Effect Of Cytokinins Research Articles

Effect of auxins and cytokinin on micropropagation of Impatiens sirindhorniae Triboun & Suksathan in vitro

ISHS IX International Scientific and Practical Conference on Biotechnology as an Instrument for Plant Biodiversity Conservation (physiological, biochemical, embryological, genetic and legal aspects) Effect of auxins and cytokinin on micropropagation of Impatiens sirindhorniae Triboun & Suksathan in vitro

Cytokinin promotes growth cessation in the Arabidopsis root

The Arabidopsis root offers good opportunities to investigate how regulated cellular growth shapes different tissues and organs, a key question in developmental biology. Along the root's longitudinal axis, cells sequentially occupy different developmental states. Proliferative meristematic cells give rise to differentiating cells, which rapidly elongate in the elongation zone, then mature and stop growing in the differentiation zone. The phytohormone cytokinin contributes to this zonation by positioning the boundary between the meristem and the elongation zone, called the transition zone. However, the cellular growth profile underlying root zonation is not well understood, and the cellular mechanisms that mediate growth cessation remain unclear. By using time-lapse imaging, genetics, and computational analysis, we analyze the effect of cytokinin on root zonation and cellular growth. We found that cytokinin promotes growth cessation in the distal (shootward) elongation zone in conjunction with accelerating the transition from elongation to differentiation. We estimated cell-wall stiffness by using osmotic treatment experiments and found that cytokinin-mediated growth cessation is associated with cell-wall stiffening and requires the action of an auxin influx carrier, AUX1. Our measurement of growth and cell-wall mechanical properties at a cellular resolution reveal mechanisms via which cytokinin influences cell behavior to shape tissue patterns.

Auxin/Cytokinin Antagonistic Control of the Shoot/Root Growth Ratio and Its Relevance for Adaptation to Drought and Nutrient Deficiency Stresses.

The hormones auxin and cytokinin regulate numerous aspects of plant development and often act as an antagonistic hormone pair. One of the more striking examples of the auxin/cytokinin antagonism involves regulation of the shoot/root growth ratio in which cytokinin promotes shoot and inhibits root growth, whereas auxin does the opposite. Control of the shoot/root growth ratio is essential for the survival of terrestrial plants because it allows growth adaptations to water and mineral nutrient availability in the soil. Because a decrease in shoot growth combined with an increase in root growth leads to survival under drought stress and nutrient limiting conditions, it was not surprising to find that auxin promotes, while cytokinin reduces, drought stress tolerance and nutrient uptake. Recent data show that drought stress and nutrient availability also alter the cytokinin and auxin signaling and biosynthesis pathways and that this stress-induced regulation affects cytokinin and auxin in the opposite manner. These antagonistic effects of cytokinin and auxin suggested that each hormone directly and negatively regulates biosynthesis or signaling of the other. However, a growing body of evidence supports unidirectional regulation, with auxin emerging as the primary regulatory component. This master regulatory role of auxin may not come as a surprise when viewed from an evolutionary perspective.

Micropropagation of pokeweed (Phytolacca americana L.) and comparison of phenolic, flavonoid content, and antioxidant activity between pokeweed callus and other parts.

