Organic Acids Secreted from Plant Roots under Soil Stress and Their Effects on Ecological Adaptability of Plants

[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided theoretical basis for improving the adaptability of plants to a variety of stress conditions.The results showed that,under nutrient and water stress,the content of organic acids secreted from plant roots increased significantly as a common active adaptive response.Organic acids could improve the activities of a variety of antioxidant enzymes,contents of osmotic regulatory substances,contents of chlorophyll and photosynthesis levels,promote nutrient absorption and transportation in plants,and ultimately contribute to plant growth and biomass accumulation,reduce the toxicity of stress conditions to plants and improve the stress resistance and adaptability of plants.

Effects of Music Acoustic Frequency on Indoleacetic Acid in Plants

[Objective] The aim was to study the effects of music acoustic frequency on the contents of indoleacetic acid（IAA） in 6 species of vegetables.[Method] Music acoustic frequency group and control group were designed to determine the related growth indicators of unified managed 6 species of vegetables regularly.The contents of indoleacetic acid were detected by the High Performance Liquid Chromatography（HPLC）.[Result] The music acoustic frequency had significantly increased the contents of indoleacetic acid in 6 species of vegetables,which were significantly higher than that in the control.[Conclusion] The music acoustic frequency could stimulate the IAA secretion in plants.

Real-Time PCR Technique and Its Application in Quantification of Plant Nucleic Acid Molecules

Real-time PCR is a closed DNA amplification system that skillfully integrates biochemical, photoelectric and computer techniques. Fluorescence data acquired once per cycle provides rapid absolute quantification of initial template copy numbers as PCR products are generated. This technique significantly simplifies and accelerates the process of producing reproducible quantification of nucleic acid molecules. It not only is a sensitive, accurate and rapid quantitative method, but it also provides an easier way to calculate the absolute starting copy number of nucleic acid molecules to be tested. Together with molecular bio-techniques, like microarray, real-time PCR will play a very important role in many aspects of molecular life science such as functional gene analysis and disease molecular diagnostics. This review introduces the detailed principles and application of the real-time PCR technique, describes a recently developed system for exact quantification of AUX/IAA genes In Arabidopsis, and discusses the problems with the real-time PCR process.

Low-Molecular-Weight Aliphatic Acids in Soils Incubated with Plant Residues Under Different Moisture Conditions

Incubation experiments were conducted to investigate the dynamics of low- molecufar-weight aliphatic acids in two andosols with and without plant materials. Results showed that amount of low- molecular-weight aliphatic acids in soils alone varied considerably with water regime under which the soil was incubated,duration of incubation and soil organic matter content, ranging from 257-860 pmol kg-1 soil I of which 19%～33% was in free state. Incorporation of plant materials increased greatly both the amount and number of members of low- molecular- weight aliphaticacidst and also the proporticn of low-molec "far-weight aliphatic acids occurred in free state. Generally, among these aliphatic acids detected, acetic, propionic, glyoxalic and formic acids were predominant.

Rapid and sensitive method for determining free amino acids in plant tissue by high-performance liquid chromatography with fluorescence detection

This paper describes a reliable and rapid method for the complete separation and quantitation of twenty-five amino acids typically found in plants, based on reversed phase high-performance liquid chromatography–linked fluorescence detector using a 150×4.6 mm Zorbax Eclipse AAA column. Plant tissue free amino acids(FAA)were extracted by ultrasonication with 5%(v/v) aqueous trifluoroacetic acid followed by ultrafiltration of extracts.The following analysis of amino acids was performed through programmed precolumn derivatization with orthophthalaldehyde and 9-fluorenylmethyl chloroformate reagents and efficient elution of derivatives within 26 min using binary gradient scheme. The method was validated over a concentration range of 4.5–450 μmol L^(-1)(μM).Separation analysis showed good selectivity(resolution>1.5) for most amino acids. The average repeatability(RSD%, relative standard deviation) of the analysis at seven calibration concentrations was below 4% and ranged from 1.13% to 12.04%. The intra-day mean coefficient of variation at two concentrations(22.5 and 90 μM) was within 2%, and the intermediate precision was less than 4%. The limits of detection were between 0.012 and 6.68 μM. The coefficients of determination(R2) of the linear calibration curves were from 0.9989 to 0.9999.When the method was applied to plant samples, the FAA recoveries at two spiked levels(25 and 100 μM) ranged from 67.0% to 108.9% with an average of 94.4%, and the precision was 0.26%–12.31% RSD. A specific application combining this method with optimized extraction and interference removal procedures was successfully used to determine the FAA pools in different plant tissues. Finally,a PLS-DA multivariate statistics model was validated for the classification of three plant species according to their FAA profiles.

