Hyperaccumulator Research Articles

Cellulose Deficiency Is Enhanced on Hyper Accumulation of Sucrose by a H+-Coupled Sucrose Symporter.

In order to understand factors controlling the synthesis and deposition of cellulose, we have studied the Arabidopsis (Arabidopsis thaliana) double mutant shaven3 shaven3-like1 (shv3svl1), which was shown previously to exhibit a marked cellulose deficiency. We discovered that exogenous sucrose (Suc) in growth medium greatly enhances the reduction in hypocotyl elongation and cellulose content of shv3svl1 This effect was specific to Suc and was not observed with other sugars or osmoticum. Live-cell imaging of fluorescently labeled cellulose synthase complexes revealed a slowing of cellulose synthase complexes in shv3svl1 compared with the wild type that is enhanced in a Suc-conditional manner. Solid-state nuclear magnetic resonance confirmed a cellulose deficiency of shv3svl1 but indicated that cellulose crystallinity was unaffected in the mutant. A genetic suppressor screen identified mutants of the plasma membrane Suc/H(+) symporter SUC1, indicating that the accumulation of Suc underlies the Suc-dependent enhancement of shv3svl1 phenotypes. While other cellulose-deficient mutants were not specifically sensitive to exogenous Suc, the feronia (fer) receptor kinase mutant partially phenocopied shv3svl1 and exhibited a similar Suc-conditional cellulose defect. We demonstrate that shv3svl1, like fer, exhibits a hyperpolarized plasma membrane H(+) gradient that likely underlies the enhanced accumulation of Suc via Suc/H(+) symporters. Enhanced intracellular Suc abundance appears to favor the partitioning of carbon to starch rather than cellulose in both mutants. We conclude that SHV3-like proteins may be involved in signaling during cell expansion that coordinates proton pumping and cellulose synthesis.

Phytoremediation of heavy metals using Brassica juneca-A Review

Remediation of contaminated sites with toxic and heavy metals is particularly a challenging task. Therefore pre-treatment is needed before the discharge of these effluents. Among all method investigated presently, Phytoremediation is found to be an emerging and most innovative tool for removal of environmental contaminants such as heavy metals, trace elements, radioactive compounds and organic compounds from soil or water. It has been proposed as a cost-effective and environmental friendly technique. It involves the use of either naturally occurring metal hyper accumulator plants or genetically engineered plants. Indian mustard known as Brassica juncea is well known hyper accumulator. This paper aims to compile some information about sources of heavy metals and their toxicity. It also reviews deeply about phytoremediation technology, including the heavy metal uptake mechanisms and several case studies associated with Brassica juneca.

Vochysia guatemalensis Donn. Smith, an alternative species for reforestation on acid tropical soils

Vochysia guatemalensis Donn. Smith is a native species commonly used in small-scale reforestation programs in Costa Rica recognized for its fast growth under acidic and unfertile soil conditions. This study aimed to evaluate the nutrient concentration dynamics on individual trees of V. guatemalensis of increasing ages, in order to improve the understanding some aspects of its ecology as well as management of this tree species. Nutrient (N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, and B) and Al concentration in stems, branches and foliage were measured using false time series (also known as chronosequences) in 13 different tree stands (2–21 years) found in the Caribbean lowlands of Costa Rica. N, K and S concentrations in the stems showed a significant inverse relationship with DBH; while P, S, and Cu foliar contents increased with DBH. Average foliar concentrations of N, Ca, K, Mg, Fe, Zn, Mn, B, and Al showed little or no variation with tree growth. Foliar Al concentration (21, 297–28, 826 mg kg−1) was higher than previously reported as toxic for non-Al accumulating species (<1000 mg kg−1), confirming V. guatemalensis as an Al hyper accumulator. Our results reinforce the possibility of using V. guatemalensis for timber production, especially to improve the income of small farmers farming on very acidic soils. The nutrient concentrations that were obtained for different tree components provide baseline information for further studies where the objective is to evaluate the nutritional status of a site.

