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PubMed1992

Inhibition of Gibberellin Production in the Fungi Gibberella fujikuroi and Sphaceloma manihoticola by Plant Growth Retardants.

The effect of different types of plant growth retardants on fungal gibberellin (GA) formation has been studied in cultures of Gibberella fujikuroi and Sphaceloma manihoticola. Quaternary ammonium compounds (chlormequat chloride, mepiquat chloride, Amo-1618), triazoles (uniconazole and several experimental compounds), and the norbornanodiazetine tetcyclacis inhibited GA biosynthesis in both fungal species. Concentrations between 2 x 10(-4) and 10(-9)m were required for a 50% inhibition of the production of gibberellin A(3) in Gibberella fujikuroi and of giberellin A(4) in Sphaceloma manihoticola. The formation of other prominent GAs was affected at a similar degree of intensity. Tetcyclacis was the most active compound in both fungi. Compared to the growth retardants mentioned above, the biological activity of chlorphonium chloride was low. The acylcyclohexanediones prohexadione and LAB 198 999 had virtually no activity. Most likely, this lack of activity is due to a rapid metabolism of the compounds in the cultures. For the triazole-type compounds and tetcyclacis, a relatively distinct correlation exists in their ability to inhibit GA formation in fungal cultures, to block ent-kaurene oxygenase in a cell-free system, and to reduce shoot growth of rice seedlings. Due to differences in their metabolic fate and species specificities, such conclusions cannot be made for the other compounds.

Journal Article↗
PubMed1979

Temperature Interactions with Growth Regulators and Endogenous Gibberellin-like Activity during Seedstalk Elongation in Carrots.

Stecklings (roots) of three cultivars of carrots (Daucus carota L.) were vernalized 10 weeks at 5 C and subsequently grown at each of three greenhouse night/day temperature regimes: high (27/32 C), medium (21/27 C), and low (15/21 C). Floral differentiation occurred first in the easy bolting cv. Scarlet Nantes, intermediate in cv. Danvers 126, and last in cv. Royal Chantenay. Stem elongation arising from the subapical meristematic region always preceded floral differentiation. Extractable gibberellin-like activity in carrot stem apices increased from harvest during the 10-week vernalization period, then remained constant even though floral differentiation and stem elongation occurred during an additional 20-week cold storage period. Low temperature had both an inductive and a direct effect on reproductive development depending on length of low temperature exposure.After 10 weeks vernalization at 5 C, high greenhouse temperature severely reduced ultimate seedstalk height and the endogenous gibberellinlike activity decreased rapidly during the first 3 weeks in the greenhouse. At the low greenhouse temperature, activity remained fairly constant during the 10-week sampling period. Changes in endogenous gibberellinlike activity were related with stem elongation, but not with floral initiation. Exogenous gibberellic acid (GA(3)) applied following vernalization prevented the inhibitory effect of high greenhouse temperature on seedstalk elongation and resulted in seedstalk heights comparable to untreated controls grown at the low greenhouse temperature. Exogenous applications of succinic acid-2,2-dimethylhydrazide and chlormequat reduced seedstalk height of carrot plants grown at the medium and low greenhouse temperatures to that of untreated controls grown at high temperature. Exogenous growth regulators and greenhouse temperature affected seedstalk elongation, but did not affect the number of plants that flowered.

Journal Article↗
PubMed2000

GROWTH RETARDANTS: Effects on Gibberellin Biosynthesis and Other Metabolic Pathways.

