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.

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.

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.

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.

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.

Detection of Ca^(2+)-dependent acid phosphatase activity identifies neuronal integrity in damaged rat central nervous system after application of bacterial melanin

The study aims to confirm the neuroregenerative effects of bacterial melanin （BM） on central nervous system injury using a special staining method based on the detection of Ca^2＋-dependent acid phosphatase activity. Twenty-four rats were randomly assigned to undergo either unilateral destruction of sensorimotor cortex （group I; n = 12） or unilateral rubrospinal tract transection at the cervical level （C3-4） （group II; n = 12）. In each group, six rats were randomly selected after surgery to undergo intramuscular injection of BM solution （BM subgroup） and the remaining six rats were intramuscularly in）ected with saline （saline subgroup）. Neurological testing confirmed that BM accelerated the recovery of motor function in rats from both BM and saline subgroups. Two months after surgery, Ca^2＋-dependent acid phosphatase activity detection in combination with Chilingarian＇s calcium adenoside triphosphate method revealed that BM stimulated the sprouting of fibers and dilated the capillaries in the brain and spinal cord. These results suggest that BM can promote the recovery of motor function of rats with central nervous system injury; and detection of Ca^2＋-dependent acid phosphatase activity is a fast and easy method used to study the regeneration-promoting effects of BM on the injured central nervous system.

Effects of Hg and Cu on the activities of soil acid phosphatase

Comparative study on the activity and kinectic properties of acid phosphatase （ACPase） of three soils amended with Hg and Cu at constant temperature and humidity was carried out. The results indicated that the inhibition on ACPase of the three sample soils by Hg and Cu varied with the content of soil organic matter and pH, where, Soil 1 was the most seriously contaminated due to its lowest content of organic matter and the lowest pH among three samples, Soil 2 took the second place, and Soil 3 was the least contaminated. Except Soil 3, the activity of soil ACPase tended to increase along with the contact time under the same type and the same concentration of heavy metal. In particular the Vmax values of ACPase in all three samples decreased with increasing Hg and Cu concentration, whereas the Km values were affected weakly. According to the change of Vmax and Km values, Cu and Hg had the same inhibition effect on soil ACPase. Both of them may he a type of compound of non-competitive and anti-competitive inhibition. Statistic analyses indicated that activities of soil ACPase and Vmax values could serve as bioindicator to partially denote the heavy metal Hg and Cu contamination degree.

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,

Effect of Salinity on Germination,Seedling Growth and Acid Phosphatase Activity in Lettuce

The impact of salt stress (NaCl 100 mM) on two lettuce varieties Romaine and Vista was conducted at germination and early seedling stages. The seeds of lettuce varieties were provided by the Seed Laboratory of Tunisian Ministry of Agriculture. The seeds were germinated in Petri dishes with double filter paper in distilled water (control) or NaCl solution (100 mM) for 5 days. The result showed that salinity significantly affected percentage and rate of germination in Vista variety but 100% of germination was found in Romaine. Length and fresh weight of root and shoot were reduced significantly with salt treatment in two lettuce varieties. Regarding biochemical analysis, acid phosphatase activity in root increased in Romaine and decreased in Vista. In shoot, this activity showed no difference with the control in the two varieties. However in cotyledons, and during 24 hours after germination, salinity decreased acid phosphatase activity in both varieties whereas in the later hours (48 - 96 h) this activity reached the value of the control in Romaine and Vista.

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.

Purple acid phosphatase promoted hydrolysis of organophosphate pesticides in microalgae

When organophosphate pesticides(OPs)are not used and handled in accordance with the current rules and standards,it results in serious threats to the aquatic environment and human health.Phaeodactylum tricornutum is a prospective microalgae-based system for pollutant removal and carbon sequestration.Genetically engineered P.tricornutum,designated as the OE line(endogenously expressing purple acid phosphatase 1[PAP1]),can utilize organic phosphorus for cellular metabolism.However,the competencies and mechanisms of the microalgae-based system(namely the OE line of P.tricornutum)for metabolizing OPs remain to be addressed.In this study,the OE line exhibited the effective biodegradation competencies of 72.12%and 68.2%for 30 mg L^(-1)of dichlorvos and 50 mg L^(-1)of glyphosate,accompanied by synergistic accumulations of biomass(0.91 and 0.95 g L^(-1))and lipids(32.71%and 32.08%),respectively.Furthermore,the biodiesel properties of the lipids from the OE line manifested a high potential as an alternative feedstock for microalgae-based biofuel production.A plausible mechanism of OPs biodegraded by overexpressed PAP1 is that sufficient inorganic P for adenosine triphosphate and concurrent carbon flux for the reduced form of nicotinamide adenine dinucleotide phosphate biosynthesis,which improved the OP tolerance and biodegradation competencies by regulating the antioxidant system,delaying programmed cell death and accumulating lipids via the upregulation of related genes.To sum up,this study demonstrates a potential strategy using a genetically engineered strain of P.tricornutum to remove high concentrations of OPs with the simultaneous production of biomass and biofuels,which might provide novel insights for microalgae-based pollutant biodegradation.

