Phyllostachys edulis (moso bamboo) rhizosphere increasing soil microbial activity rather than biomass

Purpose

Rhizosphere and fertilization might affect soil microbial activities, biomass, and community. This study aimed to evaluate the impacts of Phyllostachys edulis (moso bamboo) rhizospheres on soil nutrient contents and microbial properties in a moso bamboo forest with different fertilizer applications and to link soil microbial activities with abiotic and biotic factors.

Materials and methods

The experiment included three treatments: (1) application of 45% slag fertilizer (45%-SF); (2) application of special compound fertilizer for bamboos (SCF); and (3) the control without any fertilizer application (CK). Simultaneously, bulk soils and 0.5, 2.5, 4.5, and 6.5-year-old (y) bamboo rhizosphere soils were selected. Soil nutrient contents were analyzed. Microbial activities were evaluated based on the activities of soil enzymes including β-glucosidase, urease, protease, phosphatase, and catalase. The total microbial biomass and community were assessed with the phospholipid fatty acids (PLFAs) method.

Results and discussion

In the CK and SCF treatments, organic matter contents of rhizosphere soils were significantly higher than those of bulk soils. Soil β-glucosidase, urease, protease, phosphatase, and catalase activities in rhizosphere soils were higher than those of bulk soils, with the sole exception of β-glucosidase of 0.5 y rhizosphere soil in the 45%-SF treatment. Compared with the CK treatment, fertilizer applications tended to increase soil total PLFAs contents and changed soil microbial community. Moso bamboo rhizospheres did not significantly increase the total microbial biomass. In the SCF treatment, the Shannon index of bulk soil was significantly lower than those of rhizosphere soils.

Conclusions

Our results suggested that both rhizospheres and fertilizer applications could change the soil microbial community structures and that moso bamboo rhizosphere could increase microbial activity rather than biomass in the forest soils with different fertilizer applications.

     

毛竹PhcircRNA1的鉴定和调控通路分析

环状RNA(circRNAs)是一类经过反向剪切后,3′末端和5′末端共价结合形成的闭合环状单链非编码RNA,在环境胁迫下对植物生长发育有着重要调控作用。为探索circRNA在毛竹响应胁迫过程中的调控作用,本研究构建了circRNA-miRNA-mRNA调控通路。在分析毛竹的全转录组测序数据后,选择并鉴定了1个在紫外线胁迫（UV）和高温胁迫（42℃）下均差异表达的circRNA(PhcircRNA1),并利用生物信息学分析其调控的miRNA和靶基因。通过核糖核酸酶R(RNase R)法鉴定其转录的稳定性,并通过实时荧光定量PCR(qRT-PCR)方法分析了PhcircRNA1、靶miRNA(Ph-miR156)和靶mRNA的表达特征。本研究进一步选择GLR3.1(Glutamate Receptor–Like Gene 3.1)靶基因作为研究对象,观察毛竹水培苗根尖生长至1 cm后的circRNA-miRNA-mRNA表达调控趋势。结果表明,在UV胁迫和高温胁迫下,PhcircRNA1和靶mRNA表达量都有明显下降趋势,而miRNA表达量增高。在毛竹根尖细胞中,PhcircRNA1和G...     

毛竹4-香豆酸辅酶A连接酶基因家族鉴定及表达分析

4-香豆酸:辅酶A连接酶(4-coumarate:CoA ligase,4CL)基因是植物木质素、类黄酮和其他次生代谢产物合成的关键基因之一.为探究毛竹(Phyllostachys edulis)4CL基因的分子特征和表达模式,利用生物信息学方法对毛竹4CL同源基因进行鉴定,并对其基因结构、保守结构域和系统进化等进行全...     

