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.

Effects of heat shock on change of HSC70/HSP68,acid and alkaline phosphatases before and after rat partial hepatectomy

INTRODUCTIONOnly the liver has the great capability ofregeneration in mammal.Few hepatocytes are inthe phase of division in the normal liver of an adultmammal (including human beings),but theremaining hepatocytes can be induced to proliferatequickly by partial hepatectomy (PH),and,to somedegree,they stop dividing and re-differentiate intocells functioning as hepatocytes.This shows

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.

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.

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.

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 mincral composition of 1.4 nm mincral,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 10mmol L^-1 to 400 m mol L^-1,different behaviors for the adsorption of cnzyme 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.

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 contami- nated 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 be 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.

Pachymic acid exerts antitumor activities by modulating the Wnt/β-catenin signaling pathway via targeting PTP1B

Objective:To determine the inhibitory effects of pachymic acid on lung adenocarcinoma(LUAD)cells and elucidate its underlying mechanism.Methods:CCK-8,wound healing,Transwell,Western blot,tube formation,and immunofluorescence assays were carried out to measure the effects of various concentrations of pachymic acid on LUAD cell proliferation,metastasis,angiogenesis as well as autophagy.Subsequently,molecular docking technology was used to detect the potential targeted binding association between pachymic acid and protein tyrosine phosphatase 1B(PTP1B).Moreover,PTP1B was overexpressed in A549 cells to detect the specific mechanisms of pachymic acid.Results:Pachymic acid suppressed LUAD cell viability,metastasis as well as angiogenesis while inducing cell autophagy.It also targeted PTP1B and lowered PTP1B expression.However,PTP1B overexpression reversed the effects of pachymic acid on metastasis,angiogenesis,and autophagy as well as the expression of Wnt3a andβ-catenin in LUAD cells.Conclusions:Pachymic acid inhibits metastasis and angiogenesis,and promotes autophagy in LUAD cells by modulating the Wnt/β-catenin signaling pathway via targeting PTP1B.

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.

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.

Assessment of a method for detecting serum HBV DNA with HBV DNA probe labelled directly by alkaline phosphatase

OBJECTIVE: To assess a sensitive and specific technique for detecting serum HBV DNA with an HBVDNA probe labelled directly by alkaline phosphatase (AlkPhos Direc probe).METHODS: AlkPhos Direc probe was prepared with purified HBV DNA labelled directly by alkalinephosphatase. The probe, and chemiluminescent substrate CDP-star for AP were used in hybridizationassay. HBV DNA was detected by autoradiography on a film. The results of 80 samples were comparedbetween the chemiluminescent dot blot hybridization assay with the AlkPhos Direc probe and another assaywith the digoxigenin-labelled HBV DNA probe. The correlation of seventy-sample results of fluorescentquantitative HBV DNA PCR assay and dot blot hybridization assay with the AlkPhos Direc probe wasanalysed.RESULTS: The sensitivity of the AlkPhos Direc probe was 10 pg at least. The coincidence of theAlkPhos Direc probe was 100% compared with that of the digoxigenin-labelled HBV DNA probe. Acorrelation coefficient of HBV DNA quantitative results between fluorescent quantitative HBV DNA PCRassay and dot blot hybridization assay with the AlkPhos Direc probe was 0.98 (P【0.01).CONCLUSIONS: The method detecting HBV DNA in serum with the HBV DNA AlkPhos Direc probe issensitive and specific. The results of the two assays with the AlkPhos Direc probe or with thedigoxigenin-labelled HBV DNA probe are completely coincident. The correlation of HBV DNAquantitative results between fluorescent QPCR assay and dot blot hybridization assay with the AlkPhosDirec probe is satisfactory.

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.

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.

非小细胞肺癌组织中lncRNA GAS5、LHPP表达与上皮间质化相关性及临床意义

目的探讨非小细胞肺癌(NSCLC)患者癌组织中长链非编码核糖核酸生长抑制特异性基因5(lncRNA GAS5)、磷酸赖氨酸磷酸组氨酸无机焦磷酸盐磷酸酶(LHPP)表达与上皮间质化(EMT)相关性及临床意义。方法收集2018年6月至2020年1月在河北北方学院附属第一医院行手术切除的NSCLC 90例患者的癌组织及癌旁组织,采用实时荧光定量聚合酶链反应检测lncRNA GAS5、LHPP和EMT相关蛋白[E-钙黏蛋白(E-Cad)、N-钙黏蛋白(N-Cad)和波形蛋白(VIM)]表达。分析NSCLC患者癌组织中lncRNA GAS5、LHPP mRNA与临床病理特征的关系,并通过Pearson相关性分析NSCLC患者癌组织中lncRNA GAS5、LHPP mRNA与EMT相关蛋白表达的相关性。采用Kaplan-Meier法绘制不同lncRNA GAS5、LHPP mRNA表达的NSCLC患者生存曲线,多因素Cox回归分析NSCLC患者预后的影响因素。结果NSCLC患者癌组织中lncRNA GAS5、LHPP mRNA、E-Cad mRNA表达低于癌旁组织,N-Cad mRNA、VIM mRNA表达高于癌旁组织,差异有统计学意义(P<0.05)。Pearson相关性分析显示,NSCLC患者癌组织中lncRNA GAS5与E-Cad mRNA表达呈正相关(r=0.724,P<0.001),与N-Cad mRNA、VIM mRNA表达呈负相关(r=-0.699、-0.689,P<0.001);lncRNA GAS5与LHPP mRNA表达呈正相关(r=0.651,P<0.001)。不同分化程度、肿瘤TNM分期、淋巴结转移的NSCLC患者癌组织中lncRNA GAS5、LHPP mRNA表达比较差异有统计学意义(P<0.05)。Kaplan-Meier生存曲线分析显示,lncRNA GAS5高表达组的3年总生存率[68.18%(30/44)]高于lncRNA GAS5低表达组的3年总生存率[36.96%(17/46)];LHPP mRNA高表达组的3年总生存率[67.39%(31/46)]高于LHPP mRNA低表达组的3年总生存率[36.36%(16/44)],差异有统计学意义(χ^(2)=10.274、10.322,P<0.05)。低分化、肿瘤TNM分期Ⅲ期、有淋巴结转移为NSCLC患者死亡的独立危险因素,lncRNA GAS5≥1.32、LHPP mRNA≥1.12为独立保护因素(P<0.05)。结论NSCLC患者癌组织中lncRNA GAS5、LHPP mRNA低表达,与EMT相关蛋白表达、分化程度、肿瘤TNM分期、淋巴结转移和预后有关,可能成为NSCLC诊治的新靶点。