Colorimetric Detection of Acid Phosphatase and Malathion Using NiCo_(2)O_(4)Nanosheets as Peroxidase-Mimicking Activity

The establishment of a low-cost and facile approach for the assay of acid phosphatase(ACP)and its inhibitor is a research focus.In this paper,we successfully synthesized NiCo_(2)O_(4)nanosheets with peroxidase-mimicking activity in alkaline deep eutectic solvents(DESs)composed of NaOH and PEG-200,which can catalyze 3,3',5,5'-tetramethylbenzidine(TMB)to the oxidation state TMB(ox-TMB)in the presence of H2O2.Due to L-ascorbic acid-2-phosphate can be hydrolyzed into ascorbic acid by ACP,the peroxidase-like activity of NiCo_(2)O_(4)nanosheets is inhibited.However,the addition of malathion,an inhibitor of ACP,can inhibit the activity of ACP and thus limit the production of ascorbic acid(AA).Therefore,a colorimetric approach can be established for highly sensitive and selective detection of ACP and malathion with detection limits of 0.032 U/L and 0.65 nmol/L,respectively.More importantly,this method can be successfully applied to malathion detection in environmental samples tap water and food cucumber juice,indicating that it has potential application prospects in environmental and agricultural fields.

Overexpression of OsPAP10a, A Root-Associated Acid Phosphatase, Increased Extracellular Organic Phosphorus Utilization in Rice

Phosphorus （P） deficiency is a major limitation for plant growth and development. Among the wide set of responses to cope with low soil P, plants increase their level of intracellular and secreted acid phosphatases （APases）, which helps to catalyze inorganic phosphate （Pi） hydrolysis from organophosphates, in this study we characterized the rice （Oryza sativa） purple acid phosphatase 10a （OsPAPIOa）. OsPAPIOa belongs to group la of purple acid phosphatases （PAPs）, and clusters with the principal secreted PAPs in a variety of plant species including Arabidopsis. The transcript abundance of OsPAPIOa is specifically induced by Pi deficiency and is controlled by OsPHR2, the central transcription factor controlling Pi homeostasis. In gel activity assays of root and shoot protein extracts, it was revealed that OsPAPIOa is a major acid phosphatase isoform induced by Pi starvation. Constitutive overexpression of OsPAPIOa results in a significant increase of phosphatase activity in both shoot and root protein extracts. In vivo root 5-bromo.4-chloro-3-indolyl-phosphate （BCIP） assays and activity measurements on external media showed that OsPAPIOa is a root-associated APase. Furthermore, overexpression of OsPAPIOa significantly improved ATP hydrolysis and utilization compared with wild type plants. These results indicate that OsPAPIOa can potentially be used for crop breeding to improve the efficiency of P use.

Tartrate-resistant acid phosphatase 5b is a potential biomarker for rheumatoid arthritis： a pilot study in Han Chinese

