Atriplex Lentiformis Research Articles

Monitoring the temporal variations of plant stress using the air pollution tolerance index in the Sejzi industrial area (Isfahan, Iran).

The objective of this study was to screen air pollution-induced stress in some plant species in the Sejzi industrial region (Isfahan, Iran). An assessment of APTI and other physiological and biochemical features of significant species in the area was conducted across three seasons: spring, summer, and autumn. The physiological and biochemical factors of the following species were evaluated: Limonium persicum, Atriplex lentiformis, Nitraria schoberi, Haloxylon persicum, Tamarix hispida, Zygophyllum atriplicoides, Karelinia caspica, and Prosopis farcta. The physiological factors assessed included acidity and relative humidity content, while the biochemical factors assessed included proline, sugar, ascorbic acid, and total chlorophyll. Subsequently, a thorough evaluation was carried out on the species under investigation to ascertain their biomonitors' capabilities and APTI. The study findings indicated that the species P. farcta, N. schoberi, and K. caspica consistently had high APTI values during the spring, autumn, and summer seasons, classifying them as tolerant plant species. Conversely, the observed traits showed significant fluctuations across the seasons. The investigation's findings indicate that the species L. persicum, N. schoberi, and K. caspica exhibit higher annual averages of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid compared to other species. The examination of the annual variation in the tolerance levels of plant species to pollution ranked from highest to lowest was as follows: N. schoberi, P. farcta, K. caspica, Z. atriplicoides, H. persicum, T. hispida, L. persicum, and A. lentiformis. Moreover, based on the annual average, the primary determinants that impact the APTI in the species being studied include ascorbic acid (35%), leaf acidity (19%), total chlorophyll content (35%), and relative humidity content (69%). Furthermore, a distinct and significant correlation was found between proline and sugar levels and the annual APTI values. Additionally, the species P. farcta had the highest API compared to other species. The study revealed the high potential of some plant species against air pollution induced stress which can be used in air and dust pollution management in the region.

Habitat-specific allocations of elements in Atriplex lentiformis seeds indicate adaptation to metal toxicity.

Self-sustaining vegetation in metal-contaminated areas is essential for rebuilding ecological resilience and community stability in degraded lands. Metal-tolerant plants originating from contaminated post-mining areas may hold the key to successful plant establishment and growth. Yet, little is known about the impact of metal toxicity on reproductive strategies, metal accumulation, and allocation patterns at the seed stage. Our research focused on the metal tolerant Atriplex lentiformis. Specifically, we examined the effects of toxic metal(loid) concentration in soils on variability in its reproductive strategies, including germination patterns, elemental uptake, and allocation within the seeds. We employed advanced imaging techniques like synchrotron X-ray fluorescence microscopy (2D scans and 3D tomograms) combined with inductively coupled plasma mass spectrometry to reveal significant differences in metal(loid) concentration and distribution within the seed structures of A. lentiformis from contrasting habitats. Exclusive Zn hotspots of high concentrations were found in the seeds of the metallicolous accession, primarily in the sensitive tissues of shoot apical meristems and root zones of the seed embryos. Our findings offer novel insights into phenotypic variability and metal tolerance and accumulation in plants from extreme environments. This knowledge can be applied to enhance plant survival and performance in land restoration efforts.

Nutritive value and aerobic stability of whole quail bush and date waste silage ensiled at different compositions and the role of hetero-fermentative lactic acid bacteria

Nutritive value and aerobic stability of whole quail bush and date waste silage ensiled at different compositions and the role of hetero-fermentative lactic acid bacteria

Zinc accumulation in Atriplex lentiformis is driven by plant genes and the soil microbiome

