The Effect of Plant Growth Regulators on Physico-Chemical Properties of Safflower (Carthamus tinctorius L.) Derived Biodiesel

Global concerns about the environmental impact of combustion emissions from petroleum fuels influence new research to seek for alternative energy sources. The current study investigates the possibility of using safflower (Carthamus tinctorius L.) as an alternative biodiesel raw material. Four plant growth regulators (PGR) were used to boost the production of safflower. Thirteen treatments were constituted from the four plant regulators and applied to the safflower crop arranged in completely randomised design, repeated three times. The results show that the effect of plant growth regulators was not more than that of the control. More studies have to be channelled towards the relationship between safflower and plant growth regulators.

Establishment of high frequency shoot regeneration system in Himalayan poplar(Populus ciliata Wall. ex Royle) from petiole explants using Thidiazuron cytokinin as plant growth regulator

Populus species are important resources for industry and in scientific study on biological and agricul- tural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan poplar （Populus ciliata wall. ex Royle）. The effect of TDZ alone and in combi- nation with adenine and NAA was studied on the regen- eration potential of petiole explants. The explants were excised from Himalayan poplar plants grown in glass- houses. After surface sterilization the explants were cul- tured on shoot induction medium. High percentage shoot regeneration （86 %） was recorded on MS medium sup- plemented with 0.004 mg L-1 TDZ and 79.7 mg L-1 adenine. The regenerated shoots for elongation and multi- plication were transferred to MS ＋ 0.5 mg L-1 BAP ＋ 0.2 mg L-1 IAA ＋ 0.3 mg L-1 GA3. Root re- generation from shoots developed in vitro was observed on MS medium supplemented with 0.10 mg L-1 IBA. Hi- malayan poplar plantlets could be produced within 2 months after acclimatization in a sterile mixture of sand and soil. We developed a high efficiency plant regeneration protocol from petiole explants of P. ciliata.

Effects of plant growth regulators, carbon sources and pH values on callus induction in Aquilaria malaccensis leaf explants and characteristics of the resultant calli

The endangered tropical tree, Aquilaria malaccensis, produces agarwood for use in fragrance and medicines. Efforts are currently un-derway to produce valuable agarwood compoundsn tissue culture. The purpose of this study was to develop an optimal growth medium, specif-ically, the best hormone combination for callus suspension culture. Using nursery-grown A. malaccensis, sterilized leaf explants were first incu-bated on basic Murashige and Skoog （MS） gel medium containing 15g/L sucrose and at pH 5.7. Different auxin types including 1-naphthaleneacetic acid （NAA）, 2,4-dichlorophenoxyacetic acid （2,4-D）, and indole-3-butyric acid （IBA）, were tested at various concentrations （0.55, 1.1 and 1.65 μM） using the basic medium. Leaf explants were incubated for 30 days in the dark. Callus induced by 1.1 μM NAA had the highest biomass dry weight （DW） of 17.3 mg;however the callus was of a compact type. This auxin concentration was then combined with either 6-benzylaminopurine （BAP） or kinetin at 0.55, 1.1, 2.2 or 3.3 μM to induce growth of friable callus. The 1.1μM NAA＋2.2μM BAP com-bination produced friable callus with the highest biomass （93.3mg DW）. When testing the different carbon sources and pHs, sucrose at 15g/L and pH at 5.7 yielded highest biomasses at 87.7mg and 83mg DW, respec-tively. Microscopic observations revealed the arrangement of the friable cells as loosely packed with relatively large cells, while for the compact callus, the cells were small and densely packed. We concluded that MS medium containing 15 g/L sucrose, 1.1 μM NAA ＋ 2.2 μM BAP hor-mone combination, and a pH of 5.7 was highly effective for inducing friable callus from leaf explants of A. malaccensis for the purpose of establishing cell suspension culture.

