scholarly journals Short-Term Growth Response to Growth Regulators In Roots of Zea Mays

1968 ◽  
Vol 21 (2) ◽  
pp. 201 ◽  
Author(s):  
DE Bottrill ◽  
JB Hanson

A study was made of the inhibition of root growth in Z. mays by 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,6-trichlorophenoxyacetic acid (2,4,6�T), and indole-3-acetic acid (IAA) over a wide range of concentrations. IAA and 2,4�D caused identical responses whereas the response to 2,4,6-T was different. Application of 2,4.D or IAA at concentrations of 4�5xl0-4M for 5 min resulted in an immediate reversible inhibition of root growth whereas long-term application gave an irreversible inhibition. The same concentration of 2,4,6-T caused a similar degree of inhibition of root growth, but only after an extended treatment, and the roots could then recover from the inhibition in the presence of the chemical.

2015 ◽  
Vol 44 (1) ◽  
pp. 123-132
Author(s):  
J. Zakrzewski

Growth response of <i>Pinus silvestris</i> hypocotyl sections to some synthetic growth regulators and related substances was studied. Elongation of hypocotyl sections was stimulated by naphtaleneacetic acid, indole-3-acetic acid, in-dole-3-propionic acid, indole-3-butyric acid, 2,4-dichlorophenoxyacetic acid, indoleaoetic amide, indoleacetic nitrile and coumarin. Indole-3-acetic acid and naphtaleneacetic acid extended period of growth up to 16 and 24 hours, respectively. Growth was inhibited by kinetin, trans-cinnamic acid and 2,3,5-tri-iodobenzoic acid. No effect of gibberellic acid, tryptophan and biotin was observed.


1971 ◽  
Vol 49 (6) ◽  
pp. 889-897 ◽  
Author(s):  
W. R. Eisinger ◽  
D. J. Morré

Picloram, 2,4-D (2,4-dichlorophenoxyacetic acid) and IAA (indole-3-acetic acid) cause similar stimulations of polarized cell elongation in stem and coleoptile sections floated on solutions containing the growth regulator. Picloram, like 2,4-D and IAA, supports growth of tissue explants in culture, inhibits root growth, induces cell wall loosening, produces stem curvature and other formative effects, promotes loss of chlorophyll, and regulates abscission and rooting responses. A kinetic analysis of root growth inhibition indicates a common mode of action for picloram and 2,4-D. Picloram meets the minimal structural requirements for auxin activity. The greater herbicidal effectiveness of picloram is attributed to increased mobility and resistance to breakdown within the plant. The ability of picloram to increase markedly the growth of intact shoot cuttings is not shared by either 2,4-D or IAA and neither picloram nor 2,4-D are readily transported in a polar manner in the Avena curvature test. We conclude that picloram functions as a growth regulator of the auxin type with a herbicidal action similar to that of 2,4-D.


Author(s):  
Vidhi Shah

Abstract: This research was conducted to gather data and understand the perception what the Indian population holds when it comes to investing in cryptocurrency. To do so, a survey was designed using the UTAUT model and was circulated by the means of google forms. A wide range of parameters were considered to avail the maximum possible accuracy for the data collected. Parameters like, the ease of investing crypto, short term and long term benefits, monetary benefits, social benefits were considered. All of these parameters were supposed to be answered on a scale of 5. After collecting all the data, the results were analyzed and evaluated using which the hypothesis made were proved. Keywords: Cryptocurrency, UTAUT, performance expectancy, effort expectancy, perceived monetary benefits, perceived safety, social influence, adoption intension.


1996 ◽  
Vol 39 (2) ◽  
Author(s):  
G. Asch ◽  
K. Wylegalla ◽  
M. Hellweg ◽  
D. Seidl ◽  
H. Rademacher

During the Proyecto de Investigaciòn Sismològica de la Cordillera Occidental (PISCO '94) in the Atacama desert of Northern Chile, a continuously recording broadband seismic station was installed to the NW of the currently active volcano, Lascar. For the month of April, 1994, an additional network of three, short period, three-component stations was deployed around the volcano to help discriminate its seismic signals from other local seismicity. During the deployment, the volcanic activity at Lascar appeared to be limited mainly to the emission of steam and SO2. Tremor from Lascar is a random, «rapid-fire» series of events with a wide range of amplitudes and a quasi-fractal structure. The tremor is generated by an ensemble of independent elementary sources clustered in the volcanic edifice. In the short-term, the excitation of the sources fluctuates strongly, while the long-term power spectrum is very stationary.