Role of Biotechnology in Phytoremediation

Phytoremediation, the use of plants and their associated microbes to accumulate, detoxify and/or stabilise contaminants, is an environment-friendly and sustainable means of remediating contaminated soil and water. Phytoremediation has been an important aspect of constructed wetlands, which have been used successfully to detoxify large volumes of wastewater with dilute concentrations of contaminants, including petroleum, hydrocarbons, chlorinated solvents, pesticides, explosives, heavy metals and radio nucleids. The most important requirement for Phytoremediation is the use of fast growing high biomass plants that are capable of uptake and accumulation of large amounts of toxic metals in their aboveground harvestable parts. In recent years major scientific progress has been made in understanding the physiological mechanism of metal uptake and transport in these plants. Since most metal hyper accumulators are slow growing and have low biomass, bioengineering of non accumulators having high biomass is essential for effective phytoremediation. Plants adopted for phytoremediation are usually found to exhibit the specific property due to the presence of the special genes coding for it. These plants are usually seen in area where metal ores exist. The genes responsible for this resistance by such plants are isolated and expressed in wide variety of transgenic plants so that they can be made resistant as well. This increases the number of plant species that can be used for such purpose. It is also possible with the help of biotechnology to increase the gene expression for maximum resistance. Certain plants are seen to show increased resistance under the presence of certain microbes. Biotechnology makes it possible to isolate such microbes and enrich the soil so as to enhance the phytoremediation by respective plants. This paper reviews the biotechnological approaches to improve plants’ ability to tolerate different pollutants and phytoremediation efficiency and highlights future challenges

Hyper Accumulation of Arsenic in Mutants of Ochrobactrum tritici Silenced for Arsenite Efflux Pumps.

Ochrobactrum tritici SCII24T is a highly As-resistant bacterium, with two previously described arsenic resistance operons, ars1 and ars2. Among a large number of genes, these operons contain the arsB and Acr3 genes that encode the arsenite efflux pumps responsible for arsenic resistance. Exploring the genome of O. tritici SCII24T, an additional putative operon (ars3) was identified and revealed the presence of the Acr3_2 gene that encodes for an arsenite efflux protein but which came to prove to not be required for full As resistance. The genes encoding for arsenite efflux pumps, identified in this strain, were inactivated to develop microbial accumulators of arsenic as new tools for bioremediation. Six different mutants were produced, studied and three were more useful as biotools. O. tritici wild type and the Acr3-mutants showed the highest resistance to As(III), being able to grow up to 50 mM of arsenite. On the other hand, arsB-mutants were not able to grow at concentrations higher than 1 mM As(III), and were the most As(III) sensitive mutants. In the presence of 1 mM As(III), the strain with arsB and Acr3_1 mutated showed the highest intracellular arsenic concentration (up to 17 ng(As)/mg protein), while in assays with 5 mM As(III), the single arsB-mutant was able to accumulate the highest concentration of arsenic (up to 10 ng(As)/mg protein). Therefore, arsB is the main gene responsible for arsenite resistance in O. tritici. However, both genes arsB and Acr3_1 play a crucial role in the resistance mechanism, depending on the arsenite concentration in the medium. In conclusion, at moderate arsenite concentrations, the double arsB- and Acr3_1-mutant exhibited a great ability to accumulate arsenite and can be seen as a promising bioremediation tool for environmental arsenic detoxification.

Effect of EDTA and Tannic Acid on the Removal of Cd, Ni, Pb and Cu from Artificially Contaminated Soil by Althaea rosea Cavan

In this study an ornamental plant of Althaea rosea Cavan was investigated for its potential use in the removal of Cd, Ni, Pb and Cu from an artificially contaminated soil. Effect of two different chelating agents on the removal has also been studied by using EDTA (ethylenediaminetetracetic acid) and TA (tannic acid). Both EDTA and TA have led to higher heavy metal concentration in shoots and leaves compared to control plants. However EDTA is generally known as an effective agent in metal solubilisation of soil, in this study, TA was found more effective to induce metal accumulation in Althaea rosea Cavan under the studied conditions. In addition to this, EDTA is toxic to some species and restraining the growth of the plants. The higher BCF (Bio Concentration Factor) and TF (Translocation Factor) values obtained from stems and leaves by the effects of the chemical enhancers (EDTA and TA) show that Althaea rosea Cavan is a hyper accumulator for the studied metals and may be cultivated to clean the contaminated soils.

