dry weight^-1·min^-1 at 145 mmol·ll^-1 extracellular Na⁺. This capacity was about 50% lower than that of the high capacity system. The Michaelis constants were 0.013 and 1.34 mmol·l^-1, respectively. Reduction of the extracellular Na⁺ concentration reduced maximal velocity and the affinity to taurine of both transport systems. At 10 mmol·l^-1 Na⁺ or lower concentrations the high capacity system did not seem to operate. The activation method suggested that each taurine molecule transported by the high capacity system was accompanied by two Na⁺. The stoichiometry of the low capacity system was 1 taurine: 1 Na⁺. The Hill-coefficient for both transport systems was 1.00.Abbreviations cpm counts per minute - dw dry weight - GABA -amino-n-butyric acid - K _m Michaelis constant - pK _b basic dissociation constant - SD standard deviation - -ABA Dl--amino-n-butyric acid - V _max maximal velocity - ww wet weight     

A modified unstructured mathemathical model for the penicillin G fed-batch fermentation

Summary In this paper, an updated unstructured mathematical model for the penicillin G fed-batch fermentation is proposed, in order to correct some physical and biochemical shortcomings in the model of Heijnen et al. (1979,Biotechnol. Bioeng.,21, 2175–2201) and the model of Bajpai and Reuß (1980,J. Chem. Tech. Biotechnol.,30, 332–344). Its main features are the consistency for all values of the variables, and the ability to adequately describe different metabolic conditions of the mould. The model presented here can be considered as the translation of the latest advances in the biochemical knowledge of the penicillin biosynthesis.Nomenclature t time (h) - S amount of substrate in broth (g) - X amount of cell mass in broth (g) - P amount of product in broth (g) - V fermentor volume (L) - F input substrate feed rate (L/hr) - C _s S/V substrate concentration in broth (g/L) - C _x X/V cell mass concentration in broth (g/L) - C _P P/V product concentration in broth (g/L) - s _F substrate concentration in feed stream (g/L) - E _m parameter related to the endogenous fraction of maintenance (g/L) - E _p parameter related to the endogenous fraction of production (g/L) - K _x Contois saturation constant for substrate limitation of biomass production (g/g DM) - K _s Monod saturation constant for substrate limitation of biomss production (g/L) - K _p saturation constant for substrate limitation of product formation (g/L) - K _i substrate inhibition constant for product formation (g/L) - m _s maintenance constant (g/g DM hr) - k _h penicillin hydrolysis or degradation constant (hr^–1) - Y _x/s cell mass on substrate yield (g DM/g) - Y _p/s product on substrate yield (g/g) - specific substrate consumption rate (g/g DM hr) - specific growth rate (hr^–1) - _substr specific substrate to biomass conversion rate (hr^–1) - _x maximum specific substrate to biomass conversion rate (hr^–1) - specific production rate (g/g DM hr) - _p specific production constant (g/g DM hr)     

Role of anions in the lymphocytolytic action of corticosteroids and fatty acids

Summary Rat thymocytes were exposed in vitro to the corticosteroid dexamethasone, 10 nM, for 10 min, or to oleic acid, 500 nM for 2 min. This results in cytolysis after 6 hr, if incubation is continued. Instead, the cells were centrifuged, the supernatant fluid decanted, and the cells subjected to osmotic shock in 1.5 MM MgCl₂. The naked nuclei were incubated at 37 °C and examined by light and electron microscopy. Nuclear edema was evident early, and most nuclei showed damage with variation in shape and size and distinct folds, which was maximal by 1–2 hr as a result of these treatments. This was true also if nuclei were incubated in MgF₂ or Mg(N0₃)₂ but not in MgBr₂, MgI₂, MgSO₄ or Mg-citrate. Spleen lymphocyte nuclei showed similar damage but only after incubation with 20 µM oleic acid, and not at all with corticosteroids. The effects of both steroid and fatty acid, even at greatly increased concentrations, were inhibited by tri-n-butyl tin chloride, 10 µM, and by 4-4-diisothiocyanostilbene-2, 2-disulfonic acid, sodium salt, 10 µM, both of which block chloride ion transport. It is concluded that the cytolytic effects of both corticosteroids and free fatty acids involve influx of chloride ion resulting in nuclear edema, which subsequently leads to frabinentation of chromatin, karyorrhexis and, ultimately, cytolysis.     