Plant growth retardants are applied in agronomic and horticultural crops to reduce unwanted longitudinal shoot growth without lowering plant productivity. Most growth retardants act by inhibiting gibberellin (GA) biosynthesis. To date, four different types of such inhibitors are known: (a) Onium compounds, such as chlormequat chloride, mepiquat chloride, chlorphonium, and AMO-1618, which block the cyclases copalyl-diphosphate synthase and ent-kaurene synthase involved in the early steps of GA metabolism. (b) Compounds with an N-containing heterocycle, e.g. ancymidol, flurprimidol, tetcyclacis, paclobutrazol, uniconazole-P, and inabenfide. These retardants block cytochrome P450-dependent monooxygenases, thereby inhibiting oxidation of ent-kaurene into ent-kaurenoic acid. (c) Structural mimics of 2-oxoglutaric acid, which is the co-substrate of dioxygenases that catalyze late steps of GA formation. Acylcyclohexanediones, e.g. prohexadione-Ca and trinexapac-ethyl and daminozide, block particularly 3ss-hydroxylation, thereby inhibiting the formation of highly active GAs from inactive precursors, and (d) 16,17-Dihydro-GA5 and related structures act most likely by mimicking the GA precursor substrate of the same dioxygenases. Enzymes, similar to the ones involved in GA biosynthesis, are also of importance in the formation of abscisic acid, ethylene, sterols, flavonoids, and other plant constituents. Changes in the levels of these compounds found after treatment with growth retardants can mostly be explained by side activities on such enzymes.

Journal Article↗
PubMed2004

High mass accuracy in-source collision-induced dissociation tandem mass spectrometry and multi-step mass spectrometry as complementary tools for fragmentation studies of quaternary ammonium herbicides.

Fragmentation studies using both an ion-trap mass analyzer and a hybrid quadrupole time-of-flight (Q-TOF) mass spectrometer were performed in order to establish the fragmentation pathways of organic molecules. A general strategy combining MSn data (n = 1-4) in an ion-trap analyzer with tandem mass spectrometry and in-source collision-induced dissociation tandem mass spectrometry (CID MS/MS) in a Q-TOF instrument was applied. The MSn data were used to propose a tentative fragmentation pathway following genealogical relationships. When several assignments were possible, MS/MS and in-source CID MS/MS (Q-TOF) allowed the elemental compositions of the fragments to be confirmed. Quaternary ammonium herbicides (quats) were used as test compounds and their fragmentation pathways were established. The elemental composition of the fragments was confirmed using the TOF analyzer with relative errors <0.0023 Da. Some fragments previously reported in the literature were reassigned taking advantage of the high mass resolution and accuracy of the Q-TOF instrument, which made it possible to solve losses where nitrogen was involved.

Chlormequat↗
PubMed1975

Biological changes in the rhizosphere of wheat after foliar application of chlorocholinechloride, urea and 4-chloro-2-methylphenoxyacetic acid.

In field experiments wheat in the phase of shooting was sprayed with solutions of chlorocholinechloride (CCC) and urea, CCC and ammonium salt MCPA (Aminex) or CCC, urea and Aminex. The effect of the treatment on dry weight of overground parts of wheat, number of bacteria, production of carbon dioxide, urease activity and content of ammonium in the rhizosphere soil was investigated. In all cases evolution of carbon dioxide in the rhizosphere soil was higher than that in the control soil. Highest numbers of bacteria were found in the rhizosphere soil of plants treated with urea, the herbicide and their mixtures. Content of ammonium was higher in the control soil than in the rhizosphere soils, the urease activity was highest in the rhizosphere soil of plants treated with the solution of the herbicide and with the combination of the herbicide with urea.

Ammonia↗
PubMed1976

Mutagenic actions of chlorocholine chloride.

Chlorocholine chloride, at concentrations of 0.2 to 0.5 M (3.2 to 7.9%) between pH 5 and 8, showed no significant mutagenic effect whereas at the same concentrations at pH 9 it caused mutations, in a valine-sensitive strain of E. coli K12. Treatment of E. coli B with chlorocholine chloride at 0.5 M and pH 9 resulted in auxotrophic and regulatory deficient (valine-sensitive) mutants. The mutagenic effects of chlorocholine chloride were compared with the effects caused by the food additive NaHSO3.

Chlormequat↗
PubMed1984

Influence of feeding chlorocholine chloride and glyphosine on selected immune parameters in deer mice, Peromyscus maniculatus.