Joint Toxicity of Beauveria bassiana and Two Insect Growth Regulators on Beet Armyworm,Spodoptera exigua(Hübner)

Joint toxicity of Beauveria bassiana and two insect growth regulators, methoxyfenozide and hexaflumuron, on beet annywonn larvae, Spodoptera exigua （ Htthner）, were investigated. An obvious synergism effect of the two insect growth regulators with B. beauveria was observed. When the insect growth regulators at LC50 concentrations （25 × 10^-6 g/L for methoxyfenozide and 1 000 × 10^ -6 g/L for hexaflumuren） were mixed with B. bassiana at the volume ratio of 4： 1, the mixtures achieved the best efficacy. The co-toxicity co-efficient （CTC） of methexyfenozide and B. bass/ana was 285, and that of hexaflumuron and B. bass/ana was 208. Scanning electron microscope observation of the longitudinal section of S. exigua revealed obviously different patterns of integument in different treatment groups.

Improved germination of threatened medicinal Prunus africana for better domestication: effects of temperature, growth regulators and salts

Prunus africana is an endangered medicinal species and has been classified as a priority for domestication in Cameroon.However,the seeds rapidly lose their viability during storage at room temperature after 2–3 months.This study aimed to improve seed germination of P.africana by germinating at different temperatures(4℃,28℃)using different concentrations of growth stimulators(sodium nitrate and gibberellic acid)and different concentrations of salts.P.africana seeds had 91.7%germination at 4C after 1 month of storage.Growth regulators considerably influenced germination after 6 months and reached 66.0%with 10 mM gibberellic acid and 100%with 10 mM sodium nitrate.Approximately three shoots per seed were developed,an indication of polyembryony.Histochemical analyses revealed the presence of protein-like bodies close to the embryo axis and accumulations of starch after 7 days of germination.After 14 days,amyloplasts and dark protein bodies of various sizes were observed.The outcome of this study will contribute to improve the germination of P.africana for better domestication and conservation.

Determination of Residual Amount of 15 Plant Growth Regulators in Bean Sprouts by HPLC-MS/MS

[Objectives]This study was conducted to effectively monitor PGR residues in bean sprouts to provide guarantee for the food safety of agricultural products.[Methods]A high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for the determination of residues of 15 plant growth regulators(PGRs)in bean sprouts was established using bean sprouts as an experimental material.Samples were extracted with a solution containing 5%acetic acid-acetonitrile(1∶99,V/V),purified with anhydrous magnesium sulfate,and diluted with methanol solvent to constant volume.The solutions were filtered through 0.22μm filtering membrane and the target analytes were separated on a Phenomenex H18 column.The identification of each compound was established by retention time matching along with the accurate mass measurement of the precursor ions and their main fragment ions.The quantification was carried out using matrix-matched external standard method.[Results]The retention time of the 15 PGRs were found in the range from 5.8-11.7 min under the optimized conditions.The linear relation was good in the concentration range of 0.005-0.050μg/ml,and the correlation coefficients of the 15 PGRs were≥0.9990.The limits of detection were in the range of 0.03-0.92 g/kg,and the limits of quantification were in the range of 0.50-2.10μg/kg.The average recovery in the recovery test at 3 concentration levels was 80%-110%,and the relative standard deviations were in the range of 2.8%-7.5%.[Conclusions]This method is simple and accurate,and can quickly qualitatively and quantitatively analyze the residues of 15 PGRs in bean sprouts.The proposed procedure was simple,quick and accurate for the simultaneous determination of the 15 PGRs in bean sprout.

Synthesis,Crystal Structure and Plant Growth Regulatory Activity of 1-(3-Amino-[1,2,4]triazol-1-yl)-3,3-dimethyl-butan-2-one

The title compound 1-（3-amino-[1,2,4]triazol-1-yl）-3,3-dimethyl-butan-2-one（3） was synthesized by Hofmann-alkylation reaction of 1-chloro-3,3-dimethyl-butan-2-one（1） and ~1H-[1,2,4]triazol-3-ylamine（2） with equal amount of K_2CO_3 as acid acceptor. The structure of compound 3 was characterized by ~1H NMR, 13 C NMR, HRMS and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P21/n with a = 5.7227（8）, b = 27.924（4）, c = 6.2282（7） ？, β = 101.892（11）°, V = 973.9（2） ？~3, Z = 4, T = 180.00（10） K, μ（MoKα） = 0.087 mm^（-1）, Dc = 1.243 g/cm^3, 3832 reflections measured（3.648≤θ≤26.022°）, 1916 unique reflections（Rint = 0.0359, Rsigma = 0.0572） used in all calculations. The final R = 0.0557（I 〉 2σ（I）） and w R = 0.1276（all data）. Bioassay showed that 3 displayed excellent activity as plant growth regulator with inducing lateral root formation and enhancing primary root elongation at 0.27 mmol/L（50 ppm） in soybeen（He Feng-50）. Good water solubility was found with 50 mg in 1 m L of water. Therefore, application of 3 in agriculture is more environmentally friendly due to cosolvent-free condition, and results in improved abiotic-stress tolerance by affecting the root growth. And furthermore, it can be used as a precursor to investigate the function of regulating plant root growth.

