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1.
The relationship between acid phosphatase activity (APA) and phosphorus (P) stress in two bean genotypes (Phaseolus vulgaris var Tacarigua and var Manuare) and in cowpea (Vigna unguiculata var TUY) are reported in this paper. Sand culture experiments were performed in a highly ventilated greenhouse where plants were drip feed with nutrient solutions with either 1.0 or 0.02 mM P. Acid phosphatase activity was determined in extracts from roots, young (apical) and mature leaves, and in leaf discs and root sections using o‐carboxyphenyl phosphate as substrate. Differences in total dry matter were found to be significant (P = 0.01) only for cowpea. However, reduction in leaf area was significant in both species and varieties. Differences in the P concentration in the dry matter, were large enough to suspect that plants were suffering from a mild P stress. Acid phosphatase activity was above the values reported for these species under P stress, however, APA in these legumes appears not to be inducible by the low P‐concentration level used in this study. A higher APA was found in young as compared to mature leaves, and the expression of APA also showed intraspecific variation. Acid phosphatase activity was related to the age of the leaves and was easily measured in leaf discs, specially for bean. This and the ratio of P concentration between young and mature leaves may be an alternative to absolute P‐status determination in plants. 相似文献
2.
The effects of nitrogen (N‐) and phosphorus (P‐) deficiency, isolatedly or in combination, on growth, nitrogenous fraction, and inorganic phosphate in xylem exudade, and photosynthesis of common bean (Phaseolus vulgaris L. cv. Negrito) were investigated. Plants were grown in nutrient solution adjusted daily to pH 5.5 and aerated continuously. Ten days after emergence mineral deficiency was imposed. Plants were then supplied with high N (7.5 mol m‐3) or low N (0.5 mol m‐3), and also with high P (0.5 mol m‐3) or low P (0.005 mol m‐3). All sampling and measurements were made 28 days after emergence. N‐ or P‐deprivation brought about large decreases in total leaf area by inhibiting the emergence of new leaves and primarily the expansion of the leaves. The specific leaf area did not change under N‐ but decreased under P‐limitation. The decreased shoot to root ratio in all deficiency treatments was a consequence of a lowering mass of above‐ground organs, especially of leaves. The content of chlorophylls declined significantly only under N‐deficiency alone; carotenoids declined under both N‐ and combined N‐ and P‐limitation. No alteration in amino acid concentration in xylem exudate occurred in plants experiencing N‐starvation, while ureides increased by 79%, and nitrate and inorganic phosphate decreased greatly. Under P‐deprivation, amino acids and nitrate in xylem sap dropped by about half; ureides were held relatively constant, and phosphate was severely depressed. Total upward translocation of N through xylem was estimated to be about 16% higher in N‐deficient plants than in plants without mineral limitation, but leaf N levels in the former were lower as compared to control plants. The net carbon (C) assimilation decreased similarly regardless of the imposed deficiency treatment. Such a decrease was mainly determined by non‐stomatal factors. In general, no additive effect between N‐ and P‐limitation on any of measured parameters was observed. 相似文献
3.
聚氨酯包膜和喷涂诱抗剂提高滨海盐化潮土玉米产量和磷肥利用率的协同效应 总被引:1,自引:0,他引:1
4.
磷是植物生长和发育中最重要的必须元素之一。尽管土壤中磷资源很丰富,但大部分磷是以植物不能吸收利用的固定态和有机态存在,特别是以酸性土壤为主的南方稻田,水稻缺磷现象非常严重。理解和掌握水稻对低磷的适应机制有助于利用分子手段培育磷高效利用水稻品种。为阐明蔗糖提高水稻耐低磷的机制,本研究对水稻幼苗进行不同磷、糖处理,分析水稻幼苗在不同磷糖配比培养基中的根系结构、无机磷、酸性磷酸酶活性的变化,并利用定量RT-PCR技术分析水稻磷酸转运蛋白基因(OsPT)和酸性磷酸酶基因(OsSAP1)的表达。试验设2个磷浓度:无磷和85 mg·L?1KH2PO4,2个蔗糖浓度:无糖和3%蔗糖,正交设计。结果表明,在低磷胁迫时添加蔗糖,能使水稻幼苗的根总长度、总根数、根冠比显著增加,根分泌的酸性磷酸酶活性降低,但水稻体内的磷酸转运酶活性提高。11个与磷具有高度亲和力的磷酸转运酶的表达发生了改变,其中根优势表达的4个基因OsPT2、OsPT3、OsPT4、OsPT6对磷、糖的影响最为敏感,暗示了蔗糖是通过调节磷转运蛋白维持磷的吸收和平衡。增加根系的蔗糖分配能够提高水稻幼苗对磷胁迫的耐受性。 相似文献
5.
