Action Of Plant Growth Regulators Research Articles

Plant growth regulators and mobilization of reserves in imbibition phases of yellow passion fruit.

The production of seedlings of the passion fruit tree, usually, is sexual, and the seeds are not uniform in the seedling emergence, and soaking treatments of seeds can provide faster and more uniform germination. It was aimed to study the action of plant growth regulators and the mobilization of reserves in the stages of soaking of yellow passion fruit seeds. The seeds were soaked for five hours in solutions containing plant growth regulators, in a completely randomized design, in a factorial 8 x 4, with four replications. The first factor corresponds to eight plant growth regulators: T1 - distilled water (control); T2 - 6-benzylaminepurine ​​500 mg L-1; T3 - 4-(3-indolyl) butyric acid 500 mg L-1; T4 - gibberellic acid 500 mg L-1; T5 - spermine 250 mg L-1; T6 - spermine 750 mg L-1; T7 - spermidine 750 mg L-1; T8 - spermidine 1250 mg L-1; and the second factor, to the four soaking times: zero, four, 72 and 120 hours, corresponding, respectively, to the dry seed, and to phases I, II, and III of the imbibition curve. It was evaluated the biochemical composition of seeds (lipids, soluble sugars and starch). The seeds showed accumulation of lipids in phase III; the content of soluble sugars increased in phase I and decreased in phase II. The starch content increased until the phase II and decreased in phase III. Starch is the main reserve in the seeds and the main source of energy used in phase III; soaking the seeds in polyamines generates an accumulation of lipids in the seeds and soaking in plant growth regulators increases the burning of starch.

CONTENT AND RATIO OF PHOTOSYNTHETIC PIGMENTS IN STIPULES OF WINTER PEA WITH USING DIFFERENT GROWING TECHNOLOGIES

The article describes the results of research on the content and ratio of photosynthetic pigments in the stipules of winter peas using different cultivation technologies. The objects of the study were winter pea plants (Pisum sativum L.) of variety NS Moroz, plant growth regulator (PGR) Endofit L1 RK, bacterial preparation Bioinoculant BTU-r, microfertilizers «LF-Bobovi» and Biobor 140. The purpose of our research was to study the formation of photosynthetic pigments of winter pea plants under the action of growth regulator Endophyte L1 RK, bacterial preparation Bioinoculant BTU-r, their complex applying and foliar treatment systems with microfertilizers «LF- Bobovi» and Biobor 140. Analysis of chlorophyll and carotenoid content in alcohol extract (96.0%) was performed using a spectrophotometer Ulab − 102UV (China) at different values of wavelength: λ = 441; λ = 649; λ = 665. The volume of the working solution was 25 ml. Calculations of these indexes were performed according to the formulas of H. K. Lichtenthaler. During the study period, the influence of plant growth regulator, bacterial preparation, and foliar fertilization on the content of chlorophyll a and b, their sum, and concentration of carotenoids in the stipules of winter pea plants were evaluated. The research results indicate the dependence of these indicators on the use of the growth regulator and the bacterial drug, as well as on foliar fertilization. It was found that the implementation of foliar treatment in the phase of 3-5 stipules and complex use (in phases 3-5 of stipules and buttons) phase with tank mixtures of micro fertilizers «LF- Bobovi» (1.5 l / ha and 2.5 l / ha) and Biobor 140 (1.0 l / ha) led to an increase of the content of chlorophyll a and b, their total amount and carotenoid content. The highest content of chlorophylls a and b, their sum, and carotenoids in the stipules of winter pea plants were in the variant with the combined use of pre-sowing seed treatment with growth regulator Endophyte L1 RK (0.01 l / t), bacterial preparation Bioinoculant BTU-r (2 l / t) and at foliar treatment with microfertilizers «LF- Bobovi» (1.5 l / ha and 2.5 l / ha) and Biobor 140 (1.0 l / ha).The search for ways and opportunities to increase the grain yield of winter pea varieties Moroz due to the introduction of new technological methods of its cultivation remains relevant. A possible solution to the problem of improving the productivity of winter peas is the use of different mechanisms of action of plant growth regulators, inoculation with symbiotic microorganisms, and foliar feeding with tank mixtures of chelated microfertilizers.

Induction of Somatic Embryogenesis in Tamarillo (Solanum betaceum Cav.) Involves Increases in the Endogenous Auxin Indole-3-Acetic Acid.