Exposure to the plant growth regulators, chlorocholine chloride (CCC) and glyphosine (GPS), resulted in significant immunomodulatory effects after feeding to deer mice (Peromyscus maniculatus) for 28 days. Cyclophosphamide (CP) and saline controls were included. Both CCC and GPS feeding levels were equivalent to 1, 10, 20, 40 and 80 mg/kg mouse/day. The parameters assessed were: spleen plaque forming cell (PFC) assays, hemolysin titers, white blood cell counts, bone marrow cellularity, hematocrits, plasma proteins, and spleen, liver, kidney, thymus and body weights. GPS significantly raised the ratio of liver/body wt, lymphocytes/g of spleen (at high doses only) and hemolysin titers (at low doses only). Lymphocyte viability was significantly reduced, while WBC counts and plasma protein levels were moderately lowered. CCC significantly reduced plasma proteins, PFCs/g of spleen, lymphocyte viability and hemolysin titers. It also affected thymus weights, WBC counts, lymphocytes/g of spleen and PFCs/10(6) lymphocytes. Most of the effects for both compounds followed a typical dose-response curve, but GPS gave a bimodal response in certain tests. The results demonstrate that CCC and GPS can act as immunomodulatory agents and show the feasibility of using deer mice for immunotoxicity studies of environmental contaminants and agricultural chemicals.

Animals↗
PubMed1984

Effects of ingestion of chlorocholine chloride and cyclophosphamide on Venezuelan equine encephalitis virus infections in deer mice (Peromyscus maniculatus).

We investigated the effects of chlorocholine chloride (CCC), a plant growth regulator, and cyclophosphamide (CP), a known immunosuppressant, on the ability of deer mice (Peromyscus maniculatus) to resist challenge with a sublethal dose of Venezuelan equine encephalitis virus ( VEEV ). The toxicants were continuously delivered in low doses in the feed; CP at 20 mg/kg body wt/day and CCC at 1, 10, 20 or 40 mg/kg body wt/day. Mice were inoculated with 3 X 10(4) plaque forming units (pfu) of VEEV after eating experimental feed for 23 days. Mice were bled daily for 7 days and at selected intervals from 8 to 63 days post inoculation (PI) for viremia and antibody titer determinations. CP treatment increased the duration of viremia and significantly (P less than or equal to 0.05) decreased mean viremia titers. Antibody titers were significantly (P less than or equal to 0.05) depressed in CP-treated mice compared to controls. CP treatment increased mortality. CCC had no effect on viremia duration or titer except when given in doses of 1 mg/kg body wt/day when it significantly (P less than or equal to 0.05) decreased mean viremia titers compared to controls. Early antibody responses were increased by CCC treatment except in the 10 mg/kg body wt/day treatment group in which titers were decreased. By 30 days PI antibody titers of CCC-treated mice were no different from controls.

Animals↗
PubMedDate not supplied

Influence of chlorocholinechloride-treated wheat on selected in vitro fertility parameters in male mice.

The aim of this study was to evaluate the influence of feeding with food and water containing chlorocholinechloride (CCC) on the fertility of male mice in a two-generation study. For this purpose the number of testicular spermatozoa and the relative proportion of primary and secondary spermatocytes involved in spermatogenesis were measured. Furthermore, the fertility of epididymal spermatozoa from tested male mice was investigated in a special in-vitro fertilization system. The experimental food was composed of CCC-treated wheat in the first experiment and CCC-free wheat and water mixed with pure CCC in the second experiment. The CCC residue content in the treated food and water was 0.21 mg/kg and 0.2 mg/L, respectively. Under the influence of feeding with CCC-treated wheat (Experiment 1) the fertilization and cleavage rates of oocytes incubated with spermatozoa from CCC-fed mice were reduced: the fertilization rate 65.1% vs. 21.1% and the cleavage rate 51.9% vs. 20.3%, p < 0.01 (control feeding vs. CCC feeding, respectively). Feeding of sperm donors with pure CCC mixed with untreated wheat pellets or water (Experiment 2) led to a reduction in the fertilization and cleavage rate (control: 60.8%, 32.4%; CCC-food: 29.8%, 12.1%; CCC-water: 30.1%, 10.2%; CCC-food/water: 36.6%, 12.5%; p < 0.01, respectively). The normal course of spermatogenesis was unchanged after the exposure to CCC. Testicular weight, the number of spermatozoa, and the proportion of haploid, diploid, and tetraploid testicular cells were not influenced. However, the functional competence of epididymal spermatozoa from CCC-fed donors was reduced, resulting in a significantly diminished fertilization and cleavage rate in vitro. The results suggest that CCC could interfere with epididymal protein secretion and the process of sperm maturation during passage through the epididymis.