Key Organic Acids in Indigenous Plants in Thailand

Organic acids had various health benefits such as citric acid can inhibit stone formation and break up beginning of small kidney stone. On the other hand, some organic acid showed negative health effects such as oxalic acid acts as anti-nutrients and can cause kidney stone. Most of Thai indigenous plants had sour taste;however general people believed that sour taste of plants could contain high ascorbic acid. In addition, there is limit report of organic acids and ascorbic acid in Thai indigenous plants. This study determined organic acids, ascorbic acid, pH, and total acidity in indigenous plants. Forty samples of 29 types of indigenous plants were analyzed. Results showed that young leaves of Cratoxylum formosum found the highest succinic acid (2454 ± 91 mg/100g fresh weight, FW) and high ascorbic acid (142 ± 35 mg/100g FW). Fruits of Antidesma ghaesembilla had high citric acid levels (5161 ± 109 mg/100g FW) but contained very low ascorbic acid (2 mg/100g FW). The sum of organic acids had significant and inverse correlations with pH (r = -0.680) and positive with total acidity (r = 0.672) but was not significantly correlated for ascorbic acid (r = 0.536). The sour taste of plants could derive from the sum of organic, citric, and formic acids, but not other organic and ascorbic acids. Against traditional belief, plants having a strong sour taste may not contain significantly high amounts of ascorbic acid.

Relative sensitivities of woody plants to acid deposition in south areas of China

Relative sensitivities of 30 species of common woody plants to simulated acid rain with pH values of 2.0, 2.5, 3.0, 3.5, 4.5 and control were studied. The results showed that 6 species of these plants were sensitive to simulated acid rain. The moderate included 18 species. The resistant included 6. Relative sensitivities to ambient acid rain and air pollutants and visible injury degree of 30 species of common woody plants in Chongqing City were investigated. Results showed that 6 species with foliage lesion rate at above 10 percent were sensitive, that 6 species with no lesion were resistant and that other 18 species with lesion at 10 percent below were moderate. Other 7 cities (Guiyang, Zunyi, Duyun, Changsha, Zhuzhou, Liuzhou and Guilin City) were also investigated and results were consistent with those of Chongqing City. The experimental and investigated results showed relative sensitivities and visible injury degree of woody plants to simulated acid rain were consistent with those of the woody plants to ambient acid rain and air pollutants. The sensitive plants may be used as bioindicators to acid rain or air pollutants. The resistant species can be introduced to acid rain and air pollution areas to substitute damaged sensitive plants in order to improve environment.

Antimicrobial activity of kojic acid from endophytic fungus Colletotrichum gloeosporioides isolated from Sonneratia apetala,a mangrove plant of the Sundarbans

Objective: To isolate and evaluate the antimicrobial activity of the active principle(s) from the ethyl acetate(EtOAc) extract of endophytic fungus Colietotrichum gloeosporioides(C.gloeosporioides) isolated from Sonneratia apetala. Methods: Water agar technique was used to isolate the fungus, and both microscopic and molecular techniques were used for identification of the strain. Potato dextrose broth was used to grow the fungus in large-scale. Reversed-phase preparative HPLC analysis was performed to isolate the major active compound, kojic acid. The EtOAc extract and kojic acid were screened for their antimicrobial activity against two Grampositive and two Gram-negative bacteria as well as a fungal strain using the resazurin 96-well microtitre plate antimicrobial assay. Results: The fungus C. gloeosporioides was isolated from the leaves of Sonneratia apetala. Initial identification of the fugal isolate was carried out using spore characteristics observed under the microscope. Subsequently, the ITS1-5.8 S-ITS2 sequencing was employed for species-level identification of the fungus C. gloeosporioides. Five litres of liquid culture of the fungus produced approximately 610 mg of a mixture of secondary metabolites.Kojic acid(1) was isolated as the main secondary metabolite present in the fungal extract, and the structure was confirmed by 1 D, 2 D NMR and mass spectrometry. The EtOAc extract and compound 1 exhibited considerable antimicrobial activity against all tested microorganisms.Whilst the minimum inhibitory concentration(MIC) values from the EtOAc extract ranged between 2.4×10^(-4)mg/mL and 2.5 mg/mL, those of kojic acid(1) were between 0.125 mg/mL and1 mg/mL. The EtOAc extract and kojic acid(1) were most active against Pseudomonas aeruginosa(MIC = 2.4×10^(-4). mg/mL) and Micrococcus luteus(MIC = 0.125 mg/mL), respectively. Conclusions:The results revealed that the endophytic fungus C. gloeosporioides could be a good source of commercially important kojic acid, which exhibited antimicrobial properties.

