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.

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.

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.

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.

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,

Identification of an Mg2+-Independent Soluble Phosphatidate Phosphatase in Cottonseed (Gossypium hirsutum L.)

Cotton (Gossypium hirsutum L.) provides a major source of oil for food and feed industries, but little was known about the enzymes in the oil biosynthesis pathway in cottonseed. We are interested in a better understanding of enzymatic components for oil accumulation in cottonseed. The objective of this study was to identify one key enzyme in oil biosynthesis pathway: phosphatidic acid phosphatase (PAP, 3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4). PAP hydrolyzes the phosphomonoester bond in phosphatidate yielding diacylglycerol and Pi. PAPs are generally categorized into Mg2+-dependent soluble PAP and Mg2+-independent membrane-associated PAP. Cottonseed from 25 - 30 days post anthesis was used for the study. The results showed that an Mg2+-independent soluble PAP activity was identified from the cottonseed. While the microsomal fraction of the extract provided only 9% of the PAP activity, 69% of the PAP activity was associated with the cytosol. The PAP activity correlated well with enzyme concentration and incubation time. The pH and temperature optima of the enzyme were pH 5 and 55℃, respectively. Under optimized assay conditions, the Vmax and Km values of cottonseed PAP for dioleoyl phosphatidic acid as the substrate were 2.8 nkat/mg of protein and 539 μM, respectively. Inclusion of the detergent Triton X-100 (0% - 0.5%) or magnesium chloride (1 mM) in the reaction mix did not alter activity to a significant degree. This is the first report of a PAP activity in the seeds of Gossipium hirsutum. This study should provide a basis for purification and characterization of this important enzyme from cottonseed in the future.

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.

Phosphorus Starvation Tolerance in Rice Through Combined Physiological,Biochemical,and Proteome Analyses

Phosphorus(P) deficiency limits the growth,development,and productivity of rice.To better understand the underlying mechanisms in P-deficiency tolerance and the role of Pup1 QTL in enhancing P use efficiency(PUE) for the development of P-efficient rice cultivars,a pair of contrasting rice genotypes(Pusa-44 and NIL-23) was applied to investigate the morpho-physio-biochemical and proteomic variation under P-starvation stress.The rice genotypes were grown hydroponically in a PusaRich medium with adequate P(16 mg/kg,+P) or without P(0 mg/kg,-P) for 30 d.P-starvation manifested a significant reductions in root and shoot biomass,shoot length,leaf area,total chlorophyll,and P,nitrogen and starch contents,as well as protein kinase activity.The stress increased root-to-shoot biomass ratio,root length,sucrose content,and acid phosphatase activity,particularly in the P-tolerant genotype(NIL-23).Comparative proteome analysis revealed several P metabolism-associated proteins(including OsCDPKs,OsMAPKs,OsCPKs,OsLecRK2,and OsSAPks) to be expressed in the shoot of NIL-23,indicating that multiple protein kinases were involved in P-starvation/deficiency tolerance.Moreover,the up-regulated expression of OsrbcL,OsABCG32,OsSUS5,OsPoll-like B,and ClpC2 proteins in the shoot,and OsACA9,OsACA8,OsSPS2F,OsPP2C15,and OsBiP3 in the root of NIL-23,indicated their role in P-starvation stress control through the Pup1 QTL. Thus,our findings indicated that-P stress-responsive proteins,in conjunction with morpho-physio-biochemical modulations,improved PUE and made NIL-23 a P-deficiency tolerant genotype due to the introgression of the Pup1 QTL in the Pusa-44 background.

Effect of Purified Paper Wasp Ropalidia marginata Venom Toxin Enzyme Activity in Blood Serum, Liver, and Gastrocnemius Muscle of Albino Mice

In the present, investigation effects of sub-lethal dose of purified paper wasp Ropalidia marginata venom toxins were evaluated on important metabolic enzymes i.e. ALP ACP, GPT, GOT, LDH, and AchE enzyme activity in serum, liver, and gastrocnemius muscles of albino mice. Alkaline phosphatase was found to be increased up to 119.9% at the 6th hr of the toxin injection in comparison to control. This elevation may be due to cytolysis. Maximum increase i.e., 153.33% level of glutamate pyruvate transaminase (GPT) was found at 6 hrs of 40% of 24-h LD50 treatment while it was found to be 151.1% at 6 hrs of 24 hr 80% of LD50, venom injection. A significant elevation was observed in LDH activity in serum, liver, and muscles, while the activity of AchE was decreased in serum, liver, and gastrocnemius muscles of albino mice after injecting the sub-lethal dose of Ropalidia marginata venom. This increase in the activity of LDH produces liver damage, massive disintegration and necrosis of hepatic cells. This elevation in LDH level led to a significant increase in the glucose catabolism and elevated oxidative stress in muscle and liver cells. It also displays insufficient oxygen supply and consequently leads to cell death. In experimental animals, venom toxin treatment decreased AchE level, and animals showed muscular paralysis. When mice were treated with 40% and 80% of 24-h LD50 of purified venom caused a significant (p < 0.05) elevation in the level of ACP, GOT, GPT, and LDH while the reduction in ALP and AChE level. Present study will be useful in the development of prototypes for study of pharmacological and therapeutic effects of various venom toxins. For this purpose structure activity relationship of enzyme and venom toxin, its due interaction to various metabolic enzymes and receptors must be explored.