Phytoextraction: Using Brassica as a Hyper Accumulator

Phytoextraction is a cost-effective method that could be an alternative to remediate polluted sites. Growth performance, biochemical, enzymatic activity, accumulation, translocation and mobility of arsenic form soil to root and leaves were studied in co-cultivated hyper accumulator (Brassica juncea) and hypo accumulator (Abelmuscus esculentus) at various levels of arsenic. B.juncea accumulated fourfold and fivefold arsenic in roots, shoots and leaves, respectively than Abelmuscus esculentus L. A. esculentus seedlings when cultivated alone were seen sensitive to arsenic with decrease growth, poor values of accumulation factor, translocation factor and mobility of metal. But the same plant when cocultivated with Brassica juncea there is no toxicity symptoms and reduction of growth, values of Accumulation factor, translocation factor and mobility of metal. This is well understand that Brassica juncea showing higher accumulation of nickel, more translocation of arsenic from root to shoot and good mobility of arsenic was increased form level 1 to level 3, It was revealed that the accumulation of arsenic was more in root and shoot of B. juncea than A. esculentus. It is inferred from the present study that A. esculentus is a hypo accumulator and is sensitive to arsenic. When co-cultivated with Brassica juncea showing less of metal toxicity because Brassica juncea being hyper accumulator of arsenic, accumulate more metal and save Abelmuscus esculentus.

Root cell wall polysaccharides are involved in cadmium hyperaccumulation in Sedum alfredii

The role of polysaccharide modification in metal accumulation in hyperaccumulators is still unknown. Our aim was to compare the differences in the role of root cell-wall polysaccharides in cadmium (Cd) accumulation between hyperaccumulating (HE) and non-hyperaccumulating ecotype (NHE) of Sedm alfredii. Hydroponic experiments were performed to characterize root-to-shoot Cd translocation, cadmium species and polysaccharide modification in root cell-wall of S. alfredii using stable isotope tracing, X-ray absorption near edge structure and immunofluorescence localization techniques. Cd absorbed was more readily available for transport to the shoots by the HE roots than by the NHE roots, which is confirmed by a 6-fold higher 113Cd concentration in xylem sap. Root Cd efflux originated mainly from the cell walls. The concentration of cell-wall polysaccharides and activity of pectin methylesterase were higher in the NHE than in the HE in the absence of Cd, and even higher in the presence of Cd. More pectins were methylated in the HE than in the NHE, indicating more free pectic acid residues in the NHE. The cell-wall-bound Cd was retained more tightly in the NHE than in the HE. Cadmium hyperaccumulation by HE of S. alfredii is associated with its enhanced Cd flux into the xylem, which is partly regulated by cell-wall polysaccharide modification in roots.

Evaluating Different Weeds for Phytoremediation Potential Available in Tannery Polluted Area by Conducting Pot and Hydroponic Experiments

The pot experiments were conducted to determine and compare the toxic effects of Chromium, Copper, Cadmium, Nickel and Lead on different parameters like shoot length, number of branches and area of leaf on different wild weedCannabis sativa, Solanumnigrum and Chenopodium album. The investigated amounts of metal were in the range of 7 different concentrations i.e. 5ppm, 10ppm,50ppm,100ppm,200ppm,300ppm and 350ppm.The average toxicity increases with increase in the concentration of metals but in certain cases variations were observed in toxicity parameters. The morphological response in Cannabis sativa showed that most of the changes on the morphological characteristics were observed at 100 ppm. The shoot length, leaf area and number of branches decrease at 100 ppm and above. The maximum variations as compared to other metals were shown in copper stress condition. In Chenopodium album all the metals except lead show morphological variation with increase in metal concentration. The morphological toxicity increases with increase in metal concentration. The overall pollen fertility analysis shows that metal exposure leads to the development of sterile pollens. This shows the relative toxic effect of metals on the pollen fertility. In the hydroponic experiments, the Chromium metal exposure on the weed Cannabis sativa(C) and (P) for 15 days shows decrease in the amount of Chromium in the medium detected throughdiphenylcarbazide method, which shows the hyper accumulation of chromium by these weeds.

Effect of Cadmium (Cd) stress on the germination and early seedling growth of Mustard seeds (Brassica campestris L.): deducing a dose - response relationship

Due to severe heavy nmetals contamination in agricultural soil worldwide, several studies specifically focused on the development of metal accumulating crop plants, which can maintain their optimum growth and production in contaminated soil. Mustard plants (Brassica campestris L.) are in generally considered as the hyper accumulator, can be grown advantageously for phytoremediation of the lands contaminated by industrial wastes. Therefore, the effect of varied cadmium (Cd) concentrations on the germination and initial growth of mustard seeds were investigated under controlled laboratory conditions. Results showed a differential response of mustard seeds under varied Cd concentrations. The lower levels of Cd affected the mustard seeds positively or neutrally; but the higher Cd levels showed significant adverse effect. We conclude that as mu_tard being a hyper-accumulator of several metals can only be grown at lower Cd levels for their optimum performance.