Chlorogenic Acid Metabolism:The Evolution and Roles in Plant Response to Abiotic Stress

During the evolution,plants acquired the ability to synthesize different phenylpropanoid compounds like chlorogenic acid(CGA),which plays vital roles in resistance mechanisms to abiotic stresses.These environmental factors,including heavy metal,cold,heat,ultraviolet(UV)light,drought,and salinity affect the plant physiological processes,resulting in massive losses of agriculture production.As plants evolve from green algae to bryophytes,ferns,gymnosperms and angiosperms,phenylpropanoids are produced and accumulated in different tissues,giving the plant the capacity to counteract the harmful effects of the adverse environments.Studies have been performed on the metabolic evolution of rosmarinic acid,flavonoids and lignin,showing that the biosynthesis of phenylpropanoids begins in green algae until the emersion of genes found in angiosperms;however,the evolution of the CGA pathway has not yet been reviewed.We hypothesize that CGA could also be synthesized from algae to angiosperms.In the present review,the evolutionary analysis of CGA pathway and the function of this compound in plant tolerance to abiotic stresses are summarized.Bioinformatics analyzes were carried out on CGA-related genes across 37 plant species and revealed that the metabolic pathway starts in algae and gradually increases until it becomes complete in angiosperms.The key genes exhibited different expression patterns in stress and plant tissues.Interestingly,some genes accumulated rapidly during evolution and were more sensitive to environmental stresses,while others appeared only later in angiosperms.Further studies are needed to better understand the evolution of the CGA metabolic pathway in plants under environmentally stressed conditions.

Response of 14C-Salicylic Acid to Heat Stress After Being Fed to Leaves of Grape Plants

An experiment was conducted to investigate the response of salicylic acid as a second messenger to the heat stress in grape plants. For this purpose, all leaves of grape (Vitis vinifera×V. labrussa L. cv. Jingxiu) plants were removed except the 3rd, 4th, 5th, 6th, and 7th ones. The 5th leaf was fed with C-SA, and the 4th and 6th leaves were exposed to high 14 temperature at 40±0.5°C. It was observed that more C-SA transported out from the 5th leaf and the distribution of C-SA 14 14 in each organ of plant altered in response to heat stress. The accumulation of C-SA in both the 4th and 6th leaves being 14 exposed to high temperature was at least three times higher than that in control. The distribution of C-SA in other distal 14 leaves (the 3rd and 7th leaf) decreased, but more C-SA accumulated in stems adjacent to the 4th or 6th leaf exposed to 14 high temperature. In addition, there was more C-SA being transported upwards or downwards while the 4th and 6th 14 leaves were exposed to high temperature respectively. Therefore, our results suggested that SA was closely involved in signal transduction of heat stress in grape plants. However, the ratio of C radioactivity assayed after SA being extracted 14 to that of direct assay with apparatus was more than 70%, which indicated about 30% C was lost or catabolized during 14 transportation.

Effect of Dominant Semi-Dwarf Gene on Plant Height and Its Related Traits and Sensitivity to Gibberellic Acid in Rice

Six pairs of tall and dwarf near-isogenic lines derived from a dominant semi-dwarf mutant （Y98149） were selected to study height expression and sensitivity to gibberellic acid （GA3）. The lengths of the 4-5th internode, the 3rd, 2nd, 1st internodes from the top and the panicle length in the six dwarf near isogenic lines were 97.2%, 53.3%, 65.1%, 61.9% and 94.7% of those in the six tall ones, respectively, indicating that the dominant semi-dwarfing gene significantly inhibited the internode elongation. Moreover, Y98149 （mutant type） was more sensitive to GA3 than Y98148 （wild type）, and had a lower GA3 concentration in plant, about 78% of Y98148.

Effects of Plant-derived Humic Acid Organic Fertilizer on Selenium Content of Rice in Northern Guangxi

This study was to find out the suitable application amount of plant-derived humic acid organic fertilizer for selenium-rich rice production in northern Guilin area by applying the fertilizer at different amounts.The results showed that plant-derived humic acid organic fertilizer could effectively activate selenium in selenium-rich soil,and then promote the uptake of selenium by rice.With costs,selenium enrichment and rice yield as the main evaluation indicators,A4 was chosen as the best treatment,that is,the application of 4 500 kg/hm^2 of plant-derived humic acid organic fertilizer as base fertilizer could achieve the best benefit.

