scholarly journals Evaluation of Engulfreg; adjuvant with nitrogen for breaking dormancy in blackcurrant (Ribes nigrum)

2014 ◽  
Vol 67 ◽  
pp. 314-319
Author(s):  
J.T. Smith ◽  
G.B. Follas

During the 2013 spring two different nitrogen sources (calcium nitrate and BreakNtrade;) were applied using a motorised knapsack sprayer to dormant blackcurrants with and without the addition of a super penetrant surfactant (Engulfreg;) for dormancy breaking Trials were conducted in Nelson at two grower sites consisting of Ben Ard and Magnus blackcurrant varieties Bud break and flowering was advanced by 510 days with the combination of the super penetrant surfactant and either nitrogen source A Nitrogen source applied alone did not influence bud break or flowering The length of flowering was condensed on Magnus and a more even and earlier fruit maturity occurred on both varieties with the combination of the super penetrant surfactant and nitrogen The importance of these findings for the blackcurrant industry is discussed

Author(s):  
Mostafa M. Rady ◽  
Mohamed A. Seif El-Yazal

The Environmental and climatic conditions affect the flower bud growth, flowering and yield performance of fruit species. Temperature appears to be important factors for temperate fruit trees in mild climates. The relationships between breaking bud dormancy and climatic influences on flowering, growth and metabolic changes in contents of biogenic amines (spermine, spermidine, putrescine, cadaverine and phenylethylamine), arginine and anthocyanin before and after bud break were evaluated for "Ain Shemer" apple (Malus sylvestris, Mill) trees under exogenously applied hydrogen cyanamide (dormex), calcium nitrate Ca(NO3)2 and thiourea. The studies have shown that breaking bud dormancy (as early date of bud break and percentage of bud break) by the above dormancy breaking agents were correlated with the high content of biogenic amines and arginine in buds. Seasonal variations in biogenic amines, arginine and anthocyanin level were present in buds during the research period (dormancy and dormancy release period). Levels of spermine, spermidine, putrescine, cadaverine, phenylethylamine, arginine and anthocyanin have simultaneously risen with bud burst and new growth. The most abundant polyamines in buds were cadaverine followed by spermine. The best results were obtained with Dormex after exposure the trees to about 274 natural chilling hours ? +7.2oC; therefore, we recommend using this compound to achieve bud break as early as possible in "Ain Shemer" apple variety by regulating the contents of biogenic amines and arginine in buds and subsequently the high percentages of bud break and maximum yield.


Synthesis ◽  
2021 ◽  
Author(s):  
Xinjun Luan ◽  
Jingxun Yu

AbstractTransition-metal-catalyzed C–N bond formation is one of the most important pathways to synthesize N-heterocycles. Hydroxylamines can be transformed into a nucleophilic reagent to react with a carbon cation or coordinate with a transition metal; it can also become an electrophilic nitrogen source to react with arenes, alkenes, and alkynes. In this short review, the progress made on transition-metal-catalyzed cycloadditions with hydroxylamines as a nitrogen source is summarized.1 Introduction2 Cycloaddition To Form Aziridine Derivatives2.1 Intramolecular Cycloaddition To Form Aziridine Derivatives2.2 Intermolecular Cycloaddition To Form Aziridine Derivatives3 Cycloaddition To Form Indole Derivatives4 Cycloaddition To Form Other N-Heterocycles4.1 Aza-Heck-Type Amination Reactions4.2 Nitrene Insertion Amination Reactions4.3 Intramolecular Nucleophilic and Electrophilic Amination Reactions5 Conclusion and Outlook


1975 ◽  
Vol 28 (3) ◽  
pp. 301 ◽  
Author(s):  
MJ Hynes

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.


2001 ◽  
Vol 67 (4) ◽  
pp. 1839-1845 ◽  
Author(s):  
Martin L. Saker ◽  
Brett A. Neilan

ABSTRACT The potentially toxic freshwater cyanobacteriumCylindrospermopsis raciborskii has become increasingly prevalent in tropical and temperate water bodies worldwide. This paper investigates the effects of different nitrogen sources (NO3 −, NH4 +, and omission of a fixed form of nitrogen) on the growth rates, morphologies, and cylindrospermopsin (CYL) concentrations (expressed as a percentage of the freeze-dried weight) of seven C. raciborskii isolates obtained from a range of water bodies in northern Australia and grown in batch culture. In general, growth rates were lowest in the absence of a fixed-nitrogen source and highest with NH4 + as the nitrogen source. Conversely, the highest concentrations of CYL were recorded in cultures grown in the absence of a fixed-nitrogen source and the lowest were found in cultures supplied with NH4 +. Cultures supplied with NO3 − were intermediate with respect to both CYL concentration and growth rate. Different nitrogen sources resulted in significant differences in the morphology of C. raciborskii trichomes. Most notable were the loss of heterocysts and the tapering of end cells in cultures supplied with NH4 + and the statistically significant increase in vegetative cell length (nitrogen depleted < NO3 − < NH4 +). The morphological changes induced by different nitrogen sources were consistent for all isolates, despite measurable differences in vegetative-cell and heterocyst dimensions among isolates. Such induced morphological variation has implications forCylindrospermopsis taxonomy, given that distinctions between species are based on minor and overlapping differences in cell lengths and widths. The close phylogenetic association among all seven isolates was confirmed by the high level (>99.8%) of similarity of their 16S rRNA gene sequences. Another genetic technique, analysis of the HIP1 octameric-palindrome repeated sequence, showed greater heterogeneity among the isolates and appears to be a useful method for distinguishing among isolates of C. raciborskii.