Heavy Metals Uptake by Select Plant Species in the Landfill Area of Štěpánovice, Czech Republic

Vegetation can be used as bioindicators of site pollution by identifying the mobilization of heavy metals. This study was conducted to screen plants growing in a landfill site to determine their potential for metal accumulation. Plants selected were the Tanacetum vulgare and Lycopersicon esculentum. Based on results, it may be concluded that Tanacetum vulgare can tolerate and sequester Cd from the soil. None of the plants were identified as metal hyper accumulators. However, Tanacetum vulgare was most effective in taking up metals and showed a higher enrichment coefficient of heavy metals, indicating its higher accumulation ability.

Phytoaccumulation of Chromium and Copper by Mentha spicata L.

Phytoaccumulation of Chromium and Copper by Mentha spicata L. This paper reports a study of heavy metal absorption by Mentha spicata. M. spicata was grown in garden soil. The soil was treated with different concentrations (20 mg/l, 40 mg/l, 60 mg/l and 80 mg/l)of chromium and copper solutions. The effect of the application of the above two heavy metals was studied after 10 days of the treatment.Chromium and copper exerted toxic effects on the growth and physical parameters of Mentha spicata. M. spicata functioned as a hyper accumulator of chromium and copper. The results indicated that the reduction of growth parameters was inversely related to concentration of the heavy metals.

Studying the Relationship between Acyl-CoA-Binding Protein 2 and Lysophospholipase 2 in Arabidopsis thaliana and Their Importance in Recycling of Cadmium

A major environmental concern due to dispersal of industrial and urban wastes generated by human activities is the contamination of soil. A wide range of inorganic and organic compounds cause contamination, these include heavy metals, combustible and putriscible substances, hazardous wastes, explosives and petroleum products. Major component of inorganic contaminates are heavy metals .Phytoremediation is a group of technologies that used by plants to remove, degrade or immobilize environmental toxins. This technology largely focused on the use of plants for accelerating degradation of organic contaminants. But in addition to use of plant for soil remediation, hyper accumulator plants can be used for recycling of metals from soil. Hyper accumulator plant express special proteins that help them to tolerate the high concentration of metals.in this experiment we discussed the relationship between acyl-CoA-binding protein 2 and lysophospholipase 2 and showed why this two proteins work together.

16S rDNA analysis of bacterial communities associated with the hyper accumulator Arabidopsis halleri grown on a Zn and Cd polluted soil

Having a glimpse of the relationships between the zinc and cadmium hyper accumulator Arabidopsis halleri and its rhizospheric bacteria may represent an interesting step towards the implementation of a rhizoremediation strategy based on this plant. Until now, these relationships remained unraveled. This work aimed to give some insights into the composition of the bacterial communities surrounding A. halleri when it grows on a soil harboring elevated amounts of zinc and cadmium, as well as into the influence that plant roots may exert on them. Industrial highly polluted soils containing different amounts of zinc and cadmium and surrounding A. halleri plants were sampled and their bacterial contents were harvested at various distances from A. halleri root system. Genetic diversity was assessed through DNA extraction, PCR amplification, 16S rDNA libraries construction, RFLP analysis and partial sequencing. Nine mini-libraries of hundred clones each were established and analyzed. Up to 481 independent clones were sequenced and identified at genus level. Twelve genera among 48 were found particularly well represented in the different sub-fractions analyzed. At class level, ten different classes were identified. Alpha-proteobacteria, Gamma-proteobacteria, Flavobacteria and Sphingobacteria were the main contributors to flora diversity. In the less polluted soil, roots proximity seems to affect negatively Alpha-proteobacteria and Flavobacteria and positively Gamma-proteobacteria. A rhizospheric selection limited to some specific genera was also observed when pollution raised.