Somatic embryogenesis (SE) is a complex biological process regulated by several factors, such as the action of plant growth regulators, namely auxins, of which the most physiologically relevant is indole-3-acetic acid (IAA). In tamarillo, an optimized system for induction of SE creates, after an induction process, embryogenic (EC) and non-embryogenic callus (NEC). In this work the endogenous levels of auxin along the induction phase and in the calli samples were investigated using chemical quantifications by colorimetric reactions and HPLC as well as immunohistochemistry approaches. Differential gene expression (IAA 11, IAA 14, IAA 17, TIR 1, and AFB3) analysis during the induction phase was also carried out. The results showed that the endogenous IAA content is considerably higher in embryogenic than in non-embryogenic calli, with a tendency to increase as the dedifferentiation of the original explant (leaf segments) evolves. Furthermore, the degradation rates of IAA seem to be related to these levels, as non-embryogenic tissue presents a higher degradation rate. The immunohistochemical results support the quantifications made, with higher observable labeling on embryogenic tissue that tends to increase along the induction phase. Differential gene expression also suggests a distinct molecular response between EC and NEC.

Waterlogging Stress Physiology in Barley

Barley (Hordeum vulgare L.) is the most susceptible cereal species to excess moisture stress. Waterlogging-induced hypoxia causes major morphological, physiological, and metabolic changes, some of which are regulated by the action of plant growth regulators and signal molecules including nitric oxide. Recent studies have evidenced the participation of phytoglobins in attenuating hypoxic stress during conditions of excessive moisture through their ability to scavenge nitric oxide and influence the synthesis and response of growth regulators. This review will highlight major cellular changes linked to plant responses to waterlogging stress with emphasis on phytoglobins.

UPLC-MS-Based Non-targeted Analysis of Endogenous Metabolite Changes in the Leaves of Scabiosa tschiliensis Grüning Induced by 6-Benzylaminopurine and Kinetin.

In vitro propagation technology with plant growth regulators (PGRs) is generally applied in the cultivation of Scabiosa tschiliensis, which can solve collection difficulties and limited resources of S. tschiliensis. Nevertheless, comprehensive metabolomic evaluation on S. tschiliensis with PGR effects is still lacking. In this work, a non-targeted metabolomics approach, coupled with statistical and pathway enrichment analysis, was used to assess the regulatory influences of 6-benzylaminopurine (6-BA) and kinetin (KT) applied in S. tschiliensis. The results showed that the PGRs affect metabolism differentially, and the addition of 6-BA and KT can increase different secondary metabolites. In the two PGR groups, some primary metabolites such as L-phenylalanine, L-tyrosine, L-arginine, L-asparagine, and D-proline were significantly reduced. We suspect that under the action of PGRs, these decreased amino acids are derived into secondary metabolites such as umbelliferone, chlorogenic acid, and glutathione. Additionally, some of those secondary metabolites have a biological activity and can also promote the plant growth. Our results provide a basis for the targeted cultivation and utilization of S. tschiliensis, especially the expression of metabolites related to PGR application.

Plants on (brassino)steroids.

Long-distance transport is central to the mode of action of plant growth regulators. But in the case of brassinosteroids, spatiotemporal control of biosynthesis and local movements of the bioactive molecule or its precursors result in local hormone accumulation, functioning as a positional cue in root morphogenesis.

Carrageenan oligomers and salicylic acid act in tandem to escalate artemisinin production by suppressing arsenic uptake and oxidative stress in Artemisia annua (sweet wormwood) cultivated in high arsenic soil.