《Communications in Soil Science and Plant Analysis》2012,43(19-20):3239-3248
Abstract Tomato cultivars Blizzard and Liberto were grown hydroponically in a controlled temperature (C.T.) room for 35 days. The objective was to investigate the relationship between phosphorus (P) concentration and acid phosphatase enzyme [EC.3.1.3.2.] (APE) activity in leaves in relation to zinc (Zn) concentration in nutrient solution. Zinc was added at concentrations of 0.01,0.5, and 5 mg L‐1. The 0.01 and 5 mg L‐1 Zn treatments led to a significant reduction in dry matter and total chlorophyll content compared with 0.5 mg L‐1 for both cultivars. Zinc concentration was considered inadequate in the leaves of plants subjected to 0.01 mg L‐1 Zn, while it was at toxic level in those in the 5 mg L‐1 Zn treatment according to values stated for tomato plants. Optimal results for all criteria tested in this experiment were for plants grown in 0.5 mg L‐1 Zn treatment. In the leaves of plants grown at 0.01 mg L‐1 Zn, APE concentrations were significantly the lowest and concentrations of P were at a toxic level. The APE activity was noticeably higher in the P‐deficient plants of both cultivars grown in the solutions with high Zn (5 mg L‐1). 相似文献
6.
The influence of phosphorus nutrition and pH on phosphatase activity of sugar beet roots For the determination of acid phosphatase activity (Pase) of sugar beet roots (cultivar: Reka), plants were cultivated in nutrient solution with 1 or 100 μM P in a growth chamber for 12, 18, 24, 30, 36 and 42 days. The phosphatase activity of intact roots was measured in buffer solutions with pH 4 to 7.2 and 14 mM p-Nitrophenylphosphate (NPP) after 10 min of incubation at 20°C. The influence of P nutrition on Pase activity was significant at all intervals. At P deficiency the activity was increased by a factor of 4 to 20. During the experimental period the pH optimum was 6. At pH 5 and 7.2 the Pase activity reached only 63 and 64% respectively of the optimum value. At P deficiency (1 μmol P L—1) the absolute rate of NPP-hydrolysis at pH 6 was 144 nmol min1 m1 root length (day 12 to 36). The plants which received optimum P supply showed only 10% of this value. Sugar beet roots with P deficiency have a high potential of Pase activity from the acid to the neutral pH-range. Therefore, under this condition they may effectively use dissolved organic phosphorus compounds. 相似文献
7.