Identification of fatty acid esters of pectenotoxin-2 seco acid in blue mussels (Mytilus edulis) from Ireland

Pectenotoxins from marine dinoflagellates of the genus Dinophysis are rapidly hydrolyzed by many shellfish to give pectenotoxin-2 seco acid, which isomerizes to 7-epi-pectenotoxin-2 seco acid. Three series of fatty acid esters of pectenotoxin-2 seco acid (PTX-2 seco acid) and 7-epi-PTX-2 seco acid were detected by LC-MS analysis of extracts from blue mussels (Mytilus edulis) from Ireland. The locations of the fatty acid ester linkages were identified by a combination of LC-MSn in positive- and negative-ion modes, LC-MS analysis of the products from reaction of the esters with sodium periodate, and NMR analysis of purified samples of the two most abundant ester derivatives. The 37-O-acyl esters of PTX-2 seco acid were the most abundant, followed by the corresponding 11-O-acyl esters, accompanied by low levels of the 33-O-acyl esters. The most abundant fatty acid esters in the fractionated sample were, in order, the 16:0, 22:6, 14:0, 16:1, 18:4, and 20:5 fatty acids, although a wide array of other PTX-2 seco acid fatty acid esters were also present at low levels.     

Identification of pinnatoxins and discovery of their fatty acid ester metabolites in mussels ( Mytilus edulis ) from eastern Canada

Pinnatoxins are a group of fast-acting cyclic imine toxins previously identified in shellfish from Asia, the southern Pacific, and northern Europe. In this work pinnatoxins were detected in mussels from locations across the eastern coast of Canada. Pinnatoxin G (6) was the major structural variant present, sometimes at levels >80 μg/kg, whereas much lower levels of pinnatoxin A (1) were detected in some samples. Increased concentrations were observed following base hydrolysis of extracts, leading to the discovery by LC-MS of a range of fatty acid esters of 6. Information on the structures of these acylated derivatives was provided through a series of mass spectrometric experiments, supported by partial synthesis, and it is proposed that the compounds are 28-O-acyl esters of 6. Although acyl esters of a range of other phycotoxins are known to form as metabolites in shellfish, this is the first report of their existence for this particular toxin class. The occurrence of pinnatoxins in North American shellfish further highlights the international distribution of these toxins.     

Nitrogen effects on total flavonoids,chlorogenic acid,and antioxidant activity of the medicinal plant Chrysanthemum morifolium

Chrysanthemum morifolium (Ramat.) has a long history of cultivation and use as a traditional medicine and tea plant in China. A greenhouse experiment with potted soil–quarz mixture studied the effects of nitrogen supply (0, 56, 112, 167, 224, 334, 501, 556, and 668 mg N kg^–1) on concentrations and ratios of total flavonoids and chlorogenic acid in the flowers of C. morifolium using spectrophotometric and HPLC methods. The antioxidant activity of the flowers was determined as the radical scavenging activities of hydroxyl, superoxide anion, and 2,2‐diphenyl‐1‐picrylhydrazyl hydrate (DPPH) free radicals. A high N supply decreased the concentrations of total flavonoids by 18%–35% and that of chlorogenic acid by 8%–60% compared to a low N‐supply rate. At the same time, increasing N supply significantly decreased the antioxidant activity of the flowers. The antioxidant activity of C. morifolium flowers was significantly positively correlated with the concentrations of total flavonoids and chlorogenic acid. We conclude that an N supply in excess of 300 mg (kg soil)^–1 will negatively affect the antioxidant activity and thereby reduce the quality of C. morifolium flowers.     

毛竹PheDof2转录因子克隆及表达分析

Dof蛋白是单锌指结构蛋白家族之一,在植物生长发育和非生物胁迫中发挥重要作用.为了探索Dof转录因子在毛竹中的功能及表达特征,本研究以毛竹实生苗为材料,采取反转录PCR(RT-PCR)技术克隆得到PheDof2基因的cDNA序列,对其进行生物信息学初步分析,并检测其在毛竹不同高度笋、花发育,及不同胁迫处理下的表达情况....     