Successful phytoremediation of acidic metal-contaminated mine tailings requires amendments to condition tailings properties prior to plant establishment. This conditioning process is complex and includes multiple changes in tailings bio-physico-chemical properties. The objective of this project is to identify relationships between tailings properties, the soil microbiome, and plant stress response genes during growth of Atriplex lentiformis in compost-amended (10 %, 15 %, 20 % w/w) mine tailings. Analyses include RNA-Seq for plant root gene expression, 16S rRNA amplicon sequencing for bacterial/archaeal communities, metal concentrations in both tailings and plant organs, and phenotypic measures of plant stress. Zn accumulation in A. lentiformis leaves varied with compost levels and was the highest in the intermediate treatment (15 %, TC15). Microbial analysis identified Alicyclobacillus, Hydrotalea, and Pseudolabrys taxa with the highest relative abundance in TC15, and these taxa were strongly associated with Zn accumulation. Furthermore, we identified 190 root genes with significant gene expression changes. These root genes were associated with different pathways including, abscisic acid and auxin signaling, defense responses, ion channels, metal ion binding, oxidative stress, transcription regulation, and transmembrane transport. However, root gene expression changes were not driven by the increasing levels of compost. For example, there were 15 genes that were up-regulated in TC15, whereas 106 genes were down-regulated in TC15. The variables analyzed explained 86 % of the variance in Zn accumulation in A. lentiformis leaves. Importantly, Zn accumulation was driven by Zn shoot concentrations, leaf stress symptoms, plant root genes, and microbial taxa. Therefore, our results suggest there are strong plant-microbiome associations that drive Zn accumulation in A. lentiformis and different plant gene pathways are involved in alleviating varying levels of metal stress. Future work is needed to gain a mechanistic understanding of these plant-microbiome interactions to optimize phytoremediation strategies as they will govern the success or failure of the revegetation process.

Effect of jasmonic acid on the phytoremediation of dinitrophenol from wastewater by Solanum nigrum L. and Atriplex lentiformis (Torr.) S. Watson.

Phytoremediation is one of the best methods for cleaning up natural resources like water because plants are eco-friendly and safe for the ecosystem. Hyperaccumulators, e.g., Solanum nigrum L. and Atriplex lentiformis (Torr.) S. Watson, have been used to remove toxic metals from soil and water through phytoremediation techniques, but it is unknown if they can remove hazardous chemicals such as dinitrophenol (DNP), from wastewater. A hydroponic experiment was conducted to study the efficiency of S. nigrum and A. lentiformis in removing DNP from wastewater. Jasmonic acid (JAC) was applied to the tested plants in two doses, 0.25 and 0.50mmol, in an effort to better understand how it affects phytoremediation effectiveness. The growth of S. nigrum and A. lentiformis improved significantly (p < 0.05) by the foliar application of JAC. The applications of JAC1 and JAC2 significantly (p < 0.05) increased nutrient uptake and chlorophyll concentrations in S. nigrum and A. lentiformis plants. The foliar spraying of S. nigrum and A. lentiformis with JAC significantly (p < 0.05) increased the antioxidant enzymes activity, i.e., SOD and POD. The levels of osmoregulatory substances like proline and carbohydrates significantly (p < 0.05) increased after JAC was sprayed on S. nigrum and A. lentiformis plants. In the case of S. nigrum, the efficiency of DNP removal varied between 53 and 69%, with an average of 63%, while in the case of A. lentiformis, it varied between 47 and 62%, with an average of 56%. The removal efficiency of DNP reached 67 and 69% when S. nigrum was sprayed with JAC1 and JAC2. When JAC1 and JAC2 were sprayed on A. lentiformis, DNP removal efficiency rose from 47 to 60 and from 47 to 62%, respectively. S. nigrum and A. lentiformis plants can be grown normally and survive in dinitrophenol-contaminated water without showing any toxic symptoms. S. nigrum and A. lentiformis have a powerful antioxidant system and the ability to produce vital compounds that alleviate the stress caused by DNP toxicity. The findings are crucial for cleaning up polluted water and protecting the ecosystem's health from dangerous pollutants.

