Growth-regulating properties of picloram, 4-amino-3,5,6-trichloropicolinic acid

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.

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.


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.


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.


2018 ◽  
Vol 51 (4) ◽  
pp. 60-72
Author(s):  
E.K. Eifediyi ◽  
F.O. Ogedegbe ◽  
N.B. Izuogu ◽  
C.A. Adedokun ◽  
A. Katibi ◽  
...  

Abstract The Guinea savannah zone of Nigeria is beset by increasing population and infrastructural development, thereby putting pressure on available land with rapidly declining fertility due to low organic matter content, soil erosion, high temperature and seasonal bush burning. Sesame is cultivated in this zone and the yield has remained very low, compared to yield in other parts of the world. This could be attributed to poor nutrient status and poor cultural practices used by peasant farmers. A field experiment was conducted at the Teaching and Research Farm, University of Ilorin, Nigeria, in a southern Guinea savannah zone in 2015 and repeated in 2016 cropping season to determine the effects of 2,4-Dichlorophenoxyacetic acid (2,4-D), a plant growth regulator and NPK fertilizer on the growth and yield of sesame. The experiment was laid out as a factorial arrangement, fitted into a randomized complete block design replicated thrice. The factors imposed were 2,4-D (0, 5 and 10 ppm ha−1) and NPK 15:15:15 (0, 100, 200 and 300 kg ha−1). Data were collected on vegetative traits (plant height, number of leaves, leaf area) and yield components (number of capsules per plant; yield per plant and per hectare). The data were subjected to analysis of variance (ANOVA) using the Genstat statistical package 17th edition and significant means were separated by using the least significant difference at 5% level of probability. The result revealed that using plant growth regulator and NPK fertilizer had significant effects (p<0.05) on plant height (151 cm) and yield per hectare (530 kg/ha). The qualitative and quantitative analysis of the seeds further reaffirmed the presence of bioactive compounds, such as saponins, tannins, flavonoids and phenolic compounds, which are important health promoting food in the seeds.


Author(s):  
Sri Kasmiyati ◽  
Elizabeth Betty Elok Kristiani ◽  
Maria Marina Herawati

Artemisia cina is one of a member of genus Artemisia that has potential as a medicinal plant. However, the levels of Artemisia medicinal bioactive compounds are very low. Polyploidization is an alternative method that can enhance of growth and secondary metabolite productions of plants. The aims of this research were to determine the effect of polyploid induction using colchicine and plant growth regulator toward plant growth, the chlorophyll, kaemferol and quercetin contents of A. cina. Four different A. cina used in this research consisted of two diploid genotypes (TWN and KJT) and two polyploid genotypes (J and M). Induction of mutant polyploid was conducted using colchicine and combination of plant growth regulator benziladenyl (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D). The measured plant growth parameters were dry weight, leaf area, and plant height. The chlorophyll content of leaves was determined spectrophotometrically, and flavonoid content determined using HPLC. The result showed that the polyploid genotype (M) significantly decreased leaf and root growth compared to the KJT and TWN. In A. cina plants, polyploidization using colchicine is more effective in increasing the biomass than using combination plant growth regulator BA and 2,4-D. The flavonoid content of KJT was the lowest, and significantly different compared to the other plants. This study provides new information about the effect of polyploid on growth and flavonoid content in A. cina. This can be  useful information to develop A. cina to become a medicinal plant.


1957 ◽  
Vol 10 (1) ◽  
pp. 80 ◽  
Author(s):  
NP Kefford ◽  
Judith M Kelso

The thionaphthen�2�, �3-, -5-, -6�, and -7-acetic acids have been synthesized from the chlorides of the corresponding carboxylic acids by the Arndt-Eistert reaction and their plant growth-regulating activities, as indicated by their effects upon protoplasmic streaming, have been compared with those of indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4�D). The thionaphthen-3- and -7- acetic acids and IAA have similar effects upon protoplasmic streaming, while the effects of the thionaphthen-2-, -5-, and �6-acetic acids differ from those of IAA and resemble in part those of 2, 4-D.


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