《Journal of plant nutrition》2013,36(10):2205-2228
ABSTRACT Chlorosis in crops grown on calcareous soil is mainly due to iron (Fe) deficiency and can be alleviated by leaf application of soluble Fe2+ or diluted acids. Whether chlorosis in indigenous plants forced to grow on a calcareous soil is also caused by Fe deficiency has, however, not been demonstrated. Veronica officinalis, a widespread calcifuge plant in Central and Northern Europe, was cultivated in two experiments on acid and calcareous soils. As phosphorus (P) deficiency is one of the major causes of the inability of many calcifuges to grow on calcareous soil we added phosphate to half of the soils. Leaves in pots with the unfertilized and the P-fertilized soil, respectively, were either sprayed with FeSO4 solution or left unsprayed. Total Fe, P, and manganese (Mn) in leaves and roots and N remaining in the soil after the experiment were determined. In a second experiment, no P was added. Leaves were either sprayed with FeSO4 or with H2SO4 of the same pH as the FeSO4 solution. Degree of chlorosis and Fe content in leaves were determined. Calcareous soil grown plants suffered from chlorosis, which was even more pronounced in the soils supplied with P. Newly produced leaves were green with Fe spray but leaves that were chlorotic before the onset of spraying did not totally recover. H2SO4 spray even increased chlorosis. This demonstrated that chlorosis was due to Fe deficiency. As total leaf Fe was similar on acid and calcareous soil, it was a physiological Fe deficiency, caused by leaf tissue immobilization in a form that was not metabolically “active”. Iron in the leaves was also extracted by 1,10-phenanthroline, an Fe chelator. In both experiments, significant differences between leaves from acid and calcareous soil were found in 1,10-phenanthroline extractable Fe but not in total leaf Fe, when calculated on a dry weight basis. Differences in 1,10-phenanthroline extractable Fe were more pronounced when calculated per unit dry weight than calculated per leaf area, whereas the opposite condition was valid for total leaf Fe. 相似文献
8.
Previous studies describe the suitability of a new type of phosphorus (P) fertilizer, called “rhizosphere‐controlled fertilizer” (RCF), to supply available P to plants while reducing soil phosphorus fixation. In order to explore the involvement of organic acid root exudation in P uptake from RCF, we investigated the relationship between shoot and root P concentrations, and the concentration of the main polycarboxylic organic acids in roots, shoots, and plant exudates. Plant species with different P‐acquisition efficiency (low: maize; medium: chickpea; high: lupin) were grown in hydroponics with three different P fertilizers: The water‐insoluble P fraction of RCF (RCF); Phospal, a slow‐release source of phosphate composed of calcium and aluminum phosphates (PH); monopotassiumphosphate (KP), and a control treatment without P (P–). RCF was as efficient as KP in supplying P to plants in the case of chickpea and lupin, and slightly less efficient than KP in maize. However, P from PH was not available for maize and less available compared to KP and RCF in chickpea and lupin. This variation reflects the different efficiencies in P acquisition for the three plant species. Except in the case of maize, plants receiving KP presented the lowest concentration of organic acids in roots and exudates, while those plants suffering severe P deficiency (P– and PH) showed the highest organic acid concentration. However, RCF had a high concentration of organic acids in roots and exudates, as well as a high P concentration in the shoot indicating that P uptake from RCF is enhanced due to root release and action of specific organic acids. 相似文献
9.
10.
Impact of Boron Deficiency on Changes in Biochemical Attributes,Yield, and Seed Reserves in Chickpea
《Communications in Soil Science and Plant Analysis》2012,43(2):199-206
To determine the effect of boron (B) deficiency on biomass, reproductive yield, metabolism, and alterations in seed reserves of chickpea (Cicer arietinum L.) cv. ‘13.G‐256,’ plants were grown in refined sand until maturity at deficient (0.033 mg L?1) and adequate (0.33 mg L?1) B, supplied as boric acid (H3BO3). Boron‐deficient plants exhibited visible deficiency symptoms in addition to reduced number of pods and seeds, resulting in lowered biomass and economic yield. Boron deficiency lowered the concentration of B in leaves and seeds, photosynthetic pigments (leaves), Hill reaction activity, starch (in leaves and seeds), and proteins and protein N (in seeds), whereas phenols, sugars (in leaves and seeds), and nonprotein N (in seeds) were elevated. Specific activity of peroxidase (POX) increased in leaves and pod wall and decreased in seeds, while activity of acid phosphate and ribonuclease were stimulated in leaves, seeds, and pod wall in B‐deficient chickpea. 相似文献
11.