Evaluation of antioxidant and prooxidant activities of bamboo Phyllostachys nigra var. Henonis leaf extract in vitro

Solvent-extracted bamboo leaf extract (BLE) containing chlorogenic acid, caffeic acid, and luteolin 7-glucoside was evaluated in vitro for free radical scavenging and antioxidant activities using a battery of test methods. BLE exhibited a concentration-dependent scavenging activity of DPPH radical. BLE prolonged the lag phase and suppressed the rate of propagation of liposome peroxidation initiated by peroxyl radical induced by 2,2'-azobis(2-amidinopropane dihydrochloride (AAPH) at 37 degrees C. BLE also prevented human low-density lipoprotein oxidation, mediated by Cu(2+), which was monitored by the lower formation of conjugated diene and fluorescence and a reduced negative charge of apo-B protein. Finally, BLE protected supercoiled DNA strand against scission induced by AAPH-mediated peroxyl radical. Prooxidant activity of BLE was seen in a Cu(2+)-induced peroxidation of structured phosphatidylcholine liposome, indicating catalytic peroxidation due to a relatively high reducing power of BLE. It was concluded that the BLE has both antioxidant activity and prooxidant activity; the antioxidant activity was attributed to free radical scavenging activity, and the prooxidant activity, albeit minor, resulted from the reducing power of plant phenolics in the presence of transitional metal ions.     

Antioxidant activity and diffusion of catechin and epicatechin from antioxidant active films made of poly(L-lactic acid)

Active membranes and food packaging containing antioxidants like catechin and epicatechin, combined with the use of materials made of biopolymers obtained from renewable sources, could create a novel alternative to reduce oxidation in food, pharmaceutical, and cosmetic products. Poly(94% L-lactic acid) films containing 1.28% catechin and 1.50% epicatechin were extruded in a pilot plant-scale extrusion machine. The diffusion kinetics of catechin and epicatechin into 95% ethanol at 20, 30, 40, and 50 °C and 50% ethanol at 40 °C displayed Fickian release behavior and diffusion coefficients between 0.5 and 50 × 10(-11) cm(2)/s. According to the Arrhenius equation, the energy of activation for the diffusion of catechin and epicatechin in the films was 110.43 and 98.92 kJ/mol, respectively. The antioxidant activity of the films was measured in methanol extracts containing 46.42 μg/mL of catechin and 57.52 μg/mL of epicatechin as 32.90 and 36.68% of scavenging the 2,2-diphenyl-1-picrylhydrazyl radical, respectively.     

Cu induced changes of ultrastructure and bioaccumulation in the leaf of Moso bamboo (Phyllostachys pubescens)

The effects of Copper (Cu) on growth of Moso bamboo (Phyllostachys heterocycla (Carr.) Mitford cv. pubescens) were investigated. The dry weight of Moso bamboo was inhibited and significant differences were evident under Cu stress as compared to the control (CK). Solution culture experiments indicated that Moso bamboo had a strong ability to accumulate Cu in shoots. Copper accumulation in the stem was stronger than the leaves; the stem/root ratio could reach 0.20 under Cu stress. The changes in cell walls, stomata, vacuoles, and starch grains content were observed via scanning electron microscopy and transmission electron microscopy. The ultrastructural analysis revealed that the excessive Cu concentrations caused deformities in the chloroplasts and transformation and even disappearance of endoplasmic reticulum. Moso bamboo as an experimental material serves as a new tool for remediation of heavy metal contaminated soils due to its metal tolerance and excessive biomass production.     

Phytochemical composition and antioxidant stability of fortified yellow passion fruit (Passiflora edulis)