Inoculation of selenium hyperaccumulator Stanleya pinnata and related non‐accumulator Stanleya elata with hyperaccumulator rhizosphere fungi—investigation of effects on Se accumulation and speciation

Little is known about how fungi affect elemental accumulation in hyperaccumulators (HAs). Here, two rhizosphere fungi from selenium (Se) HA Stanleya pinnata, Alternaria seleniiphila (A1) and Aspergillus leporis (AS117), were used to inoculate S. pinnata and related non-HA Stanleya elata. Growth and Se and sulfur (S) accumulation were analyzed. Furthermore, X-ray microprobe analysis was used to investigate elemental distribution and speciation. Growth of S. pinnata was not affected by inoculation or by Se. Stanleya elata growth was negatively affected by AS117 and by Se, but combination of both did not reduce growth. Selenium translocation was reduced in inoculated S. pinnata, and inoculation reduced S translocation in both species. Root Se distribution and speciation were not affected by inoculation in either species; both species accumulated mainly (90%) organic Se. Sulfur, in contrast, was present equally in organic and inorganic forms in S. pinnata roots. Thus, these rhizosphere fungi can affect growth and Se and/or S accumulation, depending on host species. They generally enhanced root accumulation and reduced translocation. These effects cannot be attributed to altered plant Se speciation but may involve altered rhizosphere speciation, as these fungi are known to produce elemental Se. Reduced Se translocation may be useful in applications where toxicity to herbivores and movement of Se into the food chain is a concern. The finding that fungal inoculation can enhance root Se accumulation may be useful in Se biofortification or phytoremediation using root crop species.

EDTA Enhanced Phytoremediation of Copper Contaminated Soils Using Chickpea (Cicer aeritinum L.)

The goal of this research was to determine whether or not chickpea (Cicer arietinum L.), commonly known as Garbanzo beans, is a hyper accumulator for copper (Cu) in contaminated soils amended with EDTA. Statistical analysis (2 tailed Pearson Correlation) revealed significant correlations between: Translocation index and stem biomass (r = 0.859**; p < 0.01); Tolerance index and stem biomass (r = 0.762**; p < 0.01); and bioconcentration factor of stem/soil and soil Cu concentration (r = -0.545*; p < 0.05). Therefore, C. arietinum seems to be a cost-effective and environmentally friendly hyperaccumulator for Cu at 100 ppm Cu and 10 mM EDTA.

Phytoaccumulation of iron by callus tissue of Clerodendrum indicum (L)

Clerodendrum indicum (L.) is one of the important medicinal plants, originating in India. The plant is used as medicine for bronchitis, asthma and different immunological disease. Micro-propagation is a quick method, producing a huge number of plants. Apical leaf of Clerodendrum indicum (L.) was used as an explant for callogenesis. The combinations of different plant growth regulators (2,4-D, NAA, KN) in MS (Murashige and Skoog) medium produced two types of calli: one was friable and loose and the other was green, embryogenic and compact. Heavy metals cause pollution and health hazards. The plant absorbs heavy metals, which is very useful for controlling environmental pollution. Iron is a major nutrient for both plants and animals, but hyper accumulation of iron is injurious to health. Calli were used to study the optimum conditions of iron uptake in presence of different chemical environments. The different environments were created by using different chemical reagents such as (HCL, HNO3, H3PO4 and KNO3). Iron (III) was spiked with radioactive Fe-59 and dynamics of uptake was followed by measuring radioactivity by gamma-ray spectrometer. The best condition of iron uptake corresponded to 1 mol L−1 KNO3 after 4 hour of equilibration.

Bioaccumulation of heavy metal uptake by two different Vetiver grass (Vetiveria zizanioides and Vetiveria nemoralis) species

The efficiency of Cd, Pb and Zn uptake of upland vetiver grass (Vetiveria nemoralis) ecotypes as Kamphaeng Phet1, Prajuab Kirikhun, and Ratchaburi and lowland vetiver grass (Vetiveria zizanioides) ecotypes consisting of Kamphaeng Phet2, Mae Hongson, and Surat Thani were compared under sterile condition for interferent repudiation. The results showed that the total Cd accumulation of V. zizanioides was in the order of Kamphaeng Phet1 > Ratchaburi > Prajuab Kirikhun ecotype and in V. nemoralis was Mea Hongson approximately Kamphaeng Phet2 > Surat Thani (p < 0.05). All the vetiver grass ecotypes preferentially accumulated Pb in roots than shoots, with the rate of translocation less than 1. However, the efficiency of Cd and Zn translocation was different, depending on each vetiver ecotype. In addition, all vetiver ecotypes, except Kamphaeng Phet1, displayed high capability of Zn uptake in both shoots and roots after 7 days. Therefore, the vetiver plant can be considered a good “hyperaccumulator” only for Zn. Key words: Vetiveria zizanioides, Vetiveria nemoralis, total accumulation rate (TAR), transport factor (TF).