David Wm. Reed 《Journal of plant nutrition》2013,36(8):667-677
Various glues and adhesives were tested for their ability to remove the unabsorbed residue from drops of foliar applied radioactive nutrients to Ficus benjamina L. and Glycine max Merr. Most glues/adhesives adequately removed the unabsorbed residue from nutrients that dried forming a salt deposit on the leaf surface, but only 1.6–3.2% agar, Rhoplex 33, and Elmers Glue removed greater than 95% of the residue from nutrients that formed a moist hygroscopic residue on the leaf surface. Adding 25 mM KH2PO4 to 3.2% agar, followed by swabbing the treated area with lN HCl‐1% Liquinox detergent removed all unabsorbed residue from monovalent and divalent cationic an anionic nutrients including heavy metals. Methods to assay foliar absorption were compared by applying “Rb phosphate to leaves of intact plants, excised leaves and leaf discs. Excised leaves with their petiole or stem bases in water behaved similar to intact plants, whereas excised leaves or discs maintained in in a moist atmosphere behaved atypically due to slower and incomplete drying compared to intact plants. 相似文献
12.
A. Mozafar 《Journal of plant nutrition》2013,36(7-8):999-1005
Distribution often elements along the maize leaf and the effect of iron (Fe) deficiency on these distributions were studied using plants grown in nutrient solution. In both the control and Fe‐deficient leaves, the concentrations of Fe, calcium (Ca), magnesium (Mg), manganese (Mn), zinc (Zn), and boron (B) increased and only that of potassium (K) decreased from leaf base to the leaf tip. Nitrogen (N) and copper (Cu) were the only two elements which showed no gradient of concentration along the entire leaf. Iron deficiency decreased the concentration of Fe by the same extent along the entire leaf length. However, it differentially accentuated the uneven distribution of some elements along the leaf length. For example, Fe deficiency increased the concentrations of Cu and N somewhat uniformly along the whole length the leaf; those of P and K were increased only along the lower two‐thirds of the leaves; and those of Ca, Mg, B, Zn, and Mn mostly along the upper one‐half to one‐third of the leaf length. Potassium was the only element whose concentration was lower at leaf tip than at the leaf base under both Fe‐sufficient and Fe‐deficient conditions. My results indicate that the basal half of maize leaf may be a more suitable part for diagnostic purposes since the concentration of most elements is less subject to alteration in this region, especially if a latent or obvious Fe deficiency is present. In view of these observations, the use of the entire maize leaf for diagnostic purposes may have to be reevaluated. 相似文献
13.
J. A. Passarinho M. L. Rodrigues M. L. Osório C. P. P. Ricardo M. M. Chaves 《Journal of plant nutrition》2013,36(4):487-505
The response to phosphorus (P) concentration in the nutrient solution (0–0.5 mol P m‐3) was studied in Lupinus mutabilis Sweet cv. Potosi in two different seasons (winter and spring). Phosphorus deficiency was more severe on growth than on photosynthesis and the season of growth dramatically influenced the optimal concentration of P for plant growth; root biomass was proportionally less affected than shoot biomass. During winter, growth and photosynthesis of plants supplied with 0.02–0.5 mol P m‐3 were not significantly different, whereas in spring, rates of growth and photosynthesis were faster at the 0.5 mol P m‐3 level. Stomatal conductance decreased with deficient P independently of leaf water relations. Severe P deficiency limited carbon (C) assimilation rates due to reduction in stomatal conductance and mesophyll photosynthetic capacity. Decreased sucrose/starch in P‐deficient leaves was a consequence of the observed source/sink imbalance which was more marked in winter. Hydraulic conductance was not a limiting factor for leaf expansion under low P. In conclusion, growth and metabolic changes observed in lupins grown at low P supply can be ascribed to an adjustment at the whole plant level, preventing a large drop in leaf P, reducing shoot growth and facilitating P uptake through higher root biomass. 相似文献
14.