Influencing in vitro clonal propagation of Chonemorpha fragrans(moon) Alston by culture media strength,plant growth regulators,carbon source and photo periodic incubation

Chonemorpha fragrans is an endangered medicinal woody climber,regarded among alternative plant sources of camptothecin.Camptothecin is a monoterpene indole anti-cancer alkaloid with annual trade value of over three billion U.S.dollars in the recent,and is used in the production of its analog drugs approved for the chemotherapy of cancer of varied types.Effects of plant growth regulators,culture media strength and photoperi-odic duration on the micropropagation ef ciency of C.fragrans from nodal segment explants were studied on Murashige and Skoog(MS)medium amended with Thidiazuron(TDZ),Benzylaminopurine(BAP)or Kinetin(Kin).Thidiazuron was more ef cient over BAP and Kin when half basal MS medium was used over full or quarter strength.Results of carbon source experiment showed sucrose as the most effective over glucose,fructose,and maltose in the clonal production.Studies on the photope-riodic incubation duration showed 12 h as the best light period and sub or supra-optimal resulted in the production of abnormal and albino micro shoots.Experimental results on the evaluation of physiological,biochemical parameters showed the role of pigment molecules and antioxidant systems in the production of albino micro shoots.

The43,000Growth - associated Protein Functions as a Negative Growth Regulator in Glioma.

Previous molecular analyses of human astrocytomas have identified many genetic changes associated with astrocy-toma formation and progression.In an effort to identify novel gene expression changes associated with astrocytomaformation,which might reveal new potential targets for glioma therapeutic drug design,we used the B8-RAS-transgenic mouse astrocytoma model.Using multiplex gene expression profiling,we found that

Effects of Three Plant Growth Regulators on Yield and Quality of Sunflower

Using Xinshikui No. 5 as the experimental material, the effects of different concentrations of mepiquat chloride （100, 200, 300,400, 500 mg/L）, chlormequat chloride （800, 1200,1 600, 2 000, 2 400 rag/L） and paclobutracol （50, 75, 100, 125, 150 mg/L） on yield and quality of sunflower were investigated. The results showed that plant growth regulators could improve the yield and quality of sunflower seeds to varying degrees. Specifically, 400 mg/L mepiquat chloride （ D4 ）, 800 mg/L chlormequat chloride （ Cl ） and 75 mg/L paelobutracol （ P2 ） significantly improved disk diameter, seed weight per disc, 100-sced weight, seed kernel rate and yield of sunflower; 400 mg/L mepiquat chloride （ D4 ）, 1 200 mg/L chlormequat chloride （ C2 ） and 75 mg/L paclobutracol （ P2 ） improved crude protein content, crude fat content, length and width of sunflower seeds. Based on comprehensive consideration, paclobutraeol is the most appropriate plant growth regulator for improving the yield and quality of sunflower in Xinjiang, and the optimal application concentration is 75 mg/L.

Research Advances in Detection Methods of Plant Growth Regulators for Agricultural Products

In recent years,plant growth regulators are widely used in agricultural products.As the toxicity of plant growth regulator residues has gained increasing concerns,trace analysis methods for plant growth regulators have been developed.In this paper,the major methods with advantages and disadvantages for the detection and pre-treatment of plant growth regulator residues in agricultural products were summarized,including gas chromatography(GC),high performance liquid chromatography(HPLC),chromatographic technique combined with mass spectrometry,enzyme-linked immunosorbent assay(ELISA),capillary electrophoresis(CE)and so on.Meanwhile,the development prospects were also discussed.

