Soybean(Glycine max)rhizosphere organic phosphorus recycling relies on acid phosphatase activity and specific phosphorusmineralizing-related bacteria in phosphate deficient acidic soils

Bacteria play critical roles in regulating soil phosphorus(P) cycling. The effects of interactions between crops and soil P-availability on bacterial communities and the feedback regulation of soil P cycling by the bacterial community modifications are poorly understood. Here, six soybean(Glycine max) genotypes with differences in P efficiency were cultivated in acidic soils with long-term sufficient or deficient P-fertilizer treatments. The acid phosphatase(AcP) activities, organic-P concentrations and associated bacterial community compositions were determined in bulk and rhizosphere soils. The results showed that both soybean plant P content and the soil AcP activity were negatively correlated with soil organic-P concentration in P-deficient acidic soils. Soil P-availability affected the ɑ-diversity of bacteria in both bulk and rhizosphere soils. However, soybean had a stronger effect on the bacterial community composition, as reflected by the similar biomarker bacteria in the rhizosphere soils in both P-treatments. The relative abundance of biomarker bacteria Proteobacteria was strongly correlated with soil organic-P concentration and AcP activity in low-P treatments. Further high-throughput sequencing of the phoC gene revealed an obvious shift in Proteobacteria groups between bulk soils and rhizosphere soils, which was emphasized by the higher relative abundances of Cupriavidus and Klebsiella, and lower relative abundance of Xanthomonas in rhizosphere soils. Among them, Cupriavidus was the dominant phoC bacterial genus, and it was negatively correlated with the soil organic-P concentration. These findings suggest that soybean growth relies on organic-P mineralization in P-deficient acidic soils, which might be partially achieved by recruiting specific phoCharboring bacteria, such as Cupriavidus.

Mammalian-like Purple Acid Phosphatases in Plants

Introduction Purple acid phosphatases （PAPs） comprise of a family of binuclear metal-containing hydrolases, some members of which have been isolated and characterized from animal, plant and fungal sources . PAPs not only catalyze the hydrolyses of a wide range of phosphate esters and anhydrides under acidic reaction conditions, but also catalyze the generation of hydroxyl radicals in a Fenton-like reaction, by virtue of the presence of a redox-active binuclear metal center. Inmammals,

Phosphorus Starvation-induced Expression of Leaf Acid Phosphatase Isoforms in Soybean

Leaf acid phosphatase (APase) activities of 274 soybean genotypes were surveyed under field conditions with two levels of P supplies, and a nutrient solution culture experiment with eight selected genotypes was subsequently conducted under greenhouse conditions to further characterize APase activity and its isoform expression induced by P starvation. Results from the field experiment showed that there was a great genotypic variation for leaf APase activity among the tested soybean genotypes from different origins, and APase activity in many of the tested genotypes (about 60%) was generally increased in the treatment without P fertilizer addition. Results from the nutrient solution culture experiment showed that APase activity in all the eight tested genotypes was generally enhanced by P starvation. Six isoforms of APases were detected in isoelectric focusing gels with samples from both young and old leaves. The activity of all the six isoforms was increased by P starvation, but no new APase isoform was induced. Our results suggest that leaf APase activity could serve as an enzymatic indicator of P starvation for soybean; the increase in leaf APase activity under low P stress was mainly caused by the increase in the activity of existing isoforms but not by the induction of new isoforms.

Research on Sex and Tissue Differences in Isozymic Phenotype of Varicorhinus macrolepis through Isozyme Electrophoresis

Polyacrylamide gel electrophoresis (PAGE) and biochemical staining method were used in this study for the analysis on malate dehydrogenase (MDH,E.C. 1.1.1.37) isozymes zymogram in 11 different types of tissues of male and female Varicorhinus macrolepis. It had been found for the first time that the phenotype of malate dehydrogenase (MDH),acid phosphatase (ACP) and superoxide dismutase (SOD) showed difference between male and female V. macrolepis,and there was no difference among different individuals in the same sex. Therefore,the electrophoresis band of malate dehydrogenase,acid phosphatase and superoxide dismutase could be used as an indicator for the identification of gender and tissues of V. macrolepis,which would provide basic data for the developmental genetics,variety improvement and directed breeding of V. macrolepis groups,thus facilitating the development and protection of this valuable fish species.