Effects of Purified Indian Cattle Tick Rhipicephalus microplus Saliva Toxins on Various Enzymes in Blood Serum, Liver and Muscles of Albino Mice

In the present investigation, in vivo effects of purified ticks’ saliva toxin were evaluated on the level of certain important cellular metabolic enzymes i.e. acid phosphatase (ACP), alkaline phosphatase (ALP), glutamate pyruvate transaminase, glutamate oxaloacetate transaminase and lactic dehydrogenase. For this purpose, sub-lethal doses, 40% and 80% of 24 h LD50 purified saliva toxins of Rhipicephalus microplus (Canestrini, 1888) were injected subcutaneously in the albino mice. In treated mice saliva toxins targeted membrane-bound enzymes i.e. serum acid phosphatase and alkaline phosphatase, its level was increased from 118.30% to 163.63% at the 6th hr in comparison to the control. Besides this, the levels of serum glutamate pyruvate transaminase (GPT) and glutamate oxaloacetate transaminase (GOT) and lactic dehydrogenase (LDH) also increased up to 161.11% (at 6th hr), 148.27 (at 8th hr) and 125.45% (at 6th hr) respectively in comparison to control. An increase in the level of LDH showed insufficient oxygen supply, massive disintegration of cells and leakage of the enzyme into the circulation. It clearly indicated the toxic effects of saliva toxins on the membrane of blood cells, hepatocytes and myocardial muscle cell functions in albino mice. On the other hand activity of acetyl cholinesterase was reduced by 65.51% at the 6th hr of the saliva toxin injection in comparison to the control. This inhibition of acetyl cholinesterase activity caused the accumulation of acetylcholine molecules at the synaptic junctions and led to prolonged activation of acetylcholine receptors. It caused permanent stimulation of nerves and muscle cells that may result in muscular paralysis and finally death of the animal.

Acid-Phosphorus Activity of Wheat Varieties Rhizobacteria of Uzbekistan

In this work, local strains of phosphate-solubilizing microorganisms were isolated and identified from the wheat rhizosphere and exogenous acid phosphatase enzymes of locally active phosphate- and potassium-mobilizing rhizobacteria belonging to the genera Escherichia, Rahnella, Bacillus, Enterobacter, Pseudomonas, and Pantoea were studied. The efficiency of the physiological properties of rhizobacteria is determined by the production of soluble phosphorus, and the amount of phosphorus depends on the activity and biomass of bacteria that secrete phosphorus. This is done by phosphate solubilizing bacteria, and the habitat ecosystem is enriched with beneficial micronutrients. In these studies, active rhizobacteria activity of acid phosphatase in nutrient liquid was studied at different temperatures. Optimum pH activity index and temperature variability of enzymes were determined. It should be noted that in the most active phosphate-solubilizing strains the maximum enzymatic activity was observed in the culture fluid of R. aquatilis strain 17, which produced 1.086 μmol p-nitrophenol μmol/min/ml. P. agglomerans 22, P. agglomerans 20 and Ps. kilonensis 32 cultures phosphatase activity was 0.143 - 0.680 p-nitrophenol μmol/min/ml. It should be noted that the phosphatase activity of bacteria belonging to the same genus and species was very different from each other. That is, the enzyme activity of Rahnella aquatilis strain 17 was 9 times higher than the enzyme activity of Rahnella aquatilis strain 9. The pH optimum of sour phosphatase enzymes in Rahnella aquatilis strain 16 was 6.0. The optimum temperature of acid phosphatase activity was 45˚C and 50˚C. The reason for this may be that the strains were isolated in different soil and climate conditions. When the acid phosphatase activity of R. aquatilis 3, 9, E. cloacae 8 and P. agglomerans 22 cultures was determined at a temperature of 45˚C, it was observed that the enzyme activity increased by 2 - 4 times. Es. hermannii 1, Ps. kilonensis 26 and B. simplex 28 bacteria acid phosphatase activity was not significantly affected by temperature rise.

Global patterns of soil phosphatase responses to nitrogen and phosphorus fertilization

Hydrolysis of organic phosphorus(P) by soil phosphatases is an important process of P cycling in terrestrial ecosystems, significantly affected by nitrogen(N) and/or P fertilization. However, how soil acid phosphatase(ACP) and alkaline phosphatase(ALP) activities respond to N and/or P fertilization and how these responses vary with climatic regions, ecosystem types, and fertilization management remain unclear. This knowledge gap hinders our ability to assess P cycling and availability from a global perspective. We performed a meta-analysis to evaluate the global patterns of soil ACP and ALP activities in response to N and/or P addition. We also examined how climatic regions(arctic to tropical), ecosystem types(cropland, grassland, and forest), and fertilization management(experiment duration and fertilizer type and application rate) affected changes in soil phosphatases after fertilization. It was shown that N fertilizer resulted in 10.1% ± 2.9% increase in soil ACP activity but a minimal effect on soil ALP activity. In contrast, P fertilizer resulted in 7.7% ± 2.6% decrease in soil ACP activity but a small increase in soil ALP activity. The responses of soil ACP and ALP activities to N and/or P fertilization were largely consistent across climatic regions but varied with ecosystem types and fertilization management, and the effects of ecosystem types and fertilization management were enzyme-dependent. Random forest analysis identified climate(mean annual precipitation and temperature) and change in soil pH as the key factors explaining variations in soil ACP and ALP activities. Therefore, N input and ecosystem types should be explicitly disentangled when assessing terrestrial P cycling.