The present study is aimed to elucidate the effects of concomitant application of irradiated carrageenan (IC) oligomers and salicylic acid (SA) on Artemisia annua L. varieties, viz. "CIM-Arogya" (tolerant) and "Jeevan Raksha" (sensitive) exposed to arsenic (As) stress. Artemisia annua has been known for its sesqui-terpene molecule artemisinin, which is useful in curing malaria. The two compounds, IC and SA, have been established as effective plant growth-promoting molecules for several agricultural and horticultural crops. To test the stress tolerance providing efficacy of IC and SA, the characterization of various physiological and biochemical parameters, growth as well as yield attributes was done in the present experiment. A. annua plants were given various treatments viz. (i) Control (0) (ii) 45 mg As kg-1 of soil (iii) 80 mg L-1 IC+45 mg As kg-1 of soil (iv) 10-6 M SA+45 mg As kg-1 of soil (vi) 45 mg As kg-1 soil+80 mg L-1 IC+10-6 M SA. Plants of A. annua suffered from prominent injuries due to oxidative stress generated by As. At 90 and 120 days after planting (DAP), As toxicity was manifested in reduction of most of the studied growth parameters. However, antioxidant activities such as catalase (CAT), peroxidase (POX), superoxide dismutase (SOD), and ascorbate peroxidase (APX) were enhanced in As-stressed conditions and their activities were further enhanced in IC+SA-treated plants. Application of As significantly produced the highest artemisinin content and yield in "CIM-Arogya" over "Jeevan Raksha." Noticeably, the selected plant growth regulators (PGRs) (IC and SA) applied individually through foliage were found efficient, though, the concomitant effect of PGRs was much pronounced compared to their alone application in countering the toxicity of As. The interactive action of PGRs escalated the overall production (yield) of artemisinin (58.7% and 53.8%) in tolerant and sensitive varieties of A. annua in the presence of soil As. Conclusively, the concomitant application of IC and SA proved much effective and successful over their individual use in exploring the overall development of A. annua subjected to As stress.

Protagonist Action of Plant Growth Regulators and Sublethal-Temperature in Inducing Thermotolerance in Green Gram (Vigna radiata) Seedlings

Protagonist Action of Plant Growth Regulators and Sublethal-Temperature in Inducing Thermotolerance in Green Gram (Vigna radiata) Seedlings

Inducing resistance of cucumber plants to diseases by using plant growth regulators

Goal. To investigate the influence of plant growth regulators (PGR) and microfertilizer as plant resistance inducers for reducing the development of cucumber diseases in film greenhouses.
 Methods. Field and laboratory.
 Results. Analysis of the activity of total peroxidase showed a positive dynamics of activation of this enzyme - an increase of 1,2 – 2,2 times, which is 14,3 – 54,6%. It was the highest in the version with the use of Epin extra and salicylic acid. For the third day after plant treatment, the enzyme activity increased to 74.7-75.1 mg-ekv/g·s, Due to increased plant resistance, a decrease in the level of infestation of cucumber plants is noted. Depending on the drugs, the intensity of development of root rot in the average years of research was kept within 12.3-17.7 % at 30.5 % in the control. The smallest development of root rot was observed after application of microfertilizer CompleMet – 12.3 %. Treatment of plants by growth regulators led to a decrease in the level of damage of cucumber by downy mildew. The smallest development of the disease was noted in variants with Vimpel Maxi, Epin extra and CompleMet – 8.5% at 13.7% in control.
 Conclusions. The tendency to increase the level of activity of peroxidase in cucumber plants after treatment with plant growth regulators is revealed, which indicates an increase in the activity of one of the key non-specific protective reactions and, consequently, unspecific plant resistance. The effectiveness of PGR on the basis of humic acids, biologically active substances and microfertilizer CompleMet as an inducer of plant resistance to diseases has been established. The most effective against root rot is microfertilizer CompleMet – 60 % among growth regulators: Vimpel Maxi, salicylic acid, Epin extra (biological efficiency – 56, 55, 52 % respectively). Influence from the action of PGR against downy mildewis observed at the initial stages of disease development. A noticeable effect is observed when applying Epin extra, Vimpel Maxi and CompleMet (biological efficiency – 38%).

The acute combined action of plant growth regulator succinate-2,6-dimethylpyridine-N-oxide-and some pesticide active ingredients

The acute combined action of plant growth regulator succinate-2,6-dimethylpyridine-N-oxide-and some pesticide active ingredients

The acute combined action of plant growth regulator – 2,6-Dimethyl- N -oxide of pyridine and some pesticide active ingredients

The acute combined action of plant growth regulator – 2,6-Dimethyl- N -oxide of pyridine and some pesticide active ingredients

Desiccation tolerance in seeds of Annona emarginata (Schldtl.) H. Rainer and action of plant growth regulators on germination