Combined Effects of Plant Sterols with Low Ratio of n-6/n-3 Polyunsaturated Fatty Acids against Atherosclerosis in ApoE–/–Mice

The effects of low ratio of n-6/n-3 polyunsaturated fatty acids(PUFA)have been clarified against atherosclerosis.Increasing evidence indicated that plant sterols(PS)have a significant cholesterol-lowering effect.This study explored the effects of PS combined with n-6/n-3(2:1)PUFA on atherosclerosis and investigated the possible mechanism.In ApoE−/−mice,the milk fat in high fat diets was replaced with n-6/n-3(2:1)PUFA alone or supplemented with 6%PS for 16 weeks.Results demonstrated that PS combined with PUFA exerted commentary and synergistic effects on ameliorating atherosclerosis,improving lipid metabolism and lipid deposition in liver,and alleviating inflammatory response.These changes were accompanied with decreased serum TC,TG,LDL-C and increased fecal cholesterol efflux,as well as the lower inflammatory cytokine CRP,IL-6,TNF-α.It is suggested that the underlying mechanism of PS combined with n-6/n-3(2:1)PUFA promoting the fecal cholesterol efflux may be mediated by liver X receptorα/ATP-binding cassette transporter A1 pathway.

Effect of Different Acids on the Scale in Pipelines of Linz-Donawitz (LD) Plant (Steel Making Process)

In this report we present the effect of different acids on the scales taken from LD plant. The main aspect of the problem is to find a suitable concentration and type of acid to reduce/remove the deposition of scale in the pipeline. The analysis is carried out using a combination of suggestions dictated by experimental evidence and suitable mathematical techniques. Result reveals that 5% solution of Hydrochloric Acid is most effective to dissolve the scale in a specified time at room temperature. The order of effectiveness to dissolve the scale deposits is HCL > HNO3 > H3NSO3> H2C2O4 > H2SO4. But when it comes to the corrosion in the pipe the order of corrosion caused by acids is HCL > H3NSO3 > HNO3. So, when we consider both the results HNO3 is the most suitable acid with respect to both scale deposition and corrosion of the pipelines. Predictions of the data are compared with experiments finding a remarkable agreement with the available data.

Study on Addition Amount of Lactic Acid Bacteria and Cellulase in Mixed Silage of Potato Plants

[Objectives]This study was conducted to investigate the appropriate addition amounts of lactic acid bacteria and cellulase in the mixed silage of potato plants,so as to provide a basis for the rational use of potato plants.[Methods]Fresh potato(Solanum tuberosum)seedling plants,watermelon(Citrullus lanatus)plants,and melon(Cucumis melo)plants were selected as raw materials for silage,each of which was added at a ratio of 32%,and 4%of brown flour was added additionally.On this basis,an L 9(32)orthogonal experiment was designed to investigate the effects of the amount of lactic acid bacteria(10,20,30 g/kg)and the amount of cellulase(5,10,15 g/kg)on the experimental results with sensory evaluation score as an investigation index.[Results]With the increase of the amount of lactic acid bacteria and the amount of cellulase,the sensory evaluation score of silage increased,and it was the highest when the amount of lactic acid bacteria added was 20 g/kg and the amount of cellulose was 10 g/kg.With the increase of the amounts of lactic acid bacteria and cellulase added,ammonia nitrogen showed a decreasing trend,and the pH and ammonia nitrogen were the lowest when the amount of lactic acid bacteria added was 20 g/kg and the amount of cellulose was 10 g/kg.[Conclusions]This study provides a theoretical basis for the rational use of effective ingredients and nutrients in potato plants and the development of new feed resources.

Plant Growth Promoting Rhizobacteria Having 1-Aminocyclopropane-1-Carboxylic Acid Deaminase to Induce Salt Tolerance in Sunflower (<i>Helianthus annus L.</i>)