Analysis on Activity of Immunity-related Enzymes in First Familiar Generation and Self Cross F1 of Platichthys stellatus Pallas

[Objective] The aim was to study the activity of immunity-related enzymes in each tissue of self cross F1 of Platichthys stellatus Pallas and first familiar generation of P.stellatus ♀×Verasper variegates ♂.[Method] The activity difference of three important non-specific immunity-related enzymes：acid phosphatase （ACP）,alkaline phosphatase （AKP） and superoxide dismutase （SOD） existed in muscle,liver,spleen and intestine of first familiar generation and self cross F1 of P.stellatus was compared.[Result] The activity of ACP and AKP in muscle,liver and intestine of first familiar generation was higher than that of self cross F1,while the activity of ACP and AKP in liver of first familiar generation showed no significant difference with that of self cross F1; the SOD activity decreased significantly in tissues expected for muscle.[Conclusion] The result had provided theoretic basis for the breeding of P.stellatus.

Ultracytochemical Localization of Acid Phosphatase in Nucellar Cells of Wheat During Degeneration

The distribution of acid phosphatase activity in nucellar cells of wheat ( Triticum aestivum L.) during degeneration has been studied using the lead precipitation method at the electron microscopic level. Acid phosphatase was localized in the slightly condensed nuclear chromatin in nucellar cells without any sign of ultrastructural degeneration. As the nucellar cells started degenerating, the enzyme activity in the cell was observed, in the order from small vacuoles to cell walls, mitochondria, plastids and endoplasmic reticulum. Enzyme activity was the highest in most components of the nucellar cells adjacent to the embryo sac where the degeneration of nucellar cells was the strongest, but it was not observed in the nuclei of the degenerated nucellar cells. The results indicated that the degeneration of nucellar cells was a progressive and orderly process and supported that the degeneration of nucellar cells was a programmed cell death.

The Study on the Localization of Acid Phosphatase Activity During Spermiogenesis in Chinese Mitten-Handed Crab,Eriocheir sinensis

Ultrastructural cytochemical techniques and electron microscopy were used for localization of acid phosphatase activity during spermiogenesis in Eriocheir sinemsis. The results showed that： Acid phosphatase was synthesized in the endoplasmic reticulum in the early spermatids. The acid phosphatase was found gradually in nucleus, the membrane of acrosomal vesicle, the cytoplasmic region and the acrosomal tubule. And then the reaction product particles became thicker during the spermiogenesis. In the mature sperm, acid phosphatase was localized in the percutor organ slightly, but it was massive and compact in the acrosomal tubule.

Soil Enzyme Activity Changes in Different-Aged Spruce Forests of the Eastern Qinghai-Tibetan Plateau

Activities of selected soil enzymes (invertase, acid phosphatase, proteinase,catalase, peroxidase and polyphenoloxi-dase) were determined under different spruce forests withrestoration histories of 5, 13, 18, 23, 27 years and an old growth forest over 400 years old in theeastern Qinghai-Tibetan Plateau, China, and their possible use as indicators of ecosystems healthwere analyzed. Plots 10 X 10 m with 4 replications were established to investigate three hypotheses:soil enzyme activities a) would increase with the restoration process; b) would be greater insurface soils than at lower depths; and c) would be correlated to selected physicochemicalproperties. Results showed that as the forests developed after restoration, invertase and peroxidaseactivities usually increased up to the 23 year point. Also soil enzyme activities were associatedwith surface soils and decreased with depths, suggesting that in earlier restoration stages surfaceaddition of organic fertilizer to soils might be more effective than additions at depth. In the 0-20cm soil, there were significant correlations (P < 0.01 or < 0.05) between some soil enzymeactivities and some selected chemical properties. Therefore, temporal changes in enzyme activitiesshould be included as an indicator when evaluating sustainable forest management practices.

Effects of lead exposure on histological structure and antioxidant capacity in the cerebellum of 30-day-old mice

The current study sought to observe the effects of lead on histological structure and antioxidant capacity in 30-day-old mice.Spectrophotometry was used to detect the activities of superoxide dismutase,catalase,alkaline phosphatase,acid phosphatase and the malondialdehyde content.The results revealed that Purkinje cells in the lead-exposed group exhibited obvious pyknosis,atrophy and a decrease in overall number.Granular cells exhibited a disorderly arrangement,and were reduced in number.Administration of lead decreased the activities of superoxide dismutase,catalase,alkaline phosphatase and acid phosphatase,while malondialdehyde content increased.Two-way analysis of variance indicated that dose contributed more to lead-induced cerebellum damage than treatment time.The present study demonstrated that lead exerted strong effects on histological structure and inhibited antioxidant capacity of the cerebellum in 30-day-old mice.