Administration, Oral↗
PubMed2005

Life- cycle assessment in pesticide product development: methods and case study on two plant-growth regulators from different product generations.

Environmental assessments in pesticide product development are generally restricted to plant uptake and emissions of active ingredients. Life-cycle assessment (LCA) enables a more comprehensive evaluation by additionally assessing the impacts of pesticide production and application (e.g. tractor operations). The use of LCA in the product development of pesticides, in addition to the methods commonly applied, is therefore advisable. In this paper a procedure for conducting LCA in early phases of product development is proposed. In a case study, two plant-growth regulators from different product generations were compared regarding their application in intensive production of winter wheat. The results showed thatthe reduced emissions from active ingredients of the newer pesticide were compensated by higher impacts from the production process. The authors draw the conclusion that it is important to consider environmental objectives in the procurement of precursors, in addition to the classical goals of increasing the efficacy and reducing the nontarget effects of pesticides. Moreover, the case study showed that decisions based on uncertain results in early stages of product development may need to be revised in later stages, e.g. based on investigations of pesticides' effects on crop yield.

Chlormequat↗
PubMed2003

Inhibitor studies of isopentenyl pyrophosphate biosynthesis in suspension cultures of the yew Taxus chinensis var. mairei.

Some metabolic inhibitors, mevastatin (MVS), chlorocholine chloride (CCC), sodium pyrophosphate (NaPP) and D,L-glyceraldehyde (DLG), were respectively added into the suspension cultures of the yew Taxus chinensis var. mairei at the late phase of cell growth to study isopentenyl pyrophosphate (IPP) biosynthesis. The content of total taxanes decreased in the cases of MVS, NaPP and DLG addition, regardless of the inhibitor concentration, whereas it increased in the case of CCC addition. It was thus presumed that a mevalonate pathway might exist in IPP biosynthesis at the late growth phase of Taxus cells and that some IPP might transfer from the cytoplasm to the plastids. This presumption was also confirmed by analysing the effects of the inhibitors on taxane content. It was further demonstrated that IPP in the biosynthesis of taxol, baccatin III and 10-deacetylbaccatin III might transfer from the cytoplasm to the plastids, whereas the translocation of IPP might be not involved in cephalomannine biosynthesis. Furthermore, in combination with the results of previous studies, it is very probable that different IPP biosynthesis pathways exist during different growth phases in Taxus cells.

Bridged-Ring Compounds↗
PubMed2001

The effect of chlorocholine chloride (CCC) inclusion in the diets of growing hens on growth rate, oestrogen levels and the onset of lay.

A study was conducted to test the effect of chlorocholine chloride (CCC) on growth performance and the onset of laying in hens. One hundred and fifteen 3-week-old chickens were divided into four treatment groups of 39, 33, 31 and 12 chickens. They were placed on four dietary treatments consisting of 0 p.p.m. CCC (control), 5 p.p.m. CCC from 14 weeks of age (5 p.p.m. A), 5 p.p.m. CCC from the beginning (5 p.p.m. B), and 50 p.p.m. CCC from the beginning (50 p.p.m. B). The basal diets were formulated according to the growing period and were iso-nitrogenous and iso-energetic. The crude protein content was 17.99% dry matter and 14.63% dry matter during the first 3-8 weeks and 9-20 weeks, respectively. The energy content was 12.7 and 12.75 MJ metabolisable energy (ME)/kg dry matter for the respective two growth phases. Feed intake, bodyweight changes and egg production were measured. Blood samples for oestrogen determination were collected weekly from the 15th week until the first egg was laid. Depressive effects of 50 p.p.m. CCC on bodyweight gain during weeks 3-8 and feed efficiency over the whole period were observed. There were no treatment differences (p > 0.05) on feed intake, bodyweight gain during weeks 9-20 and age at the point of lay. CCC inclusion at 50 p.p.m. significantly (p < 0.05) stimulated the oestrogen concentration at 17 and 18 weeks of age, and was 65% higher than the control at 18 weeks.

Age Factors↗
PubMed2002

Distribution of 15N-chlorocholine chloride in eggs of laying hens.