The effect of triiodothyronine on glucose utilization in adipocytes from obese rats

• 1.1. In the presence of insulin, 10⁻⁵ M 3,3',5-triiodothyronine (T₃) treatment for 1/2 hr decreased fatty acid synthesis 35% only in adipocytes from lean rats, whereas at 10⁻¹¹ M through 10⁻⁷M T₃ the obese adipocytes had nearly a 20% increase in fatty acid synthesis.
• 2.2. A 2 hr pretreatment of adipocytes with 10⁻⁹ and 10⁻⁷ M T₃ decreased insulin-stimulated fatty acid synthesis by nearly 20% in both lean and obese adipocytes.
• 3.3. In the absence of insulin, the 2 hr pretreatment with 10⁻⁹ M T₃ resulted in a 45% increase in lean adipocyte fatty acid synthesis, though the obese adipocytes required at least 10⁻⁷ M T₃ for 2 hr to increase the non-insulin-stimulated fatty acid synthesis by 50%.
• 4.4. At 10⁻⁹M T₃ concentrations non-insulin-stimulated fatty acid synthesis was increased by 200% in lean adipose tissue explants, but obese adipose expiants were not significantly affected under these conditions.
• 5.5. The addition of 10⁻⁹ M T₃ plus insulin to the explant media decreased fatty acid synthesis by 35% in both the lean and obese tissues.
• 6.6. The results also imply that the low T₃ status of the obese rat may be contributory to the elevated fatty acid synthesis observed in obese adipocytes.

     

Altered structure of HLA class I heavy chains associated with mouse beta-2 microglobulin

The serological reactivities of HLA-A3, -B7, and -CW3 heavy chains associated with either mouse, bovine, or human beta-2 microglobulin ( ₂m) and expressed on the surface of transfected mouse fibroblasts were analyzed. All reactivities associated with one cluster (defined by monoclonal antibody W6/32) of antigenic determinants expressed by these HLA class I molecules were lost, or profoundly reduced, after each heavy chain associated with mouse ₂-m. Expression by the transfected fibroblasts of the HLA-A3, -B7, and -CW3 heavy chains in association with human ₂m restores these reactivities. Since most of the amino acid differences between mouse and human ₂m probably correspond to externally oriented hydrophilic residues, these results suggest that critical interactions in the three-dimensional structure of HLA class I molecules occur between the light chain and the first two external domains of the class I heavy chains, to which some of the altered reactivities have been mapped.     

N-Oxidation of arylamines to nitrosobenzenes using chloroperoxidase purified from Musa paradisiaca stem juice

Abstract

N-Oxidation of arylamines to their corresponding nitrosobenzenes using a new chloroperoxidase purified from Musa paradisiaca stem juice has been examined. The enzymatic characteristics of the stem chloroperoxidase using 4-chloroaniline as substrate were determined. The K_m values for 4-chloroaniline and H₂O₂ were 770 μM and 154 μM respectively, while the pH and temperature optima were 4.4 and 30°C respectively. The substrate specificities of the enzyme for the arylamines 3,4-dichloroamine, p-aminobenzoic acid, p-toluidine, p-anisidine, m-anisidine, p-aminophenol, o-aminophenol and m-aminophenol have been characterized. The feasibility of using concentrated M. paradisiaca stem juice for the specific conversion of 4-chloroaniline to 4-chloronitrosobenzene has been demonstrated. This enzyme can be used for the N-oxidation of other arylamines.     

Effect of gibberellic acid on photosynthesis and glycollate dehydrogenase in Anacystis nidulans

Gibberellic acid at 10^-4 Mxxx was optimal for enhancement of growth, O₂ evolution, photosystem II and I and the activity of glycollate dehydrogenase of Anacystis nidulans. A stimulatory effect was observed on photosystem II. Other concentrations of gibberellic acid were inhibitory to O₂ evolution and photosystem I. Syntheses of phycocyanin, phycoerythrin and -carotene were significantly enhanced after 48 h incubation with gibberellic acid at 10^-3 Mxxx but the chlorophyll content began to increase 3 h after adding 10^-4 Mxxx gibberellic acid.The author is with the Department of Biological Sciences, Faculty of Science, University of Science and Technology, Irbid, Jordan.     

The biosynthesis and conjugation of indole-3-acetic acid in germinating seed and seedlings ofDalbergia dolichopetala

Germinating seed ofDalbergia dolichopetala converted both [²H₅]l-tryptophan and [²H₅]indole-3-ethanol to [²H₅]indole-3-acetic acid (IAA). Metabolism of [2-¹⁴C]IAA resulted in the production of indole-3-acetylaspartic acid (IAAsp), as well as several unidentified components, referred to as metabolites I, II, IV and V. Re-application of [¹⁴C]IAAsp to the germinating seed led to the accumulation of the polar, water-soluble compound, metabolite V, as the major metabolite, together with a small amount of IAA. Metabolites I, II and IV were not detected, nor were these compounds associated with the metabolism of [2-¹⁴C]IAA by shoots and excised cotyledons and roots from 26-d-oldD. dolichopetala seedlings. Both shoots and cotyledons converted IAA to IAAsp and metabolite V, while IAAsp was the only metabolite detected in extracts from excised roots. The available evidence indicates that inDalbergia, and other species, IAAsp may not act as a storage product that can be hydrolysed to provide the plant with a ready supply of IAA.Abbreviations HPLC-RC high-performance liquid chromatography-radiocounting - IAA indole-3-acetic acid - IAAsp indole-3-acetylaspartic acid - IAlnos 2-O-indole-3-acetyl-myo-inositol - IEt indole-3-ethanol