BackgroundPokeweed (Phytolacca americana L.) is regarded as an invasive plant in many parts of the world but possesses therapeutic characteristics used for antitumor and rheumatism treatment. This study investigated the effects of auxins and four explants on pokeweed callus induction. The effects of cytokinins and combinations between cytokinins and NAA on shoot and root induction were also studied. TPC, TFC and antioxidant activity of calli were screened and compared with other pokeweed plant parts.MethodsFour explants were used to induce callus using 2,4-D and IBA at 1, 2, 3 and 4 mg/l for each auxin. Direct shoot organogenesis from nodal explants was investigated using BAP, kinetin and TDZ (1, 2 and 4 mg/l for each cytokinin). Combined effects between cytokinins and NAA at 0.1, 0.2 and 0.3 mg/l were further simultaneously estimated with root induction. Calli derived from the leaves were compared with other plant parts for TPC, TFC and antioxidant activity using the Folin-Ciocalteu, AlCl3 colorimetric assay and DPPH assays, respectively.ResultsResults showed that MS medium containing 2 mg/l 2,4-D induced callus formation on leaf explants that provided highest fresh and dry weights. Three types of synthetic cytokinins as kinetin, TDZ and BAP were used for direct shoot organogenesis from pokeweed nodes. MS medium containing 2 mg/l kinetin was effective in stimulating normal shoots, with the largest number of shoots and leaves and the longest shoots. The combination between cytokinins and NAA showed no positive effect on shoot and root induction from pokeweed nodal explants. For TPC and TFC determination, pokeweed seeds and leaves possessed the highest phenolic and flavonoid contents, respectively. Highest phenolic content of pokeweed seeds led to lowest IC50 by DPPH assay. Phenolic content was higher than flavonoid content.ConclusionResults suggested promising conditions for callus induction. Leaf explants cultured on MS medium with 2 mg/l 2,4-D and nodal explants cultured on MS medium with 2 mg/l kinetin provided the largest number of normal shoots and leaves. NAA did not show positive effects on shoot and root induction when combined with cytokinins. Chemical constituent screening indicated that seeds and leaves provided highest TPC and TFC, respectively, while pokeweed calli contained higher phenolic than flavonoid content. This is the first report describing chemical constituent screening and antioxidant activity of calli and other parts of the pokeweed plant. Results provided significant information to further enhance bioactive compound contents of pokeweed calli using elicitation methods.

Особенности культивирования российских и зарубежных сортов жимолости съедобной (Lonicera edulis Turcz.) in vitro

Introduction. The demand for honeysuckle berries and planting material is growing. Clonal micropropagation is the most effective method for industrial plantations. The research objective was to study the effect of cytokinins and auxins on Russian and Canadian honeysuckle microshoots and roots.
 Study objects and methods. The study featured regenerated honeysuckle (Lonicera edulis Turcz.) of three Russian cultivars (Bakcharsky Velikan, Doch Velikana, Yugana) and two Canadian cultivars (Boreal Beauty, Boreal Beast). The experiment focused on the effect of sterilizing agents and sterilization time on the viability of honeysuckle explants at the stage of culture introduction in vitro. The effect of the growth regulator Cytodef in the QL nutrient medium on organogenesis was studied at the stage of micropropagation proper, the effect of auxin IBA on plant root formation – at the stage of rooting in vitro.
 Results and discussion. The greatest viability of honeysuckle explants (80–94%) was registered in the samples affected by Lizoformin 3000 (5%) and silver nitrate (0.2%) as sterilizing agents with a sterilization time of 10 min at the stage of in vitro culture introduction. The biggest quantity (8.8 pcs.) and total length (40.1 cm) of microshoots were observed when the content of cytokinin Cytodef in the culture medium QL was 0.3 mg/L at the stage micropropagation proper. The Boreal Beast cultivar had the largest total length of shoots (29.0 cm). The biggest quantity (5.5 pcs.) and total length (30.8 cm) of roots resulted from 0.5 mg/L of auxin IBA at the stage of rooting in vitro. Coconut substrate produced the highest survival rate (92–99%) at the stage of adaptation to non-sterile conditions in vivo, with the greatest number of leaves (8.1–10.2 pcs.) observed in Canadian cultivars.
 Conclusion. Cytodef and IBA proved to be effective growth-regulating substances for microplants of Russian and Canadian honeysuckle cultivars in vitro, which makes them promising for berry plantations.

Effect of cytokinin and yeast extract foliar application on wheat yield and its components (Triticum aestivum L.) under different levels of zinc

Effect of cytokinin and yeast extract foliar application on wheat yield and its components (Triticum aestivum L.) under different levels of zinc

ВЛИЯНИЕ ИНДУКЦИИ СИНТЕЗА ЦИТОКИНИНОВ НА ФЛОЭМНЫЙ ТРАНСПОРТ АУКСИНА У IPT ТРАНСГЕННЫХ РАСТЕНИЙ ТАБАКА

As a model for the changes in the content of endogenous cytokinins, ipt-transgenic tobacco plants (Nicotiana tabacum L. cv. Petit Havana SR-1) were used. The total heating of plants caused the accumulation of cytokinins in shoots and a decrease in the delivery of auxins with phloem flow. The effect of cytokinins on the transport of auxins through the phloem is discussed, as well as limitations for the use of ipt transgenic tobacco plants as a model for studying the interaction of hormones.