Study on the accumulation of copper from soil by shoots and roots of some selective plant species

Phytoextraction, the use of plants to extract toxic metals from contaminated soils, has emerged as a cost effective, environment friendly clean up alternative. The present study aimed to find a suitable plants species for use in cleaning up Cu from copper contaminated soil. Soil is artificially polluted by different concentration of Cu and the effects were studied in four verities of plant Triticumaestivum L (corn),Abelmoschusesculentus L, Basella alba L, and Solanumlycopersicum L (vegetables) from different family Poaceae, Malvaceae, Basellaceae and Solanaceae respectively those usually abundantly grow in Bangladesh. Atomic absorption spectrophotometer (AAS) was used for analysis of heavy metal in soil and plant samples.Results demonstrated that plant species were differing significantly in Cu uptake. Wheat plants (Triticumaestivum L) were more tolerant to the conditions tested with the highest dry matter production and no visual toxicity symptoms. The efficiency of Cu uptake from soil by Triticumaestivum L was observed by roots (803.14 mg kg-1) and shoots (418.43 mg kg-1). Triticumaestivum L totally accumulated 1221.57 mg kg -1 in dry weight and demonstrated as a hyper accumulator, other plants were not accumulated copper as higher as wheat. Thus Triticumaestivum L can be used for remediation of Cu polluted area.

Hyperaccumulation of (18)F-FDG in order to differentiate solid pseudopapillary tumors from adenocarcinomas and from neuroendocrine pancreatic tumors and review of the literature.

Solid pseudopapillary tumors (SPT) are rare, unique pancreatic tumors with benign entity and low malignant potential. Limited information is available in the literature reporting their accumulation of fluorine-18 fluoro deoxyglucose ((18)F-FDG) using positron emission tomography/computed tomography (PET/CT). The aim of this retrospective study was to define t he uptake-accumulation of (18)F-FDG PET/CT in a comparatively large cohort of SPT, and to compare their uptake with the uptake of (18)F-FDG in pancreatic ductal adenocarcinomas (PAC) and neuroendocrine tumors (PNET). Between June 2007 and January 2013, 18 pathologically proven SPT were identified from the total of patients studied by PET/CT in our Center, including 13 women and 5 men, aging from 23 to 56 years old (mean age, 38.5 years). Malignant SPT was histologically classified using the WHO criteria. Eighty-six PAC patients and 28 PNET patients were also identified and included in this study for comparison. Positron emission tomography results were considered as positive if focal accumulation of (18)F-FDG exceeded the surrounding normal pancreatic tissue. Regions of interest were drawn on the pancreatic lesions, and the maximal standardized uptake values (SUVmax values) were calculated. The mean values of SUVmax were compared with independent-samples t test or with the nonparametric Mann-Whitney U method. Correlation of SUVmax values and tumor size were analyzed in cases of SPT. Receiver operating characteristics (ROC curve) were used to study the efficiency of SUV values for the differential diagnosis between SPT versus (vs) PAC and SPT vs PNET. A value of P<0.05 was considered statistically significant. All SPT cases were (18)F-FDG-PET positive, with SUVmax values ranging from 3.5-18.3. The SUVmax values of SPT had poor correlation with tumor size, and no significant difference by gender and age. Areas under the curve ROC were 0.619 and 0.526, respectively for the differentiation of SPT from PNET and PAC tumors. Five SPT tumors were malignant, and exhibited relatively low (18)F-FDG uptake (SUVmax range, 3.0-4.5) except a tumor after recurrence (SUVmax 17.7). Images of CT were of low dose and thus were not evaluated. In conclusion, our results suggest that SPT benign or malignant are consistently hyperaccumulating (18)F-FDG above SUVmax 3. Differentiation from PAC and PNET if only based on the higher SUVmax values was not possible but if based on lower SUVmax, of ≤2.6 (in 14%) and ≤2.5 (in 21,4%) of PAC and PNET, respectively, these pancreatic tumors could be differentiated from SPT.