Depletion of organic phosphorus from Oxisols in relation to phosphatase activities in the rhizosphere 总被引:2,自引:0,他引:2
T. S. George B. L. Turner P. J. Gregory B. J. Cade-Menun & A. E. Richardson 《European Journal of Soil Science》2006,57(1):47-57
Phosphorus (P) deficiency is a major limitation to agricultural production in many parts of the world. It is therefore desirable to identify plants with enhanced abilities to utilize P more efficiently. Exudation of phosphatase from roots may improve P availability, yet there is little direct evidence for this. Here we report the dynamics of organic P in the rhizosphere of plants that have enhanced rhizosphere phosphatase activity. Agroforestry species and transgenic subterranean clover (engineered to produce phytase) were compared with crop and wild‐type plant controls, respectively. Depletion of organic P was measured in pools defined by chemical extraction, solution 31P NMR spectroscopy, and microbial immobilization of radio‐isotopic P. Plants that had greater extracellular phosphatase activity depleted more organic P from P‐deficient Oxisols than control plants. Depleted organic P forms were primarily phosphate monoesters. Plants with enhanced extracellular phosphatase activity also had access to a pool of soil P that was less isotopically exchangeable. Transgenic subterranean clover that expresses a microbial phytase gene appeared to have greater access to recently immobilized P, whereas plants expressing endogenous phosphatases utilized the unlabelled portion of soil organic P to a greater extent. Collectively, these results indicate that the enhancement of phosphatase activity in the rhizosphere of plants is implicated in the depletion of organic P forms from soils, most notably orthophosphate monoesters, whilst also suggesting that there is some exclusivity to the pools of organic P utilized by plants and microorganisms. 相似文献
15.
16.
The effect of Zn deficiency on rate of photosynthesis of leaf discs, isolated mesophyll and bundle sheath cells and chloroplasts of maize (Zea mays. L) was studied. The yield of mesophyll and bundle sheath cells obtained by enzymic digestion of the leaf tissues from Zn deficient plants is lower than the identical tissues from normal plants which suggests that Zn deficiency brings about some structural changes in the leaf cell. Photosynthetic oxygen evolution measured in the leaf discs is low due to Zn deficiency. Photosystem‐II dependent Hill reaction and non cyclic photophosphorylation of chloroplasts were also affected by Zn deficiency. Rate of photosynthetic carbon dioxide fixation by both bundle sheath and mesophyll cells obtained from Zn deficient leaf‐tissue waslower than the cells free from Zn deficiency. Addition of various metabolites like NADPH, ATP and PEP to Zn deficient mesophyll cells whowed marked enhancement in 14‐CO2 fixation. However, addition of NADPH, ATP and RuBP to Zn deficient bundle sheath cells showed no or very little enhancement in the rate of 14‐Cu2 fixation. Addition of exogenous Zn ions to isolated cells inhibited the CO2 fixation both in the non‐deficient and Zn deficient cell types. It is suggested that Zn deficie ‐ncy affects the primary electron transport and phospho‐rvlation ability for chloroplasts which in turn affects CO2 fixation in leaf cells. 相似文献
17.
18.
《Communications in Soil Science and Plant Analysis》2012,43(19-20):2812-2826
Co‐application of biosolids and water treatment residuals (WTR) land has not been extensively studied but may be beneficial by sorbing excess biosolid‐borne or soil phosphorus (P) onto WTR, reducing the likelihood of off‐site movement. Reduction of excess soil P may affect the role of specific P‐cleaving enzymes. The research objective was to understand the long‐term effects of single co‐applications and the short‐term impacts of repeated co‐applications on soil acid phosphomonoesterase, phosphodiesterase, pyrophosphatase, and phytase enzyme activities. Test plots were 7.5 × 15 m with treatments consisting of three different WTR rates with a single biosolids rate (5, 10, and 21 Mg WTR ha?1; 10 Mg biosolids ha?1) surface co‐applied once in 1991 or reapplied in 2002. Control plots consisted of those that received no WTR–biosolids co‐applications and plots that received only 10 Mg biosolids ha?1. Plots were sampled to a 5‐cm depth in 2003 and 2004, and soil phosphatases and phytase enzyme activities were measured. Soil phosphodiesterase activity decreased in WTR‐amended plots, and pyrophosphatase activity decreased with increasing WTR application rates. In contrast, acid phosphatase and phytase activity increased with WTR addition, with WTR application possibly triggering a deficiency response causing microorganisms or plants to secrete these enzymes. Biosolids and WTR co‐applications may affect enzymatic strategies for P mineralization in this study site. Reductions in phosphodiesterase activity suggest less P mineralization from biomass sources, including nucleic acids and phospholipids. Increased acid phosphatase and phytase activities indicate that ester‐P and inositol‐P may be important plant‐available P sources in soils amended with WTR. 相似文献
19.