Effects of Tianda 2116 Plant Growth Regulator on Growth and Yield of Winter Wheat (Triticum aestivum L.)

To achieve optimum yield of wheat, supplementation of soil and foliar applied fertilizers with plant growth regulators is vital to assure effective assimilation of nutrients by plants. A trial was conducted at Gwebi Agricultural College Farm in Mashonaland West Province of Zimbabwe, during the 2012 winter wheat season (May to August), to evaluate the effects of differing times of application of Tianda 2116 plant growth regulator on the growth and yield of wheat (variety SC Sekuru). The trial was laid out in a Randomized Complete Block Design with three replications. The treatments were: Tianda 2116 applied at the following weeks after planting (WAP): 2 WAP, 3 WAP, 4 WAP, 5 WAP, 6 WAP, 14 WAP and no Tianda 2116 applied (control). No significant differences (P > 0.05) were noted among treatments for mean number of tillers per plant and mean number of spikes per plant. Application of Tianda 2116 at 2 and 3 WAP delayed flowering and physiological maturity. Early application of Tianda 2116 increased the number of spikelets per spike, thousand grain weight and grain yield. Conclusively, Tianda 2116 applied 2 or 3 WAP is effective in reducing growth while enhancing yield parameters in wheat production.

Effect of Variety and Growth Regulator Concentration on Success of Air Layering in Plum

The experiment was conducted at the Regional Spices Research Center, BARI, Gazipur during June 2016 to October 2017 to evaluate the effect of genotype and growth regulator (IBA) on the success and performance of plum air layering. Air layering was done on two plum varieties (BARI Alubokhara-1 and PD Gaz 004) using seven levels of IBA concentration (viz. 0, 1000, 2000, 3000, 4000, 5000 and 6000 ppm) under a complete randomized (factorial) design (CRD). Significant variation was observed on rooting, establishment and death of layers due to variety and IBA concentrations except rooting and separation time. The un-fruiting line PD Gaz 004 showed outstanding performance in rooting and survivability of layers over BARI Alubokhara-1. Poor rooting and lower establishment caused very high mortality of layers in BARI Alubokhara-1. Rooting and survivability, number of roots, length of roots and leaf production increased with the increasing levels of IBA concentration up to 5000 ppm. The maximum (10 out of 10) rooting success of layer with 65.83% and 59.17% establishment from PD Gaz004 was obtained when 3000 and 4000 ppm IBA was used, respectively. In BARI Alubokhara-1, the highest rooting success (3.08), establishment rate (29.42%), number of root (4.28/layer) and root length (5.08 cm) were recorded with 4000 ppm IBA concentration.

Effect of plant growth regulator on rate of twin seedlings of rice with polyembryony

Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie.ties with polyembryony(Shuang 3,Shuang 13and Lu 52)was conducted.The results showed

Simultaneous Determination of Plant Growth Regulators in Fruits Using a Modified Qu ECh ERS Procedure and UPLC–MS/MS

Six plant growth regulators frequently used in fruit were detected using UPLC–MS/MS including chlormequat chloride, GA3, forchlorfenuron,paclobutrazol, thidiazuron and 2,4-D. A modified Qu ECh ERS method was used in pretreatment: each compound was extracted with acetonitrile containing 1% acetic acid and cleaned with a mixture of ostade-cylsilane(ODS) and Mg SO_4. The detection was performed using electrospray ionization(ESI) and multiple reaction monitoring mode(MRM) and quantified using the external standard method. Results indicated that the calibration curves of six plant growth regulators were linear within the range of 1–100 μg·kg^(-1) with correlation coefficients over 0.999. The recovery at four spiked concentrations, 1, 20, 50, and 100 μg·kg^(-1), ranged from 60.77% to 119.43% and relative standard deviation(RSD) were between 0.18% and 32.94%. The limits of detection(LOD) and limits of quantitation(LOQ) were 0.01–0.14 μg·kg^(-1) and 0.02–0.46 μg·kg^(-1), respectively, for apples, 0.01–0.18 μg·kg^(-1) and 0.03–0.59 μg·kg^(-1) for grapes, 0.01–0.08 μg·kg^(-1) and 0.04–0.28 μg·kg^(-1) for kiwis, 0.003–0.110 μg·kg^(-1) and 0.01–0.38 μg·kg^(-1) for peaches, and 0.01–0.08 μg·kg^(-1) and 0.03–0.25 μg·kg^(-1) for oranges.