Author(s):  
Alex G. Alexander

Indole-3-acetic acid, 2,4-dichlorophenoxyacetic acid, and maleic hydrazide were applied as foliar sprays to 10-week-old sugarcane plants during initial studies of the interrelationships of growth-regulating materials with the sugar-metabolizing enzymes of sugarcane. Leaf samples were harvested at 1, 3, 9, and 27 days following treatment for sugar and enzyme assays. Sugar analyses were run for total ketoses, sucrose, fructose, and total reducing sugars, with glucose being determined by calculation. A series of acid phosphatase assays were conducted using as substrates the following compounds: ß-glycerophosphate, adenosinetriphosphate, uridine diphosphate glucose, glucose-1-phosphate, glucose-6-phosphate, fructose-6- phosphate, fructose-1,6-diphosphate, and 3-phosphoglyceric acid. Additional enzymes included invertase, amylase, hexokinase, phosphohexose isomerase, aldolase, triosephosphate dehydrogenase, phosphoglyceryl kinase, condensing enzyme, isocitric acid dehydrogenase, transaminase, peroxidase, and glucose oxidase. All enzyme preparations consisted of dialyzed water-soluble protein extracted from freeze-dried leaf tissue and precipitated with ammonium sulfate between 35 and 95 percent of saturation.


2020 ◽  
Vol 12 (3) ◽  
pp. 673-682
Author(s):  
Yasmina BENABDESSLEM ◽  
Kadda HACHEM ◽  
Samia GHOMARI

The chickpea (Cicer arietinum) is one of the leguminous species most appreciated by consumers in the Mediterranean basin, while being an important source of protein. Nevertheless, its crop yields are greatly limited by several biotic and abiotic stresses, the main one being Ascochyta rabiei, the causal agent of anthracnose. As traditional breeding methods have proved to be ineffective in controlling this pathogen, resorting to biotechnological methods is necessary. Therefore, in this study, the callogenic capacity of stem and leaflet explants from three genotypes of chickpea, namely ‘FLIP 84-92 C’, ‘ILC 32-97’, and ‘ILC 263’, cultured on Murashige and Skoog (MS) medium with different hormonal balances of auxins (indole-3-acetic acid [IAA] and 2,4-dichlorophenoxyacetic acid [2,4-D]) and cytokinin (kinetin), was determined. For all the genotypes, high percentages of callogenesis were recorded in the different explants grown on an MS medium with 2 mg of both IAA and kinetin. Then, a patho-system of Cicer arietinum calluses with Ascochyta rabiei was investigated, followed by a histological assessment of this interaction. The presence of the fruiting bodies of the pathogen was revealed in the calluses of the ‘ILC 32-97’ and ‘ILC 263’ genotypes. Notably, the latter showed a high sensitivity to the pathogen, as indicated by an abundance of pycnidia in its tissues. As for the ‘FLIP 84-92 C’ genotype, the histological sections showed a total absence of inter- and intracellular fruiting bodies of the pathogen in the callus tissues. Therefore, this genotype was considered as resistant to Ascochyta rabiei.


Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 435 ◽  
Author(s):  
Marek Sustr ◽  
Ales Soukup ◽  
Edita Tylova

Potassium is an essential macronutrient that has been partly overshadowed in root science by nitrogen and phosphorus. The current boom in potassium-related studies coincides with an emerging awareness of its importance in plant growth, metabolic functions, stress tolerance, and efficient agriculture. In this review, we summarized recent progress in understanding the role of K+ in root growth, development of root system architecture, cellular functions, and specific plant responses to K+ shortage. K+ transport is crucial for its physiological role. A wide range of K+ transport proteins has developed during evolution and acquired specific functions in plants. There is evidence linking K+ transport with cell expansion, membrane trafficking, auxin homeostasis, cell signaling, and phloem transport. This places K+ among important general regulatory factors of root growth. K+ is a rather mobile element in soil, so the absence of systemic and localized root growth response has been accepted. However, recent research confirms both systemic and localized growth response in Arabidopsis thaliana and highlights K+ uptake as a crucial mechanism for plant stress response. K+-related regulatory mechanisms, K+ transporters, K+ acquisition efficiency, and phenotyping for selection of K+ efficient plants/cultivars are highlighted in this review.


2017 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Wang Yue ◽  
Sun Fulai ◽  
Gao Qingrong ◽  
Zhang Yanxia ◽  
Wang Nan ◽  
...  

Branched spike wheat is a hexaploid germplasm with branched rachis on its main rachises, and the crucial period for branched rachises occurrence and development is just after the two ridges stage of shoot apex. Natural [indole-3-acetic acid (IAA), indole-3butyric acid (IBA)] and synthetic [(1-naphthaleneacetic acid (NAA), 2,4-Dichlorophenoxyacetic acid (2,4-D)] auxins were applied at this period to investigate the spike traits, seedling growth and photosynthesis related characters and expression of a putative homologue of the LEAFY in branched spike wheat. The four types of experienced auxins induced similar effects on these foresaid characters, although the impact extents were different among the auxins treatments. More branched rachis, spikelets, fertile florets and longer branched rachis were obtained in plants with IAA and IBA at 0.1 mM or NAA and 2,4-D at 1.0mM than those plants with no auxin treated. Auxin treatments also increased fresh and dry mass, photosynthetic pigment and parameters. TFL, a LEAFY-like gene was cloned in branched spike wheat and TFL mRNA expression was quantified using real-time reverse transcriptase-PCR. Application of the auxins accelerated the rise in TFL expression during the periods of branched rachises occurrence and extension. The data supports the hypothesis that auxins play a central role in the regulation branched spike development and TFL might correlate with the development of branched rachises in branched spike wheat.


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