Background Bone damage around the joints is one of the major pathophysiological mechanisms that leads to rheumatoid arthritis （RA） chronic disability.Serum tartrate-resistant acid phosphatase 5b （TRACP-5b） is secreted by osteoclasts,its activity can be used as a clinically relevant bone resorption marker.The aim of this study was to test whether the measurement of serum levels of TRACP-5b in patients with RA would correlate with measures of disease activity and with responses to therapy.Methods Fifty-six patients were randomly assigned to receive recombinant human cytotoxic tlymphocyte-associated antigen-4 immunoglobulin （RhCTLA4-lg）,infliximab or methotrexate （MTX）.The clinical and serologic indicators of RA activity were evaluated at baseline and at 24 weeks.Serum TRACP-5b was measured by Enzyme-linked Immunosorbent Assay （ELISA） at 0,12 and 24 weeks.Hand X-rays were obtained at baseline.Results At baseline,the levels of TRACP-5b correlated with the severity of X-ray damage,disease duration （r=0.332,P=0.012）,and tender joint count （r=0.408,P=0.002）.The 24 weeks values of TRACP-5b for RhCTLA4-lg group and infliximab group differed significantly from the baseline values in each group （P 〈0.05; P 〈0.05）,whereas only the value for RhCTLA4-lg group differed significantly from the 24 weeks value for the MTX group （P 〈0.01）.Considering the two biologics-treated groups together,the TRACP-5b levels at 24 weeks differed significantly from the baseline values only in those patients who reached an ACR70 level （P 〈0.05）.Conclusions Measurement of serum TRACP-5b in RA patients reflects clinical and radiological measures of disease activity,treatment with certain biologics,and degree of response to therapy.TRACP-5b should be investigated further as a potential biomarker to predict response to therapy,including slowing of radiographic progression.

Comparative genetic analysis of Arabidopsis purple acid phosphatases AtPAP10, AtPAP12, and AtPAP26 provides new insights into their roles in plant adaptation to phosphate deprivation

Induction and secretion of acid phosphatases （APases） is thought to be an adaptive mechanism that helps plants survive and grow under phosphate （Pi） deprivation, in Arabidopsis, there are 29 purple acid phosphatase （AtPAP） genes. To systematically investigate the roles of different AtPAPs, we first identified knockout or knock-down T-DNA lines for all 29 AtPAP genes. Using these atpap mutants combined with in-gel and quantitative APase enzyme assays, we demonstrated that AtPAP12 and AtPAP26 are two major intracellular and secreted APases in Arabidopsis while AtPAPlo is mainly a secreted APase. On Pi-deficient （P-） medium or P- medium supplemented with the organophosphates ADP and fructose-6-phosphate （Fru-6-P）, growth of atpaplo was significantly reduced whereas growth of atpap12 was only moderately reduced, and growth of atpap26 was nearly equal to that of the wild type （WT）. Overexpression of the AtPAP12 or AtPAP26 gene, however, caused plants to grow better on P- or P- medium supplemented with ADP or Fru-6-P. Interest-ingly, Pi levels are essentially the same for the WT and overexpressing lines, although these two types of plants have significantly different growth phenotypes. These results suggest that the APases may have other roles besides enhancing internal Pi recycling or releasing Pi from external organophosphates for plant uptake.

The discovery of the fat-regulating phosphatidic acid phosphatase gene

Phosphatidic acid phosphatase is a fat-regulating enzyme that plays a major role in controlling the balance of phosphatidic acid(substrate)and diacylglycerol(product),which are lipid precursors used for the synthesis of membrane phospholipids and triacylglycerol.Phosphatidic acid is also a signaling molecule that triggers phospholipid synthesis gene expression,membrane expansion,secretion,and endocytosis.While this important enzyme has been known for several decades,its gene was only identified recently from yeast.This discovery showed the importance of phosphatidic acid phosphatase in lipid metabolism in yeast as well as in higher eukaryotes including humans.

Effect of noise exposure(85 dB) on testicular adrenocortical steroidogenic key enzymes, acid and alkaline phosphatase activities of sex organs in mature albino rats

Changes in the activities of Δ 5\|3β\|hydroysteroid dehydrogenase(HSD) in testis and adrenal gland, 17β\|hydroxysteroid dehydrogenase in testis, acid and alkaline phosphatase in testis, prostate and seminal vesicle were observed in noise exposed mature rats at the intensity of 85 dB for 8 h/day for 45 days. The results indicated that noise exposed group showed a significant diminution in the activities of androgenic key enzymes Δ 5\|3β and 17β\|HSD, acid phosphatase in testis, prostate and seminal vesicle. There was a significant elevation in the activities of adrenal Δ 5\|3β\|HSD, alkaline phosphatase in testis and other accessory sex organ in noise exposed group. Gonadosomatic, prostatosomatic and seminal vesiculo\|somatic indexes were decreased significantly in noise exposed group. Therefore, it is evident that noise exposure at 85dB exerts a deleterious effect on testicular and adrenocortical activities.