Effect of cytokinin and yeast extract foliar application on vegetative growth parameters of wheat (Triticum aestivum L.) under different levels of zinc

Effect of cytokinin and yeast extract foliar application on vegetative growth parameters of wheat (Triticum aestivum L.) under different levels of zinc

Effects of gibberellin and cytokinin on phenolic and volatile composition of Sangiovese grapes

Cytokinin and gibberellin are plant growth regulators (PGRs) used to increase berry size in seedless table grapes but their effects on wine grape phenolics and volatiles was not studied. In the current study, gibberellic acid (GA3) and synthetic cytokinin forchlorfenuron (CPPU) and their combination were applied to fruitlets of Sangiovese and berries were sampled 79 days following application. All the treatment significantly increase berry diameter and berry weight and CPPU containing treatment increased skin thickness. All treatments reduced sugar accumulation and color development but did not have an effect on acid levels. HPLC analysis showed that total flavan-3-ols level was increased by CPPU, GA containing treatments reduced the levels of flavonols and anthocyanins were significantly reduced in all the treatment (≈50%). Phloroglucinol analysis showed that proanthocyanidins level were significantly increased whereas the mean degree of polymerization was reduced from 40 to ≈21 by all the treatments. GC–MS analysis of berries showed a decrease in fatty acid derived volatile compounds by all treatments with potential impact on flavor. Analysis of wine phenolics in subsequent harvest was in general agreement with the previous results. In summary, this study provides new information on how PGRs can change berry composition and subsequently wine attributes.

ГИДРАВЛИЧЕСКАЯ ПРОВОДИМОСТЬ, ФОРМИРОВАНИЕ АПОПЛАСТНЫХ БАРЬЕРОВ И АКТИВНОСТЬ АКВАПОРИНОВ У ТРАНСГЕННЫХ РАСТЕНИЙ ТАБАКА С ИНДУЦИРОВАННЫМ НАКОПЛЕНИЕМ ЦИТОКИНИНОВ

In this study, we discovered the effect of the induction of the ipt gene, which increases the concentration of cytokinins in transgenic tobacco plants, on transpiration and hydraulic conductance. The novelty of the work was to study the mechanisms of involvement of cytokinins in the regulation of the hydraulic conductivity of tobacco plants with an increase in transpiration demand due to the accumulation of cytokinins and the opening of stomata. The effect of an increased concentration of cytokinins on the active transport of water through aquaporins was revealed by inhibiting them with mercury chloride. The deposition of lignin and suberin in the apoplast, which determines its conductivity for water, was detected with berberine after repeated daily heat inductions. It was found that cytokinins increase the hydraulic conductivity of tobacco plants by up-regulation the activity of aquaporins and inhibiting the formation of apoplast barriers. The simultaneous effect of cytokinins on both stomatal and hydraulic conductivity allows plants to coordinate the evaporation of water from the leaves and its inflow from the roots, thereby maintaining the water balance and leaf hydration.

Effect of cytokinin-type compounds on the self-regulation of plant water status under conditions of adverse humidity variation and repeated water stress

The effect of cytokinin, thiourea and complex chemical Polyel + F on the ability of water status self-regulation, photosynthesis and on the efficiency of water use by plants under conditions of humidity fluctuations and repeated drought was studied. Glycine max (Merr) L. plants of ‘Nadejda’, ‘Moldovitsa’ and ‘Magia’ cultivars grown in the Mitcherlih vegetation pots with volume of 40 kg soil and exposed to the drought stress at the phases "first trifoliate leaf" and "flowering – pod formation” were used in the study. The studied compounds’ property to increase the plant resistance to unfavorable humidity fluctuations and conditions of repeated moderate drought has been established. Plants that have endured a moderate drought in the early stages of ontogenesis become more tolerant to moderate water stress during flowering and pod formation. The effect of tolerance inducing in plants pre-treated with respective compounds is manifested by increasing the water retention capacity, keeping the internal aqueous medium at a comparatively higher level. After restoring optimal moisture conditions, the plants pretreated with thiourea and Polyel + F restore their functional processes more integrally. The research data suggest that changes occurring at the cellular level in the early stages of development, caused by moderate moisture deficiency and conferring resistance, are initiated when water content decreases and can be consolidated when water loss is not too drastic.