The impact of phosphorus (P) deficiency on response of symbiotic N2 fixation and carbohydrate accumulation in soybean (Glycine max [L.] Merr.) to atmospheric CO2 enrichment was examined. Plants inoculated with Bradyrhizobium japonicum MN 110 were grown in growth chambers with controlled atmospheres of 400 and 800 μL CO2 L‐1 and supplied either 1.0 mM‐P (P‐sufficient) or 0.05 mM‐P (P‐deficient) nitrogen (N)‐free nutrient solution. When plants were supplied with sufficient P, CO2 enrichment significantly increased whole plant dry mass (83%), nodule mass (67%), total nitrogenase activity (58%), and N (35%) and P (47%) accumulation at 35 days after transplanting (DAT). Under sufficient P supply, CO2 enrichment significantly increased starch concentrations in nodules compared to the normal atmospheric CO2 treatment. Under normal CO2 levels (400 μL L‐1) nonstructural carbohydrate concentration (starch plus soluble sugar) was significantly higher in leaves of P‐deficient plants than in leaves of P‐sufficient plants in which nonstructural carbohydrate concentration exhibited a strong diurnal pattern. Under deficient P supply whole plant dry mass, symbiotic N2‐fixation parameters, and N and P accumulation were not enhanced by atmospheric CO2 enrichment. Phosphorus deficiency decreased nonstructural carbohydrate accumulation in nodules at the end of a 10‐day period in which functional activity was developing by 86% relative to P‐sufficient controls. While P deficiency elicited significant increases in the nonstructural carbohydrate concentration in leaves, it caused significant decreases in the nonstructural carbohydrate concentration in nodules over the diurnal cycle from 30 to 31 DAT. Collectively, these results indicate that the lack of a symbiotic N2‐fixation response to atmospheric CO2 enrichment by P‐deficient plants may be related to the decreased carbohydrate status of nodules. 相似文献
20.
Ingeborg F. Pedersen Peter Srensen Jim Rasmussen Paul J. A. Withers Gitte Holton Rubk 《植物养料与土壤学杂志》2019,182(4):541-551
We investigated the interacting effects of inorganic nitrogen and the main inorganic phosphorus form in dairy manure (dicalcium phosphate, CaHPO4) on growth, nutrient uptake, and rhizosphere pH of young maize plants. In a pot experiment, three levels of CaHPO4 (0, 167, and 500 mg P pot?1) were combined with nitrogen (637 mg N pot?1) applied at five NH4‐N : NO3‐N ratios (0 : 100, 25 : 75, 50 : 50, 75 : 25, and 100 : 0) and a nitrification inhibitor in a concentrated layer of a typical acid sandy soil from Denmark. 15N‐labeled NH4‐N was applied to differentiate the role of nitrification and to partition nitrogen uptake derived from NH4‐N. Among treatments including nitrogen, shoot biomass, rooting and phosphorus uptake were significantly higher at the five‐leaf stage when CaHPO4 was applied with NH4‐N : NO3‐N ratios of 50 : 50 and 75 : 25. In these treatments, rhizosphere pH dropped significantly in direct proportion with NH4‐N uptake. The fertilizers in the concentrated layer had a root‐inhibiting effect in treatments without phosphorus supply and in treatments with pure NO3‐N or NH4‐N supply. Increased nitrogen uptake as NH4‐N instead of NO3‐N reduced rhizosphere pH and enhanced acquisition of applied CaHPO4 by young maize plants, which may have positive implications for the enhanced utilization of manure phosphorus. 相似文献