Annona emarginata (Schldtl.) H. Rainer (araticum-de-terra-fria) is used as a rootstock for several species of Annonaceae. It is suggested that these seeds should be sown immediately after extraction and, therefore, they could be intolerant to desiccation. There are several mechanisms involved with desiccation tolerance. Soluble sugars, for example, can accumulate and act as osmoprotectants for the membrane system during desiccation. The aim of this study is to assess desiccation tolerance in A. emarginata seeds. In addition, we examined the soluble sugars involved in desiccation tolerance. Finally, we determined the effect of gibberellic acid (GA4+7) and N-(phenylmethyl)-aminopurine in promoting the germination of seeds with different water contents. The experiment consisted of a randomized 4x5 factorial design (desiccation levels x concentration of growth regulators). After drying, seeds containing 31 (control), 19, 12 and 5% water were incubated in different concentrations of GA4+7 N-(phenylmethyl)-aminopurine (0, 250, 500, 750 and 1000 mg L-1) for 60 hours. The experiment was conducted in a germination chamber with alternating temperature and photoperiod of 20oC for 18 hours of darkness and 30oC for 6 hours of light. We analyzed electrical conductivity, germination rate, mean germination time, germination speed, frequency and uniformity of germination, percentage of dormant seeds and soluble sugar profile in intact seeds through high-performance liquid chromatography (HPLC). The data were subjected to analysis of variance, and the means were compared using Tukey's test at a threshold of p<0.05. The results showed that seeds of A. emarginata appears to be desiccation tolerant and, also, that sucrose increases when seed water content is reduced to values as low as 12%, exogenous GA4+7+N-(phenylmethyl)-aminopurine improves its germinability.

Химический состав столового картофеля в зависимости от внекорневых обработок регуляторами роста растений и гуминовыми удобрениями

Изучено действие регуляторов роста растений и гуминовых удобрений при выращивании столового картофеля на химический состав растений. Установлено, что они способствуют изменению макро- и микроэлементного состава в ботве и клубнях картофеля, снижению содержания тяжёлых металлов в клубнях картофеля на 17 - 39 %.

Action of plant growth regulators and salinity on seed germination of Ceratoides lanata

Ceratoides lanata (Pursh) J.T. Howell is a shrub with numerous annual branchlets from the family Chenopodiaceae and is widely distributed in brackish water playas of northern Utah. Seeds had no dormancy, and about 90% of the seeds germinated in nonsaline control. Seed germination decreased with the increase in salinity, and more than 10% of the seeds germinated at 900 mmol/L NaCl. Almost all seeds germinated in less than 24 h, and no additional seed germinated after this time. Gibberellic acid had no effect in alleviating salinity effects; however, kinetin and fusicoccin substantially alleviated the effect of salinity on germination, while ethephon almost completely reverted the effect of salinity.Key words: Ceratoides lanata, gibberellic acid, ethephon, fusicoccin, halophytes, kinetin.

Plant cell suspension cultures as model systems for investigating growth regulating compounds

Several plant growth regulators were investigated for their activity in cell suspension cultures of Glycine max, Gossypium hirsutum and Zea mays. The effect on the growth of the cell cultures was traced by means of cell counting and determining packed cell volume and turbidity of the suspensions. The growth retardant 5-(4-chlorophenyl)-3,4,5,9,10-pentaaza-tetracyclo-5,4,10(2,6) ,0(8,11)-dodeca-3,9-diene (NDA) and, to a slightly lesser extent, ancymidol proved to be the compounds with the greatest inhibitory action on cell division growth of all three cell cultures. In the case of cotton this effect was accompanied by increased synthesis and secretion of cell-wall material. Staining methods showed that, especially in the case of NDA, a high percentage of cells could be considered as viable, and showed thus that NDA inhibits the cell division process while the cells remain metabolically active. The effects of 1,1-Dimethyl-piperidiniumchloride (DPC), a genuine growth retardant of cell propagation, and, with less efficiency, N-trimethyl-(β-chloroethyl)-ammoniumchloride (CCC) in cotton, the triazole LAB 117 682 in soybean and maize, and, to a lesser extent, (2-isopropyl-5-methyl-4-trimethyl-ammoniumchloride)-phenyl-l-piperidiniumcarboxylate (AM0-1618) in soybean can be regarded as species-specific. Otherwise, CCC and particularly daminozide exhibited no action at the concentrations used. A comparison of the data from hydroculture studies with soybean and maize seedlings showed considerable agreement with the effectiveness of the substances in the corresponding cell cultures. Thus, cell cultures can be used to identify and screen substances with growth-influencing activity, and may also offer new ways to elucidate the mode of action of plant growth regulators.