The effect of cytokinins on shoot proliferation, biochemical changes and genetic stability of Rhododendron ‘Kazimierz Odnowiciel’ in the in vitro cultures

Shoot proliferation is a very important micropropagation phase, decisive for economic efficiency of this method for a given taxon. To obtain a high multiplication ratio and a good quality of microshoots a detailed propagation protocol must be developed for particular species or even cultivars. Rhododendron ‘Kazimierz Odnowiciel’ is a relatively new cultivar distinguished by large, beautiful flowers and high frost resistance so there is a need to develop an efficient method of its propagation to satisfy a growing demand for this plant. The aim of the experiment was to evaluate effects of cytokinins: meta-Topolin (mT), zeatin (ZEA), 6-benzyladenine (BA), thidiazuron (TDZ), 2-isopentenyladenine (2iP), or the combination of 2iP+ZEA on proliferation of shoots in R. ‘Kazimierz Odnowiciel’ cultured on Anderson’s medium (AN). Biochemical changes in plant material affected by cytokinins during this phase of micropropagation were determined and occurrence of genetical changes was followed using ISSR markers. TDZ, ZEA or the combination of ZEA+2iP resulted in 100% explant regeneration. On the medium with TDZ or ZEA over two new shoots per explant were produced but the highest proliferation was attained on the medium containing ZEA+2iP – over three shoots per explant. Microshoots developed in this treatment had also the highest contents of chlorophyll, carotenoids and soluble sugars as well as the highest catalase activity. Microshoots formed on the medium with zeatin showed the lowest polymorphism (below 4%) relative to a stock plant.

Effect of Nano Potassium and Cytokinins in the Vegetative Growth Traits of Faba Bean (Vicia faba L.)

A field experiment was carried out at the Al-Hsai District/Falluja City/Al-Anbar Province during the winter season 2020-2021. To study the effect of Nano potassium (NK) and Cytokinin (CTK) on the growth, and quality of the local cultivar of faba bean. Split plot system was used according to the design of a completely randomized block design R.C.B.D and three replications. The main blocks included four concentrations of CTK; 0, 50, 100, and 150 mg. L-1, while the secondary blocks included four concentrations of NP; 0, 1, 2, and 3 g.L-1. The results of the experiment were summarized as follows: The NK concentrations influenced all the studied properties. Where the concentration of 2 g.L-1 affected most of the studied properties, like the plant height of 122.9 cm, the number of branches per plant of 14.34 branches. plant-1, the number of leaves per plant of 157.9 leaves. plant-1, leaf area 4918 cm2. plant-1, and leaf content of chlorophyll of 48.28 SPAD, while the control treatment outperformed in the trait of flowering beginning with the lowest average number of days (61.67 days). The CTK concentration of 100 mg. L-1 affected significantly on most of the studied traits. Where it prevails in plant height of 130.97 cm, number of branches per plant 13.55 branches. plant-1, number of leaves per plant of 165.5 leaves. plant-1, and LA of 5689 cm2. Plant-1. The highest level of Leaf chlorophyll content of 44.98 SPAD was found in the CTK concentration of 50 mg. L-1, which was not significantly different from 150 mg.L-1. Whereas the lowest number of days from cultivation to flowering starts of 62.58 days were found at control treatment. The interaction between NK and CTK had affected most of the studied traits, as the interaction of 2 gm. L-1 and 100 mg. L-1 (NK x CTK) has the highest average of plant height (158 cm) and number of leaves per plant (186.1 leaves. plant-1). Whereas the interaction between 1 gm. L-1 NP and 50 gm. L-1 CTK has the highest number of branches per plant 16.61 branches. Plant-1. Moreover, the highest average of LA (6812 cm2.plant-1) was found in the interaction between 1 gm. L-1 NP and 100 mg.L-1 CTK. The highest Leaf chlorophyll content of 56.53 SPAD was found in the interaction of 2 gm. L-1 of NP and 50 gm.L-1 of CTK. Whereas, the same interaction has an insignificant difference on number of days from cultivation to flowering starts trait.