2003 ◽  
Vol 83 (4) ◽  
pp. 729-735 ◽  
Author(s):  
M. A. Matus-Cádiz ◽  
P. Hucl

An effective dormancy-breaking method may be of interest to wheat (Triticum aestivum L.) breeders selecting for increased seed dormancy prior to advancing their populations in greenhouse grow-outs. The objective of this study was to identify an effective pre-treatment for breaking dormancy in wheat that did not result in seedling etiolation. In 2000, eight dormant (W98616, line 211, EMDR-4, EMDR-9, EMDR-14, RL4137, Columbus, and AC Domain) and one nondormant line (Roblin) were grown at two locations in Saskatchewan. Seeds were: (i) stored for zero to 21 wks at 24°C before incubating at 20°C for 7 d; (ii) incubated at 5, 10, 15, 20, and 25°C for 14 d; and (iii) treated with gibberellic acid (GA3) (0.0006 and 0.0014 M), potassium nitrate (KNO3) (0.01 and 0.02 M), chilling, heating, chilling with 0.01 M KNO3, and heating with 0.01 M KNO3 before incubating at 10°C for 14 d. Seedling growth was observed in a duplicated growth chamber experiment. Seedling length, first inter-node length, and biomass yield data were collected from plants grown from seeds treated with four effective pretreatments. Data were subjected to an ANOVA. Six to 18 weeks of storage at 24°C were required to break the dormancy (≥ 95% germination) in dormant genotypes. Incubation at 10°C was the most effective temperature for promoting germination in dormant seeds after 10d of testing. Four pre-treatments including 0.0006 M GA3, 0.0014 M GA3, chilling with 0.01 M KNO3, and heating with 0.01 M KNO3 led to ≥ 95% germination within 10 d of testing. Only GA3 treatments were associated with etiolated seedling growth. Heating with 0.01 M KNO3 or chilling with 0.01 M KNO3, applied before incubating at 10°C in darkness, may be of interest to breeders selecting for increased dormancy before advancing breeding populations in greenhouse grow-outs. Key words: Triticum, dormancy, nitrate, chilling, heating, etiolated seedling


1975 ◽  
Vol 25 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Meryl Polkinghorne ◽  
M. J. Hynes

SUMMARYWild-type strains ofAspergillus nidulansgrow poorly onL-histidine as a sole nitrogen source. The synthesis of the enzyme histidase (EC. 4.3.1.3) appears to be a limiting factor in the growth of the wild type, as strains carrying the mutantareA102 allele have elevated histidase levels and grow strongly on histidine as a sole nitrogen source.L-Histidine is an extremely weak sole carbon source for all strains.Ammonium repression has an important role in the regulation of histidase synthesis and the relief of ammonium repression is dependent on the availability of a good carbon source. The level of histidase synthesis does not respond to the addition of exogenous substrate.Mutants carrying lesions in thesarA orsarB loci (suppressor ofareA102) have been isolated. The growth properties of these mutants on histidine as a sole nitrogen source correlate with the levels of histidase synthesized. Mutation at thesarA andsarB loci also reduces the utilization of a number of other nitrogen sources. The data suggest that these two genes may code for regulatory products involved in nitrogen catabolism. No histidase structural gene mutants were identified and possible explanations of this are discussed.


1979 ◽  
Vol 9 (4) ◽  
pp. 514-516 ◽  
Author(s):  
L. R. Auchmoody

Nitrogen fertilizers triggered germination of dormant Prunuspensylvanica L. seed naturally buried in the forest floor of 60-year-old Allegheny hardwood stands. Neither triple superphosphate nor muriate of potash applied with urea increased germination over that which occurred with urea alone. Rates as low as 56 kg/ha N from urea and calcium nitrate and 112 kg/ha N from ammonium sulfate stimulated germination. Nitrate was apparently responsible for breaking dormancy.


2015 ◽  
Vol 77 (31) ◽  
Author(s):  
Huszalina Hussin ◽  
Madihah Md Salleh ◽  
Chong Chun Siong ◽  
Muhammad Abu Naser ◽  
Suraini Abd- Aziz ◽  
...  