Yellow passion fruit juice (PFJ, Passiflora edulis f. flavicarpa) is an important component of many tropical fruit beverages, but limited data exist on its antioxidant chemical composition and stability during processing and storage. PFJ fortified with ascorbic acid (450 mg/L) and sucrose (10%) was compared to a nonfortified control, and each was evaluated with and without vacuum deaeration to remove dissolved oxygen. Following pasteurization, juices were stored for 28 days at 37 degrees C to accentuate physicochemical changes. Pasteurization (85 degrees C for 30 min) resulted in minor changes to physicochemical attributes, but appreciable changes occurred during storage that resulted in termination of the study after 28 days. Oxygen control strategies proved to be ineffective for quality retention and indicated oxygen-independent reactions affecting juice color, phytochemical content, and antioxidant activity. Ascorbic acid and sucrose fortification had an overall preservation effect on total carotenoids, the former resulting in hyperchromic shifts in absorbance, indicating their chemoprotection. Pasteurization resulted in a 25% loss in l-ascorbic acid, which was completely destroyed after 14 days of storage; losses coincided with increased juice browning and formation of 5-hydroxymethylfurfural. Numerous polyphenolics were present in PFJ, and 16 of them were tentatively characterized on the basis of spectral similarities to known standards. Individually, polyphenolics increased during pasteurization, only to decline during storage at elevated temperatures. Antioxidant activity was measured in PFJ and in two subfractions (hydrophilic and lipophilic) after processing and storage, but antioxidant values were nonadditive. A significant chemical interaction affecting antioxidant capacity was found for hydrophilic juice components, but none was observed in the presence of lipophilic phytochemicals. Physicochemical attributes and overall quality of PFJ were retained following pasteurization but were significantly impacted by degradative reactions during accelerated storage.     

阔叶林改种毛竹(Phyllostachys pubescens)后土壤固氮细菌 nifH 基因多样性的变化

【目的】毛竹是喜氮植物,土壤氮素水平对毛竹生长至关重要。生物固氮是土壤氮素的重要来源,因此,探索阔叶林改种毛竹后土壤固氮细菌和土壤氮素的变化具有重要意义。【方法】选择立地条件相近的毛竹林(100多年前由阔叶林改种而来)和阔叶林,每种林地在东北坡向位置随机选择4个10 m×10 m标准样地,每个标准样地选取5个采样点,分层采集0—20 cm(表层)和20—40 cm(次表层)土壤样品,分析了土壤pH、有机碳、碱解氮、有效磷、速效钾和含水量等常规理化性质; 采用引物对AQER和PolF,以土壤总DNA为模板扩增了固氮细菌功能基因(nifH )片段,应用变性梯度凝胶电泳(DGGE)和实时荧光定量PCR(Real-time PCR),分析了固氮细菌群落结构、多样性以及丰度(nifH 基因拷贝数)变化; 通过基因克隆测序对土壤固氮细菌进行初步鉴定。【结果】阔叶林改种毛竹后土壤pH显著(P0.05)提高; 毛竹林土壤的含水量、碱解氮以及表层土壤的速效钾显著高于(P0.05)同层的阔叶林土壤,而有效磷则显著(P0.05)低于同层的阔叶林土壤。总体来说,阔叶林改种毛竹后土壤养分含量明显提高; 阔叶林土壤固氮细菌DGGE条带数以及多样性指数(Shannon-Wiener index)都高于毛竹林; 基于DGGE条带信息的聚类分析和主成分分析(PCA)结果表明,阔叶林和毛竹林区分为2个类群,而同一林分的不同土层之间差异较小; 实时荧光定量PCR结果显示,毛竹林土壤的固氮细菌 nifH 基因丰度显著(P0.05)高于阔叶林土壤; 通过克隆测序,14个阳性克隆分别属于2个不同的菌属,其中13个均为Bradyrhizobium,1个为Azohydromonas lata,条带序列与已知序列的相似度为93%~98%。【结论】阔叶林改种毛竹后土壤固氮细菌的种类减少,而功能基因丰度却明显增加; 土壤氮素水平明显提高,这可能是土壤固氮能力增强的结果。     

Identification, quantitative determination, and antioxidative activities of chlorogenic acid isomers in prune (Prunus domestica L. )

Neochlorogenic acid (3-CQA) and cryptochlorogenic acid (4-CQA), isolated from prune (Prunus domestica L.), were identified by NMR and MS analyses. In addition, the quantity of chlorogenic acid isomers in prune were measured by HPLC. These isomers, 3-CQA, 4-CQA, and chlorogenic acid (5-CQA), were contained in the ratio 78.7:18. 4:3.9, respectively. 4-CQA was identified and quantified in prune for the first time, and relatively high amounts of this isomer were characteristic. Antioxidative activities of the chlorogenic acid isomers, such as scavenging activity on superoxide anion radicals and inhibitory effect against oxidation of methyl linoleate, were also evaluated. Each isomer showed antioxidative activities which were almost the same.     