Phytate:impact on environment and human nutrition.A challenge for molecular breeding

Phytic acid (PA) is the primary storage compound of phosphorus in seeds accounting for up to 80% of the total seed phosphorus and contributing as much as 1.5% to the seed dry weight. The negatively charged phosphate in PA strongly binds to metallic cations of Ca, Fe, K, Mg, Mn and Zn making them insoluble and thus unavailable as nutritional factors. Phytate mainly accumulates in protein storage vacuoles as globoids, predominantly located in the aleurone layer (wheat, barley and rice) or in the embryo (maize). During germination, phytate is hydrolysed by endogenous phytase(s) and other phosphatases to release phosphate, inositol and micronutrients to support the emerging seedling. PA and its derivatives are also implicated in RNA export, DNA repair, signalling, endocytosis and cell vesicular trafficking. Our recent studies on purification of phytate globoids, their mineral composition and dephytinization by wheat phytase will be discussed. Biochemical data for purified and characterized phytases isolated from more than 23 plant species are presented, the dephosphorylation pathways of phytic acid by different classes of phytases are compared, and the application of phytase in food and feed is discussed.

Olive leaf extract inhibits lead poisoning-induced brain injury

Olive leaves have an antioxidant capacity, and olive leaf extract can protect the blood, spleen and hippocampus in lead-poisoned mice. However, little is known about the effects of olive leaf extract on lead-induced brain injury. This study was designed to determine whether olive leaf extract can inhibit lead-induced brain injury, and whether this effect is associated with antioxidant capacity. First, we established a mouse model of lead poisoning by continuous intragastric administration of lead acetate for 30 days. Two hours after successful model establishment, lead-poisoned mice were given olive leaf extract at doses of 250, 500 or 1 000 mg/kg daily by intragastric administration for 50 days. Under the transmission electron microscope, olive leaf extract attenuated neuronal and capillary injury and reduced damage to organelles and the matrix around the capillaries in the frontal lobe of the cerebral cortex in the lead-poisoned mice. Olive leaf extract at a dose of 1 000 mg/kg had the greatest protective effect. Spectrophotometry showed that olive leaf extract significantly in- creased the activities of superoxide dismutase, catalase, alkaline phosphatase and acid phes- phatase, while it reduced malondialdehyde content, in a dose-dependent manner. Furthermore, immunohistochemical staining revealed that olive leaf extract dose-dependently decreased Bax protein expression in the cerebral cortex of lead-poisoned mice. Our findings indicate that olive leaf extract can inhibit lead-induced brain injury by increasing antioxidant capacity and reducing apop- tosis.

Autophagy Plays a Potential Role in the Process of Sea Cucumber Body Wall “Melting” Induced by UV Irradiation

The changes of tissue appearances and structures in the process of UV-induced ＂melting＂ for sea cucumber （Stichopus japonicus） body wall were studied. And the localization and determination of acid phosphatase （ACP）, Cathepsin B and Cathepsin L activities were also investigated. The results show that the connective tissue was damaged with many hollows emerging and the regular collagen bundles were broken apart into irregular fragments. Margination of condensed chromatin at the nuclear membrane was observed. Both Golgi＇s body and endoplasmic reticulure swelled, curled, and eventually double- or multi-lamellar vesicles were formed. A number of autophagic vesicles distributed in all through the whole cytoplasm. ACP becomes more active after UV irradiation. The activities of cathepsin B and cathepsin L increased in UV-treated sea cucumbers and both achieved their maximum under certain conditions, It indicates that autophagy plays a potential role in the ＂melting＂ process for sea cucumber body wall induced by UV irradiation.