Callus inducement of Toona sinensis: Potential agents against SARS-Corona virus replication

Bioprospecting of anti-SARS-corona virus phytochemical agents is an important issue today as an alternative to chemical drugs whose effectiveness has not been fully successful with no light effect. Quercetin, a component of Toona sinensis young leaves extract, was reported to have anti-viral activity against SARS-corona virus replication in vitro. Currently, the low efficiency of secondary metabolite production is an obstacle. Production of secondary metabolites from callus induction in vitro is considered more efficient and in a short time for commercial applications. The composition of hormones in callus media affects the secondary metabolites formed. The study was conducted to determine the effect of synthetic hormones auxin (BAP) and cytokinin (NAA) on callus percentage, fresh and dry callus cell weight and the average time of callus formation. The call percentage (100%) was obtained in different combinations of BAP and NAA in MS medium. The highest fresh weight of callus (165.50 gL−1) and dry cell weight (28.47 gL−1) were observed in MS medium (1.5 mgL−1 BAP and 1 mgL−1 NAA) within 7 days initial formation time of callus. The results showed that all the indices measured were positively correlated with callus induction in T. sinensis.

Synergistic effect of cytokinins on in vitro propagation of Stereospermum suaveolens using nodal explants

Synergistic effect of cytokinins on in vitro propagation of Stereospermum suaveolens using nodal explants

Effects of exogenous KT and BA on fruit quality in strawberry (Fragaria vesca)

ABSTRACT Due to developing production methods and increasing consumption levels, improvement of fruit quality has become a focus of research. Cytokinins are important hormones that affect fruit quality. In this study, exogenous KT (Kinetin) and BA (6-Benzylaminopurine) were applied 1, 3, 5, 7 and 9 days after pollination to study the effect of cytokinins on the quality of strawberry (Fragaria vesca) fruit. The results showed that exogenous KT and BA significantly increased the weight and soluble sugar content of strawberry fruit at late stages of fruit development (27 and 31 DAP). KT and BA treatments up-regulated the expression levels of FvePAL6, FveCHS, FveMYB1, and FveMYB10 at 31 DAP, thus increasing the anthocyanin content. At the red fruit stage, the anthocyanin content of fruits treated with KT and BA were 1.59 and 1.45 times, respectively, higher than that of the control. KT and BA elevated the levels of antioxidants such as ascorbic acid and total phenolics. Also, KT and BA increased the content of myricetin, quercetin, and kaempferol. In addition, KT and BA reduced the relative contents of several aromatic substances. Our results indicate that KT and BA treatments had a significant effect on the improvement of strawberry fruit quality.

Adaptive effect of cytokinin on soybean plants under the action of chronic ultraviolet B radiation

Adaptive effect of cytokinin on soybean plants under the action of chronic ultraviolet B radiation

Effect of cytokinins on growth and phenylpropanoid accumulation in Tartary buckwheat sprouts (Fagopyrum esculentum Moench)

This study analyzed the effect of plant hormones, zeatin, 6-benzyl amino purine (BAP), kinetin, and thidiazuron (TDZ) on the growth of Tartary buckwheat sprouts and analyzed the fresh weight, shoot and root length, and production of phenolic compounds. All the hormone-treated plants at the lowest concentration (0.1 mg/L) showed the highest levels of growth parameters (fresh weight, shoot, and root length) when compared to the control. Among the various hormones treatment, the plant treated with 1 mg/L of BAP, kinetin, and zeatin showed the highest total phenolic level, whereas the TDZ showed the highest accumulation of total phenolic at the lowest concentration (0.1 mg/L). A total of 6 compounds were identified (4-hydroxybenzoic acid, caffeic acid, chlorogenic acid, p-coumaric acid, rutin, and trans-cinnamic acid) were quantified by high liquid performance chromatography (HPLC) after treatment of plant with different concentrations of hormones. Among these individual phenolic compounds, at the higher hormonal concentration (1 mg/L) the rutin showed the highest accumulation in BAP, zeatin, and kinetin treated sprout, whereas in the TDZ treated sprout the rutin content was highest at the lowest concentration (0.1 mg/L). From these results, it is suggested that BAP, zeatin, and kinetin at the lowest concentrations might positively enhance the growth of buckwheat sprouts, whereas at the highest hormonal treatment the accumulation of the phenolic compounds was higher. However, in TDZ treatment the growth and phenolic compound accumulation were highest at the lowest concentration. From these results, it is showed that suitable concentrations might enhance the growth and phenolic compound accumulation in Tatary buckwheat sprout.