Soluble organic C and N and their relationships with soil organic C and N and microbial characteristics in moso bamboo (Phyllostachys edulis) plantations along an elevation gradient in Central Taiwan

Purpose

Moso bamboo (Phyllostachys edulis), an important economic crop, is distributed from low- to medium-elevation mountains in Taiwan. Bamboo is a fast-growing herbaceous species with an extensive rhizome structure. With the hypothesis that the characteristics of soil organic matter and microbes might change after long-term bamboo plantation, we investigated different fractions of organic C and N as well as soil microbial biomass and activities in five moso bamboo plantations along an elevation gradient in Central Taiwan.

Materials and methods

Five soil samples (top 10 cm of soil) were collected from each bamboo plantation (600, 800, 1,000, 1,200, and 1,400 m above sea level (asl)) in January 2011. Soil was processed and analyzed for soil total C and N contents, biologically available C, potentially mineralizable N, soil microbial biomass and soil respiration (CO₂). Two extraction methods (2 M KCl and hot-water extraction) were used to estimate soil soluble organic C and N (S_bOC and S_bON) and soil inorganic N (NH₄ ⁺ and NO₃ ^?) concentrations to evaluate the relationship with soil organic matter and microbe characteristics in bamboo plantations.

Results and discussion

Soil total C and N contents as well as soil microbial biomass and soil respiration (CO₂) of the bamboo plantations increased along the elevation gradient. Temperature changes along elevation contributed to such variations observed among the selected bamboo plantations. The S_bON in hot-water extracts was highest in the 1,200-m plantation, then in the 1,400-m plantation, and lowest in the low-elevation plantations (600, 800, and 1,000 m). However, S_bON in 2 M KCl extracts did not differ by elevation. The S_bON was strongly correlated with soil total N in both 2 M KCl and hot-water extracts, but only S_bON in hot-water extracts was strongly correlated with microbial biomass N and potentially mineralizable N. S_bOC was strongly correlated with soil total C content, microbial biomass C, and biologically available C in both 2 M KCl and hot-water extracts.

Conclusions

Soil total C and N, S_bOC and S_bON, and microbial biomass characteristics increased in the moso bamboo plantations with increasing elevation. No altitudinal difference in specific soil respiration (CO₂) rate suggested that the enhanced potentially mineralizable N and soil respiration (CO₂) in the high-elevation plantations were associated with increased microbial biomass rather than microbial activities.     

Profiling the chlorogenic acids and other caffeic acid derivatives of herbal chrysanthemum by LC-MSn

Four samples of herbal chrysanthemum have been profiled qualitatively by LC-MS5 to identify their component chlorogenic acids and partially characterize other caffeic acid derivatives. The chlorogenic acids were minor components, and the four samples varied markedly in profile. Three p-coumaroylquinic acids, three feruloylquinic acids, four caffeoylquinic acids, six dicaffeoylquinic acids, and two tricaffeoylquinic acids were detected, 13 for the first time from this source. Partial characterization of minor components suggested the presence of five caffeoyl-hexose esters and caffeic acid-4-beta-d-glucose that have not previously been reported from this source, and eight caffeoylquinic acid glycosides and 16 dicaffeoylquinic acid glycosides that have not previously been reported in nature. Succinic acid-containing chlorogenic acids and chlorogenic acids based on epi-quinic acid, previously reported in Chrysanthemum spp., were not detected in these samples.     

Separation and purification of tricin from an antioxidant product derived from bamboo leaves