Soluble protein and acid phosphatase exuded by ectomycorrhizal fungi and seedlings in response to excessive Cu and Cd

Fungi and their symbionts can alleviate heavy metal stress by exuding soluble proteins and enzymes. This study examined the role of soluble protein and acid phosphatase （APase） exuded by Xerocomus chrysenteron, an ectomycorrhizal fungus, and the seedlings of its symbiont, Chinese pine （Pinus tabulaeformis）, under conditions of excessive Cu and Cd. The growth type showed that this poorly studied ectomycorrhizal fungus was capable of tolerating high concentrations of Cu, and may be useful in phytoremediation. X. chrysenteron grew well at 80 mg/L Cu, and the EC50 for Cd was 17.82 mg/L. X. chrysenteron also showed enhanced exudation of soluble protein in both isolated and inoculated cultivations under the influence of Cu and Cd. Soluble protein exudation, however, differed under Cu and Cd stress in isolates. In mediums containing Cu, soluble protein exudation increased with concentration, but in mediums containing Cd the content of soluble protein increased to a comparable level at all concentrations. This study demonstrated that soluble protein was related to heavy metal tolerance, although the different ions played different roles. While APase activity in exudates of fungi and seedlings decreased under Cu and Cd stress in comparison to the control, the APase activity in seedlings was maintained by inoculation. Thus, X. chrysenteron facilitated the ability of plant to maintain a normal nutrient uptake, and therefore to protect it from heavy metal toxicity.

Effect of acid phosphatase produced by Trichoderma asperellum Q1 on growth of Arabidopsis under salt stress

Salt stress is a major environmental factor that inhibits crop growth.Trichoderma spp.are the most efficient biocontrol fungi and some of the strains can stimulate plant growth.Phosphate solubilization is known as one of the main mechanisms in promoting plant growth,but the underlying mechanisms of phosphate solubilization in the salinity still need to be explored.The Trichoderma asperellum Q1 isolated and identified in our lab is a beneficial rhizosphere biocontrol fungus with a high phosphate solubilization activity.It could produce acid and alkaline phosphatases when using insoluble organic phosphorus as the sole phosphorus source,the salt stress increased the phosphorus-solubilization ability of the strain and the activities of the two enzymes.Furthermore,an acid phosphatase was purified from the fermentation broth by ammonium sulphate precipitation,ion-exchange,and gel filtration chromatography.Its molecular weight was 55 k Da as determined by SDS-PAGE.The purified acid phosphatase was used to investigate growth performance of Arabidopsis thaliana by plate assay and the result showed that it contributed to Arabidopsis growth by transforming organic phosphate into a soluble inorganic form under salt stress.To our knowledge,this is the first report on acid phosphatase purification from T.asperellum and its function in regulation of plant growth under salt stress.

Effect of adrenalectomy and hydrocortisone on ventral prostate of rats

Aim: To study the effects of adrenalectomy and hydrocortisone on the ventral prostate of SD rats. Methods: Inadrenalectomised (ADX) and ADX + hydrocortisone (1, 2, or 4 mg) treated rats, the prostatic histology and thecholesterol, protein, zinc, and copper levels and the enzymic profile (acid phosphatase, alkaline phosphatase, aryl sul-phatase, lactic dehydrogenase, and leucine aminopeptidase) in the prostatic tissue were determined; the serum hormon-al profile (testosterone, FSH and LH) was also assayed. Results; Adrenalectomy caused a progressive degenerationin prostatic structure that was not reversed by hydrocortisone treatment. The serum testosterone were significantly lowerin ADX than in sham operated rats and lower in ADX + hydrocortisone than in ADX-C rats (P < 0.01). The serumFSH and LH were below the detection limit of 1 mIU/mL. The enzymatic activity was higher in ADX than in sham op-erated rats and higher in ADX + hydrocortisone than in ADX-C rats (P<0.05-0.01). The prostatic zinc levels weresignificantly higher in sham operated than in ADX, and higher in ADX-C than in ADX + hydrocortisone rats (P < 0.05-0.01). The prostatic copper level was significantly lower in sham operated than in ADX, and lower in ADX-C thanin the ADX + hydrocortisone rats (P <0.01). Conclusion; In rats, adrenalectomy leads to pathological and func-tional changes of the prostate. Hydrocortisone treatment at the doses employed did not reverse these changes. (Asian JAndrol 2001 Dec; 3: 289 - 300)

Utilizing zebrafish and okadaic acid to study Alzheimer's disease

Despite the many years of extensive research using rodent models to study Alzheimer＇s disease （AD）, no cure or disease halting drug exists. An increasing number of people are suffering from the disease and a therapeutic intervention is needed. Therefore, it is necessary to have complementary models to aid in the drug discovery. The zebrafish animal model is emerging as a valuable model for the investigation of AD and neurodegenerative drug discovery. The main genes involved in human AD have homologous counter- parts in zebrafish and have conserved function. The basic brain structure of the zebrafish is also conserved when compared to the mammalian brain. Recently an AD model was established by administering okadaic acid to zebrafish. It was used to test the efficacy of a novel drug, lanthionine ketimine-5-ethyl ester, and to elucidate its mechanism of action. This demonstrated the ability of the okadaic acid-induced AD zebrafish model to be implemented in the drug discovery process for therapeutics against AD.