Introduction to The Session

Abstract Probably the area of horticultural science changing most rapidly in recent years is that concerned with chemical plant growth regulation. Certainly the technology of fruit production has been dramatically influenced by growth regulators and the list of cultural practices that can benefit from growth regulators is growing steadily. Many of us have been hard pressed to keep up with the required field testing. We have little time to explore more fundamental aspects of growth regulator research such as synthesis and formulation of new materials, or even more importantly, to examine the mode of action of plant growth regulators in our particular horticultural systems. It is hoped that these invited papers, with their emphasis on fundamentals, will help many of us to put our research effort into a more realistic perspective.

Action of Plant Growth Regulators. IV. Adsorption of Unsubstituted and 2,6-Dichloro-aromatic Acids to Oat Monolayers

The adsorption of chloro-aromatic acids to monomolecular layers of oat squashes is reported in earlier papers but it was not possible by the technique used, to measure unambiguously the adsorption of unsubstituted and 2,6-dichloro-aromatic acids. This has now been achieved by a modification of the earlier method and involves assessments of competitive adsorption between the unknown acid and a standard acid, using measurements of surface potential.Benzoic and phenoxyacetic acids were not adsorbed but phenylacetic acid was weakly adsorbed. The second ring in naphthalene and naphthoxyacetic acids greatly increased adsorption. Substitution of the 2 and 6 positions in the phenyl and phenoxyacetic acids resulted in low adsorption but 2,6-disubstituted phenoxybutyric and benzoic acids were more highly adsorbed.The adsorption values from earlier work are combined and discussed in relation to the growth-regulating activity of the acids. It is conciuded that there is no direct relation embracing all acids between adsorption and activity, notable exceptions being those substituted by chlorine in the 3-position of the aromatic ring. However, for a number of acids it is suggested that activity is limited not only by their ability to interact at enzyme sites but also by the amount of acid immobilised by adsorption when moving to these sites. It is also concluded that the hydrophilic/lipophilic balance of a growth regulator sometimes used as a guide to its activity, is an unreliable indication of interfacial behaviour.

Action of Plant Growth Regulators. III. Adsorption of Aromatic Acids to Oat Monolayers

In an earlier paper (2) it was concluded that a broad correlation exists between the resistance of a plant to 2-methyl-4-chlorophenoxyacetic acid (MCPA) and its ability to adsorb the growth regulator. This lent support to the suggestion that the foundation of species resistance may be partly based on the extent of MCPA adsorption to sites not concerned in the physiological response. This work has been extended since it follows that the biological activity of different growth regulator molecules on a given plant species may also be limited by the extent of their adsorption, and a correlation may exist between biological activity and the adsorption of growth regulators to plant constituents. This has already been implied by Veldstra and Booij (9) when noting that chlorination of the phenoxy compounds generally appeared to increase their activity but chlorination of naphthoxy compounds reduced their activity. Similarly, these authors consider that certain trichlorophenoxy acetic acids have exceeded the optimum size and hence optimum interaction with plant membranes, for high biological activity. Three series of acids were investigated. The phenoxyacetic and benzoic acids were selected in view of the importance of some members of these series as herbicides. The phenylacetic acids were studied as a result of earlier observations at Jealott's Hill in 1953 that 2,3-dichloro and 2,6-dichlorophenylacetic acids were compounds with biological activity similar in character but somewhat inferior to MCPA. This paper presents physical measurements of the adsorption of the acids to monolayers from the squashes prepared from oat leaves using the Langmuir trough. No biological data are presented in this paper but it is hoped it will be possible to seek a correlation when the results of biological tests on phenylacetic acids being made by various research teams become available. It is proposed to present these in Part IV of this series. MATERIALS AND METHODS

The Fate of Long Chain Esters of 2,4-D in Plants

STERS of the chlorophenoxyacetic acids are generally considered to EL be more phytotoxic than the acid or acid salts (3, 12, 20). Hence the esters have found wide use in herbicidal formulations (12). Much research has been done on the mode of action of plant growth regulators, but the fate of neutral derivatives of active acids has received little attention, even though an acid side chain is one of the molecular requirements for growth substance activity (13). The importance of 2,4-D esters and esters of other growth substances justified a study of the fate of 2,4-D esters in plants. Hagen, et al. (9) have shown with the butyl ester of 2,4-D and castor bean lipase that hydrolysis of these esters can be catalyzed by plant enzymes. The fate of long-chain esters of 2,4-D in plants has been studied by three assay procedures. A preliminary report has been presented (18).

On the Action of Plant Growth Regulators. II. Adsorption of MCPA to Plant Components.

On the Action of Plant Growth Regulators. II. Adsorption of MCPA to Plant Components.