Tricin (5,7,4'-trihydroxy-3',5'-dimethoxyflavone) occurs in its glycosidic form in rice bran and other grass species such as wheat, barley, and maize. Tricin is considered sufficiently safe for clinical development as a cancer chemopreventive agent, therefore it can be used for cancer prevention. This study established a new method for the preparation of tricin from bamboo leaves as an alternative to traditional methods such as chemical synthesis via the Baker-Venkata-Raman reaction between acetylsyringic acid and phloroacetophenone. Tricin was prepared from an antioxidant product that was derived from bamboo leaves (AOB) by extraction with aqueous ethanol. A concentrated solution of this product was obtained and then processed by polystyrene (AB-8) resin column chromatography and preparative high-performance liquid chromatography (HPLC) with 30% (v/v) acetonitrile in 1% (v/v) acetic acid as the mobile phase. The collected tricin-rich fraction was further sequentially purified by dialysis membrane separation and drowning-out crystallization methods. The purity was assessed by analytical HPLC with 25% (v/v) acetonitrile in 1% (v/v) acetic acid as the mobile phase, and the chemical confirmation was evaluated by infrared, mass, nuclear magnetic resonance, and ultraviolet spectroscopies. Tricin (3.09 g) was prepared from 174 g of a crude column chromatography fraction obtained from 5 L of AOB concentrated solution. The present method is appropriate for preparing quantities of pure tricin, which can be used for the quantification of tricin in various plant herbs and further for pharmaceutical/biomedical applications and evaluation.     

Isolation and characterization of undenatured chlorogenic acid free sunflower (Helianthus annuus) proteins

A method for obtaining sunflower protein (SFP) isolate, nondenatured and free of chlorogenic acid (CGA), has been developed. During the isolating procedure, the extent of CGA removal and protein denaturation was monitored. The defatted flour contained 2.5% CGA as the main phenolic compound. Phenolic compounds were removed by aqueous methanol (80%) extraction, before protein extraction at alkaline pH and diafiltration. Differential scanning calorimetry and solubility tests indicated that no denaturation of the proteins had occurred. The resulting protein products were biochemically characterized, and the presence of protein-CGA complexes was investigated. SFPs of the studied variety were found to be composed of two main protein fractions: 2S albumins and 11S globulins. In contrast to what has been previously reported, CGA was found to elute as free CGA, not covalently associated to any protein fraction.     

Recovery mechanism of the antioxidant activity from carnosic acid quinone,an oxidized sage and rosemary antioxidant

A solution of carnosic acid quinone, which is a radical chain-termination product having no antioxidant activity in the antioxidant reaction of carnosic acid, recovers potent antioxidant activity upon standing. The HPLC analysis of an aged solution of carnosic acid quinone revealed that several antioxidants are produced in the solution. From the time-course and quantitative analyses of the formation of the products and their structural analysis, an antioxidant mechanism from carnosic acid quinone is proposed that includes a redox reaction of carnosic acid quinone in addition to the isomerization to lactone derivatives. In the first stage of antioxidation, carnosic acid, the reduction product from carnosic acid quinone, contributes to the potent antioxidant activity of the solution. This proposed mechanism can explain one of the reasons for the strong antioxidant activity of the extract of the popular herbs sage and rosemary.     

The antioxidant and chlorogenic acid profiles of whole coffee fruits are influenced by the extraction procedures

Commercial whole coffee fruit extracts and powder samples were analyzed for chlorogenic acids (CGA), caffeine and antioxidant activities. CGA and caffeine were characterized by LC-MS(n) and HPLC accordingly, and quantified by UV absorbance. ORAC, HORAC, NORAC, SORAC and SOAC (antioxidant capacities) were assessed. Three caffeoylquinic acids, three feruloylquinic acids, three dicaffeoylquinic acids, one p-coumaroylquinic acid, two caffeoylferuloylquinic acids and three putative chlorogenic lactones were quantified, along with a methyl ester of 5-caffeoylquinic acid (detected in one sample, the first such report in any coffee material). Multistep whole coffee fruit extracts displayed higher CGA content than single-step extracts, freeze-dried, or air-dried whole raw fruits. Caffeine in multistep extracts was lower than in the single-step extracts and powders. Antioxidant activity in whole coffee fruit extracts was up to 25-fold higher than in powders dependent upon the radical. Total antioxidant activity of samples displayed strong correlation to CGA content.     

Erratum to: Soluble organic C and N and their relationships with soil organic C and N and microbial characteristics in moso bamboo (Phyllostachys edulis) plantations along an elevation gradient in Central Taiwan

Journal of Soils and Sediments -