新型酸性磷酸酶“Turn-on”型荧光底物

酸性磷酸酶(ACP)是前列腺癌、戈谢病、肾病等疾病的重要生物标记物,因此开发灵敏、高选择性的ACP检测方法具有重要的意义。目前,已发展出多种ACP检测方法,包括免疫法、光谱法、色谱法、电化学法等;其中,荧光检测方法因灵敏度高、选择性好、快速、准确等优点备受关注。通过席夫碱反应,利用2-氨基苯硼酸(2-APBA)二聚体和磷酸吡哆醛(PLP)合成了一种新型的ACP“Turn-on”型荧光底物APBA-PLP(ABPL)。反应后,PLP的—CHO基团和2-APBA二聚体的—NH 2基团的特征峰消失,同时ABPL的C N基团的特征峰出现;此外,^(1)H和^(1)H—^(1)H COSY核磁波谱的信号峰与ABPL的结构相对应。以上表征结果证实了ABPL的成功合成。进一步,将ABPL应用于ACP检测。我们发现向ABPL水溶液中加入ACP后,体系的荧光强度增强,机理为:2-APBA二聚体为聚集诱导发光增强(AIEE)分子,其AIEE特性源于2-APBA二聚体的高度有序堆积;当2-APBA二聚体分子上引入PLP后(即合成ABPL),分子的高度有序堆积结构被破坏;加入ACP后,PLP水解为吡哆醛并从2-APBA二聚体分子上脱落,2-APBA二聚体分子又可重新进行高度有序堆积,表现为体系的荧光增强。在0~5 U·L^(-1)活性范围内,376.5 nm处的相对荧光强度与ACP活性之间呈现出良好的线性关系(R 2=0.99)。此外,当ACP、果胶酶、木瓜蛋白酶和脂肪酶的活性分别为4、50000、80000和10000 U·L^(-1)时,四种酶对应的相对荧光强度分别为0.2、-0.006、0.03和0.05。该结果表明ABPL对ACP具有高选择性。ABPL分子易合成,对ACP具有线性和高选择性响应,为设计合成可用于ACP检测的新型高效荧光底物提供了新策略。

施磷增氧对水稻成熟期锌吸收分配及产量的影响

【目的】明确施磷、增氧及二者互作对水稻根系生理特性、成熟期锌吸收分配及产量的影响。【方法】以杂交稻C两优608作为盆栽试验对象,设置增氧(OI)、不增氧(NI)2种灌溉方式,4个施磷水平(P_(1)=0.00、P_(2)=1.35、P_(3)=2.70、P_(4)=4.05 g/盆),研究施磷、增氧对水稻各生育期根系活力、根系酸性磷酸酶活性和成熟期各部位含锌量及产量性状的影响。【结果】(1)施磷使铁锰胶膜含锌量降低33.38%~60.41%,增氧使锌由根部向秸秆转移系数增加24.98%~113.15%,氧磷互作促使水稻秸秆含锌量增加,降低了锌由秸秆向籽粒的转移系数及籽粒锌分配比例;(2)OIP_(1)处理水稻籽粒产量、千粒质量、有效穗数、籽粒锌分配比例均最高,分别为140.45 g/盆、27.57 g、29.00个/株、29.52%,是提高水稻籽粒产量及锌吸收的最佳灌溉模式;(3)施磷增加水稻分蘖期根系活力,降低灌浆期根系酸性磷酸酶活性,抑制成熟期根部锌的吸收和累积,促进锌由秸秆向籽粒转移,进而使籽粒产量及结实率增加;氧磷互作降低分蘖期根系酸性磷酸酶活性,增加灌浆期根系酸性磷酸酶活性,提高水稻秸秆、籽粒含锌量,降低了水稻有效穗数、结实率和水稻锌由秸秆向籽粒的转移能力。【结论】施磷、氧磷互作均可通过影响水稻分蘖期、灌浆期根系生理特性,调控水稻籽粒锌吸收及锌由秸秆向籽粒的转移系数以影响水稻产量形成;增氧则促进水稻秸秆锌的吸收与分配。