Hormonal Regulation and Crosstalk of Auxin/Cytokinin Signaling Pathways in Potatoes In Vitro and in Relation to Vegetation or Tuberization Stages.

Auxins and cytokinins create versatile regulatory network controlling virtually all aspects of plant growth and development. These hormonal systems act in close contact, synergistically or antagonistically, determining plant phenotype, resistance and productivity. However, the current knowledge about molecular interactions of these systems is still scarce. Our study with potato plants aimed at deciphering potential interactions between auxin and cytokinin signaling pathways at the level of respective gene expression. Potato plants grown on sterile medium with 1.5% (vegetation) or 5% (tuberization) sucrose were treated for 1 h with auxin or cytokinin. Effects of these two hormones on expression profiles of genes belonging to main signaling pathways of auxin and cytokinin were quantified by RT-qPCR. As a result, several signaling genes were found to respond to auxin and/or cytokinin by up- or down-regulation. The observed effects were largely organ-specific and depended on sucrose content. Auxin strongly reduced cytokinin perception apparatus while reciprocal cytokinin effect was ambiguous and sucrose-dependent. In many cases, functional clustering of genes of the same family was observed. Promoters in some clusters are enriched with canonic hormone-response cis-elements supporting their direct sensitivity to hormones. Collectively, our data shed new light on the crosstalk between auxin- and cytokinin signaling pathways.

Збереження представників роду Drosera L. з використанням біотехнологічних методів

The peculiarities of obtaining planting material of rare representatives Drosera spatulate L. and Drosera aliciae L. using microclonal propagation in order to preserve and cultivate them in ex vitro conditions were studied. The method of sterilization of D. spatulate and D. aliciae explants with 80-90% obtaining aseptic material has been developed. The influence of different sterilization options on the development of microshoots has been studied. The best mode of sterilization is 0,1% solution of AgNO3 and 12.5% solution of H2O2. The features of organogenesis and regeneration of the whole organism from cultivated tissues and organs of Drosera L. was investigated. The effect of exogenous growth regulators at different stages of plant morphogenesis in vitro is shown. Improved conditions of rhizogenesis in vitro. It was found experimentally that MS nutrient media with the addition of 2 g∙l-1 PVP is optimal at the stage of introduction into culture in vitro D. spatulate and D. aliciae. The regeneration of microshoots of D. spatulate and D. aliciae depending on the type of explant and the composition of nutrient media was studied. Morphogenesis was most effective on nutrient media with the addition of 0.25 mg∙l-1 kinetin and on the hormone free MS media. Such cultivation conditions provided 100% regeneration of plants with a reproduction rate of 1:8. Studying the effect of cytokinins on the microclonal reproduction of D. spatulate and D. aliciae, it was found that the development and induction of multiple shoot formation in vitro is best performed on hormone free MS media. To induce the formation of the root system, it is necessary to add into MS nutrient media 0.5 mg∙l-1 IBA. According to the results of the research, a method of microclonal propagation was developed by cutting stem culture, which made it possible to obtain genetically stable, disease-free regenerating plants of D. spatulate and D. aliciae with an optimally formed root system and vegetative mass. The obtained homogeneous planting material can be used in floriculture, creation of terrariums, for pharmacological purposes and for the purpose of introduction. Keywords: Drosera L., microclonal reproduction, morphogenes.