The distribution of Chlorocholine chloride (CCC) in the eggs of laying hens was studied using 15N-CCC. Twelve layers (37 weeks old) were divided into four groups and used in this study consisting of three feeding phases. In phase one (7 days), all the hens received a CCC-free diet [165 g CP/kg dry matter (DM); 11.58 MJ ME/kg DM]. In phase two (11 days), four levels of 15N-CCC: 0, 5, 50 and 250 ppm were added to the respective diets, while in phase three (7 days), CCC-free feed was again offered. Egg samples were taken and the 15N content of egg yolk and albumin were determined. At the end of phase two, there was a significant (p < 0.05) increase in 15N content in egg yolk from hens fed the 50 and 250 ppm CCC diets and in albumin from hens fed the 250 ppm CCC diet. The estimated 15N-CCC residue was 1.71, 6.64, 28.80 ppm in egg yolk and 1.58, 1.08 and 4.50 ppm in albumin from hens fed 5, 50 and 250 ppm CCC, respectively. The CCC residue, from quantitative analysis ranged from 0.21 to 0.93 and 0.93 to 2.43 ppm in yolk of hens fed 50 and 250 ppm CCC, respectively, whereas a range of 0.40-1.46 ppm, was found in the albumin of hens fed 250 ppm. The difference in measured CCC in yolk and albumin and that estimated from 15N-CCC could have been due to breakdown products of 15N-CCC. Seven days after withdrawal of 15N-CCC, the estimated 15N-CCC residue in egg yolk decreased to 0.43, 2.45 and 15.59 ppm, on 5, 50 and 250 ppm CCC dietary treatments, respectively, and to 2.46 ppm in albumin from hens fed 250 ppm CCC. The higher increase in 15N content could have been due to a higher incorporation of 15N-CCC into yolk than albumin during the process of rapid yolk deposition. This experiment showed that consumed CCC is distributed both into yolk and albumin in a dose dependent manner and that CCC is metabolized in laying hens. However, the level of CCC in the diet which could lead to accumulation of detectable CCC levels in eggs as observed in this study, is much higher than the established maximum residual limits in grains.

Animals↗
PubMed2005

Gibberellins are involved in nodulation of Sesbania rostrata.

Upon submergence, Azorhizobium caulinodans infects the semiaquatic legume Sesbania rostrata via the intercellular crack entry process, resulting in lateral root-based nodules. A gene encoding a gibberellin (GA) 20-oxidase, SrGA20ox1, involved in GA biosynthesis, was transiently up-regulated during lateral root base nodulation. Two SrGA20ox1 expression patterns were identified, one related to intercellular infection and a second observed in nodule meristem descendants. The infection-related expression pattern depended on bacterially produced nodulation (Nod) factors. Pharmacological studies demonstrated that GAs were involved in infection pocket and infection thread formation, two Nod factor-dependent events that initiate lateral root base nodulation, and that they were also needed for nodule primordium development. Moreover, GAs inhibited the root hair curling process. These results show that GAs are Nod factor downstream signals for nodulation in hydroponic growth.

Azorhizobium caulinodans↗
PubMed2006

The metabolite products of chlorocholine chloride (CCC) in eggs and meat of laying hens fed 15N-CCC containing diets.

An experiment was conducted to evaluate the metabolic products of chlorocholine chloride (CCC) in eggs and meat of laying hens fed a diet containing (15)N-CCC. Ten brown laying hens were randomly divided into two groups of five each. One group was offered (15)N-CCC free diet while the other group received a diet with 100 ppm (15)N-CCC for 11 days. Samples of eggs and meat from the laying hens were collected. Egg yolks and albumen were separated. Meat was collected from the breast and femur. The metabolic products of CCC were measured using ion trap electrospray ionisation mass spectrometry (ion trap-ESI-MS/MS). Determination of CCC or its metabolites in eggs and meat showed that CCC was metabolised to choline. Corresponding MS/MS spectra were obtained for m/z 104 (choline) or 105 ((15)N-choline), whereas nothing was detected at m/z 122 (CCC) or 123 ((15)N-CCC). The results from this study indicate that CCC will be metabolised in tissues of laying hens.

Animals↗