Improving crop drought resistance with plant growth regulators and rhizobacteria: Mechanisms, applications, and perspectives

Drought is one of the main abiotic stresses that cause crop yield loss.Improving crop yield under drought stress is a major goal of crop breeding,as it is critical to food security.The mechanism of plant drought resistance has been well studied,and diverse drought resistance genes have been identified in recent years,but transferring this knowledge from the laboratory to field production remains a significant challenge.Recently,some new strategies have become research frontiers owing to their advantages of low cost,convenience,strong field operability,and/or environmental friendliness.Exogenous plant growth regulator(PGR)treatment and microbe-based plant biotechnology have been used to effectively improve crop drought tolerance and preserve yield under drought stress.However,our understanding of the mechanisms by which PGRs regulate plant drought resistance and of plant-microbiome interactions under drought is still incomplete.In this review,we summarize these two strategies reported in recent studies,focusing on the mechanisms by which these exogenous treatments regulate crop drought resistance.Finally,future challenges and directions in crop drought resistance breeding are discussed.

Synthesis, bioactivity and functional evaluation of linker-modified allatostatin analogs as potential insect growth regulators

Insect growth regulators play an important role in integrated pest management strategies.The FGLa–allatostatins（ASTs）are a family of neuropeptides that can inhibit juvenile hormone（JH）biosynthesis by the corpora allata（CA）of Diploptera punctata in vitro,are regarded as insect growth regulator candidates.In the search for new potential mimics and to explore the effect of linker length on inhibiting JH biosynthesis,a series of AST analogs were synthesized by modifying the linker of K24,which was found to have a significant effect on JH biosynthesis in vitro in our previous study.Functional evaluation demonstrated that all the target compounds can activate the Dippu-Ast R,albeit with different potencies.Analog L6 with the longest linker（n=5）,exhibited not only a promising effect on inhibition of JH biosynthesis both in vitro and in vivo,but also good activity in inhibiting basal oocyte growth.Structure–activity relationships（SAR）studies showed that longer linkers provided greater contribution to activity.

Influences of Plant Growth Regulators， Basal Media and Carbohydrate Levels on Cell Suspension Culture of Panax ginseng

A cell suspension culture of Panax ginseng which may be continuously subcultured has been established. Embryogenic callus derived from clutured young leaves was used to initiate the culture.Plant growth regulators, basal medium formula and carbohydrate levels were examined to determine their various effects on suspension culture cell growth and development. The best selection of plant growth regulator, hasal medium and carbohydrate level is 2 mg / L 2,4-D: 0.5 mg / L KT,MS and 3% sucrose respectively.

Ethanol Metabolism in Calluses of Several Selected Plant Species on Two Typical Plant-Growth-Regulator Balanced Media

For investigation on the characteristics of ethanol metabolism in tissues of different plant species, calluses from eight selected plant species were cultured on medium supplemented with ethanol in tightly sealed culture flasks. Changes of the ethanol level were detected by gas chromatography. During the culture period, the calluses of tobacco, potato and petunia were, able to catabolize exogenous ethanol, resulting in the prominent decline of the ethanol level in the medium. The calluses of melon and peanut were also able to catabolize thanol but with lower efficiency. The other three calluses of carrot, soybean and rice did not catabolize ethanol but instead produced small to large amount of ethanol, resulting in the increase of the ethanol level in the media. It was also found that changing the balance between auxin and cytokinin could influence only the ethanol metabolism efficiency but could not change the metabolism patterns on ethanol of the cultured calluses. It can be concluded that, ethanol metabolism pattern of calluses in cultures is an innate physiological characteristic of the respective plant species.

Studies on steroidal plant growth regulator——27.Stereoselective construction of the side chain of brassinosteroid by employing a separated dialkylation and a tandem dialkylation of the pyranone moiety

A stereocontrolled construction of the side chain of brassinosteroid was developed via the separated dialkylation and the tandem dialkylation of the pyranone moiety as the key step.