Changes of Soil Enzyme Activities in Different Restoration Ages of Spruce Forests on the Eastern Qinghai-Tibet Plateau

Six soil enzymes (invertase, acid phosphatase, proteinase, catalase,peroxidase and polyphenoloxidase) were chosen for investigation under different spruce forests withrestoration ages of 4, 10, 16 years and an old-growth spruce forest over 400 yearsold in the easternQinghai-Tibet Plateau, China. Results showed that the activities of invertase, phosphatase,proteinase, catalase and peroxidase decreased in newly restored forests except forpholyphenoloxidase. With the development of forests after restoration, the activities of invertase,acid phosphadase, proteinase increased gradually. Our study also indicated that the soil enzymeactivities were associated with surface soils and decreased with depths. This result suggested thatin the earlier restoration stage the application of organic fertilizer may be more effective bysurface addition to soils than deep addition.

Effects of Lanthanum and Cerium on Acid Phosphatase Activities in Two Soils

To evaluate the security of using thulium, comparision between effects of La and those of Ce on acidic phosphatase activities in red soil and yellow soil in Zhejiang district was studied under conditions of ambient temperature and humidity. Results show that the acid phosphatase from different soil respondes to La and Ce differently. The activity of acid phosphatase in soil 1 declines with the increase of the concentration of La and Ce. The maximum inhibitory ratio of La and Ce reaches 69.8% and 71.0% respectively. But La and Ce have stimulative effect on the activity of acid phosphatase in soil 2. Under the effect of same concentration of the thulium, the acid phosphatase in two soils increases with the extending of culture time.

Adsorption of Acid Phosphatase on Minerals and Soil Colloids in Presence of Citrate and Phosphate

The aim of this work was to study the influence of phosphate and citrate, which are common inorganic and organic anions in soils, on the adsorption of acid phosphatase by kaolin, goethite and the colloids separated from yellow-brown soil (YBS) and latosol (LS) in central-south China. The YBS colloid has the major clay mineral composition of 1.4 nm mineral, illite and kaolinite while the LS colloid mainly contains kaolinite and oxides. The adsorption isotherm of acid phosphatase on the examined soil colloids and minerals fitted to the Langmuir model. The amount of enzyme adsorbed in the absence of ligands was in the order of YBS colloid > LS colloid > kaolin ≈ goethite. In the presence of phosphate or citrate, the amounts of the enzyme adsorbed followed the sequence YBS colloid > kaolin > LS colloid > goethite. The presence of ligands also decreased the binding energy between the enzyme and soil colloids or minerals. With the increase of ligand concentration from 10 mmol L-1 to 400 m mol L-1, different behaviors for the adsorption of enzyme were found in the colloid and mineral systems studied. A sharp decrease in enzyme adsorption was observed on goethite while gradual decreases of enzyme adsorption were recorded in the two soil colloid systems. However, no any decrease was found for the amount of enzyme adsorbed on kaolin at higher ligand concentrations. When phosphate or citrate was introduced to the system before the addition of enzyme, the ligands usually enhanced the adsorption of enzyme. The results obtained in this study suggested the important role of kaolinite mineral in the adsorption of enzyme molecules in acidic soils in the presence of various ligands.

Molecular Characterization and Functional Analysis of a New Acid Phosphatase Gene(Ha-acp1) from Heterodera avenae

For sedentary endo-parasitic nematodes, parasitism genes encoding secretory protein expressed in the subventral glands cells always play an important role during the early parasitic process. A new acid phosphatase gene （Ha-acp1） expressed in the subventral glands of the cereal cyst nematode （Heterodera avenae） was cloned and the characteristics of the gene were analyzed. Results showed that the gene had a putative signal peptide for secretion and in situ hybridization showed that the transcripts of Ha-acp1 accumulated speciifcally in the subventral gland cells of H. avenae. Southern blot analysis suggested that Ha-acp1 belonged to a multigene family. RT-PCR analysis indicated that this transcription was strong at the pre-parasitic juveniles. Knocking down Ha-acp1 using RNA interference technology could reduce nematode infectivity by 50%, and suppress the development of cyst. Results indicated that Ha-acp1 could play an important role in destroying the defense system of host plants.