Soil salinity badly affects agriculture productivity through accumulation of salts in upper layers of soils. The harmful effects of salts in arable lands have influenced modern as well as ancient civilizations. A pot study was carried out to test the performance of two PGPR isolates (KS 8, KS 28) on sunflower (SMH-0917) under different salinity levels (8, 10 and 12 dS·m-1). These salinity levels were developed by adding calculated amount of salts (NaCl, Na2SO4, CaCl2 and MgSO4) with ratio of 3:4:2:1. The bacterial strains KS 8 and KS 28 were applied separately in two treatments while third treatment was co-inoculation (KS mix). Completely randomized experimental design (CRD) was used and data were collected at flowering stage about pre-decided plant growth parameters (plant height, shoot dry weight and root dry weight). The bacterial isolate KS 8 showed an increase of 26, 102% and 83% in plant height, shoot dry weight and root dry weight at EC 8 dS·m-1, while this improvement was 67%, 163% and 296% at EC 10 dS·m-1, however an increase of 100%, 74% and 382% was recorded over control respectively at EC 12 dS·m-1. Similarly isolate KS 28 exhibited an increase of 14%, 69% and 54% in plant height;shoot dry weight and root dry weight at EC 8 dS·m-1, whereas this improvement was 56%, 163% and 188% at EC 10 dS·m-1, while an increase of 60%, 41% and 282% was registered respectively over control at EC 12 dS·m-1. The increase due to mixture treatments was 4%, 41% and 16% in plant height, shoot dry weight and root dry weight at EC 8 dS·m-1, while an increase of 33%, 57% and 100% at EC 10 dS·m-1, whereas an improvement of 53%, 33% and 164% respectively was noted at EC 12 dS·m-1 over un-inoculated. The isolate KS 8 performed better than KS 28 and mixture treatment. These two PGPR strains could be used to mitigate the adverse impact caused by salinity stress on sunflower.

A novel chorismate mutase effector secreted from root-knot nematode Meloidogyne enterolobii manipulates plant immunity to promote parasitism

Meloidogyne spp.is an economically important plant-parasitic nematode distributed worldwide.To fight with host immune system for successful parasitism,plant parasitic nematodes secrete effectors to promote infection.In this study,we identified one chorismate mutase(CM)effector from M.enterolobii,named Me-CM.Spatial and temporal expression assays exhibited Me-cm is expressed in esophageal glands and up-regulated at parasitic-stage juveniles.Me-CM affects the pathogenicity of M.enterolobii based on the reduced infection rate,number of galls,egg masses,eggs per mass and multiplication rate collected from RNA silencing experiments.We showed that Me-CM localized in the cytoplasm and nucleus of plant cells and decreased the expression level of the marker gene PR1 of salicylic acid(SA)pathway.Besides,constitutive expression of Me-cm in Arabidopsis thaliana significantly reduced salicylic acid concentration.These results suggested that M.enterolobii may secrete effector Me-CM to fight with plantimmunesystemsvia regulating SA signaling pathway when interacting with host plants,ultimately facilitating parasitism.

A review: effect and mechanism of plant extracts rich in polyphenols on reducing uric acid activity

Hyperuricemia is a metabolic condition caused by the increase of uric acid level in the body,which can lead to gout,kidney disease,cardiovascular disease,hypertension and diabetes.In recent years,the incidence rate of hyperuricemia has been increasing and gradually becoming younger.Allopurinol and febuxostat are commonly used drugs to reduce the level of uric acid in the body.Although these drugs have good curative effect,they can produce adverse reactions.Therefore,it has been the focus of attention to find appropriate treatment and new drugs to reduce serum uric acid level.Natural plants have become the source of new drugs for their multiple biological activities,strong efficacy and minimal side effects.More and more studies have shown that natural plant extracts rich in phenols,flavonoids and other active components can significantly reduce the level of uric acid,and improve the complications caused by high uric acid.In this paper,hyperuricemia related diseases,functional plants rich in polyphenols with the effect of reducing uric acid and the mechanism of their active components were reviewed.

Research and Applicationon Plant Hormone--Abscisic Acid, ABA

Abscisic Acid (ABA), along with ethylene, gibberellins, cytokinins and auxins, is regarded as five kinds of important plant hormone. ABA was first isolated from cotton bud by Addcott Ohhuma’s group in 1963. Until 1965, its plane structure was determined. It was formally named as Abscisic acid in "the International Conference of Plant Regulator" in 1967. Scientists all over the world have made a long-term unremitting effort

A PRELIMINARY STUDY ON THE INTRODUCTION OF DESCURAINIA SOPHIA, AN OIL PLANT SPECIES FOR INDUSTRIAL USES

The authors had collected some cruciferous oil plants with high linolenic acid content in Sichuan Province. The result of fatty acid analysis had shown that Malcolmia africrma (L.) R. Br. and Arabis hirsuta (L.) Scop, have a higher linolenic acid content of 57.37% and 51.38% respectively . Thus they are worthy for further study. Descurainia sophia (L.) Webb. ex Prantl, especially that collected from Hongyuan County, has a high seed oil content of 44.17% , a linolenic acid content of 40.9 % and a high seed yield of 1 264.5 kg/hm2 . It is suggested that this oil plant species can be introduced for industrial utilization.