The recent study has demonstrated the effects of different nitrogen sources on vanillin production by Phanerochaete chrysosporium. Primary screening supported maximum biotransformation of ferulic acid (from lemongrass leaves hydrolysate) to vanillin by using ammonium chloride and yeast extract as inorganic and organic nitrogen source, respectively. With the 2-level factorial analysis, the optimum conditions of vanillin production from ferulic acid by P. chrysosporium was achieved at 0.192g/L with a molar yield of 24.5%.


2015 ◽  
Vol 197 (17) ◽  
pp. 2831-2839 ◽  
Author(s):  
Katherine A. Miller ◽  
Robert S. Phillips ◽  
Paul B. Kilgore ◽  
Grady L. Smith ◽  
Timothy R. Hoover

ABSTRACTSalmonella entericserovar Typhimurium, a major cause of food-borne illness, is capable of using a variety of carbon and nitrogen sources. Fructoselysine and glucoselysine are Maillard reaction products formed by the reaction of glucose or fructose, respectively, with the ε-amine group of lysine. We report here thatS. Typhimurium utilizes fructoselysine and glucoselysine as carbon and nitrogen sources via a mannose family phosphotransferase (PTS) encoded bygfrABCD(glucoselysine/fructoselysine PTS components EIIA, EIIB, EIIC, and EIID; locus numbers STM14_5449 to STM14_5454 inS. Typhimurium 14028s). Genes coding for two predicted deglycases within thegfroperon,gfrEandgfrF, were required for growth with glucoselysine and fructoselysine, respectively. GfrF demonstrated fructoselysine-6-phosphate deglycase activity in a coupled enzyme assay. The biochemical and genetic analyses were consistent with a pathway in which fructoselysine and glucoselysine are phosphorylated at the C-6 position of the sugar by the GfrABCD PTS as they are transported across the membrane. The resulting fructoselysine-6-phosphate and glucoselysine-6-phosphate subsequently are cleaved by GfrF and GfrE to form lysine and glucose-6-phosphate or fructose-6-phosphate. Interestingly, althoughS. Typhimurium can use lysine derived from fructoselysine or glucoselysine as a sole nitrogen source, it cannot use exogenous lysine as a nitrogen source to support growth. Expression ofgfrABCDEFwas dependent on the alternative sigma factor RpoN (σ54) and an RpoN-dependent LevR-like activator, which we designated GfrR.IMPORTANCESalmonellaphysiology has been studied intensively, but there is much we do not know regarding the repertoire of nutrients these bacteria are able to use for growth. This study shows that a previously uncharacterized PTS and associated enzymes function together to transport and catabolize fructoselysine and glucoselysine. Knowledge of the range of nutrients thatSalmonellautilizes is important, as it could lead to the development of new strategies for reducing the load ofSalmonellain food animals, thereby mitigating its entry into the human food supply.


2019 ◽  
Vol 4 (1) ◽  
pp. 33-44 ◽  
Author(s):  
S. N. Zheleznova

The diatom Cylindrotheca closterium (Ehrenberg) Reimann et Levin is characterized by high productivity (up to 1.5 g·l-1·day-1) and the ability to accumulate a valuable carotenoid fucoxanthin (up to 2 % of dry weight). In the development of biotechnology based on microalgae, the key issue is the creation of concentrated nutrient medium. Nitrogen is one of the most important components in the nutrient medium that significantly affects the production characteristics of all microalgae. The aim of this study is to compare the production characteristics of C. closterium in an intensive storage culture using different forms of nitrogen in the medium. In the first experiment, nitrate and sodium nitrite, urea, and nitrogen in the form of ammonium were used as a source of nitrogen. The amount of nitrates, nitrites, ammonium, and urea in the medium was calculated from the nitrogen content of the RS nutrient medium, with a nitrogen to phosphorus ratio of 15 : 1. In the second experiment, amino acids were used as a nitrogen source – arginine, asparagine, cysteine. The possibility of using the microalgae C. closterium for the growth of various organic sources of nitrogen (urea, cysteine, asparagine) was shown. Productive characteristics in the intensive storage culture of C. closterium using urea, cysteine, and asparagine as the sole source of nitrogen in the RS nutrient medium were determined. It is shown that when urea was used, the productivity reached its maximum values and amounted to 1.5 g·l-1·day-1. Thus, the expediency of using urea in the medium for obtaining the maximum yield of biomass was shown. The use of cysteine in the stationary phase of growth to achieve a long stationary phase with minimal concentrations of the nitrogen source in the nutrient medium is also advisable. It was found that C. closterium was able to grow and vegetate at sufficiently high concentrations of nitrite, and the addition of nitrogen in ammonium form to the nutrient medium during the active growth of C. closterium led to inhibition of all metabolic processes and to the death of the culture.


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