Spate irrigation slightly ameliorates an arid soil's quality, but tree planting enhances its characteristics

Spate irrigation (SI) is an appropriate technology to utilize the harvested floodwater, which besides providing the required water for plant consumption ameliorates the soil quality in arid and semi-arid areas. The long-term effects of SI on the soil quality, especially enzymatic and biological activities of rangelands and farm fields, remain virtually unknown. A desertification control project through floodwater spreading was initiated in the Gareh Bygone Plain (GBP) in the Province of Fars, Iran in 1983 with aims of augmenting groundwater, stabilizing the moving sand, and particularly improving the rangeland yield through SI. We have investigated the physico-chemical, biological and biochemical qualities of the soil in the spate-irrigated fields planted to river red gum (Eucalyptus camaldulensis Dehnh.), cooba (Acacia salicina Lindl.), and quail bush [Atriplex lentiformis (Torr.) (Wats.)], and a native rangeland and compared them with the same fields without SI. The loamy sand texture has changed to silt loam, which has improved water availability. Improvements have also occurred in the soil pH, organic carbon content, nutrients, enzymatic activities, and microbial respiration; however, the magnitude of these improvements varied among the different vegetative covers. Furthermore, the impacts of SI on soil functions enhanced by tree planting. The soil's higher fertility indicators, increased enzymatic activities and microbial respiration were attributed to the Eucalyptus plantation under SI by the principal component analysis (PCA). We recommend simultaneous implementation SI and tree planting in the arid and semi-arid regions for the enhancement of soil productivity.

Phytoremediation of dinitrophenol from wastewater by atriplex lentiformis: effect of salicylic acid

Quail bush [Atriplex lentiformis (Torr.) S. Wats] plants were used in removing 2, 4-dinitrophenol (DNP) from wastewater in a hydroponic experiment. The hydroponic system contained three doses of DNP, i.e., 0, 10, and 20 mg L−1. Quail bush plants were sprayed with 0.1 mM salicylic acid (SA) to study its role in resisting DNP toxicity. DNP significantly (p < 0.05) reduced plant growth. Exposure of A. lentiformis plants to 20 mg L−1 of DNP reduced the total chlorophyl and relative water content by 39 and 24%, respectively. SA improved the antioxidant defense in terms of ascorbate peroxidase (APX) and polyphenol oxidase (PPO) activities. SA alleviated DNP toxicity by enhancing the production of osmoprotectants, e.g.,proline, phenols, and carbohydrates. SA enhanced the removal efficiency of DNP and the highest removal efficiency (96%) was recorded in the plants sprayed with SA and grown on 10 mg L−1 of DNP. A. lentiformis is a halophytic plant that has good physiological characteristics to resist 2, 4-dinitrophenol toxicity in wastewaters and is qualified to purify water from these harmful compounds. Exogenous application of 0.1 mM SA increased the defense system in A. lentiformis against 2, 4-dinitrophenol toxicity and enhanced the removal efficiency.

Effect of Metal-resistant PGPB on the Metal Uptake, Antioxidative Defense, Physiology, and Growth of Atriplex lentiformis (Torr.) S.Wats. in Soil Contaminated with Cadmium and Nickel

Effect of Metal-resistant PGPB on the Metal Uptake, Antioxidative Defense, Physiology, and Growth of Atriplex lentiformis (Torr.) S.Wats. in Soil Contaminated with Cadmium and Nickel

Evaluation of rainwater harvesting and shrub establishment methods for sustainable watershed management in northern Afghanistan

Watershed rangelands in Northern Afghanistan provide various ecosystem services that support the local people’s livelihoods, but they are now highly degraded essentially due to the continuous high grazing pressure and recurrent droughts. Effects of shrub establishment method enhanced by water harvesting techniques to rehabilitate degraded rangelands have not been well addressed. The main goal of this study was to evaluate the impact of direct seeding and transplanting of seedlings in combination with semi-circular bunds on growth, yield, and survival rate of four shrub species (Atriplex halimus, Atriplex nummularia, Atriplex lentiformis, and Maireana brevifolia) under semi- arid conditions of Sayyad village, Khulm watershed. Survival rate (%), plant height, width, and plant length (cm) and plant cover (%) were measured for each plant over five occasions. A non-destructive reference unit was used to estimate biomass production. The results showed that growth attributes and biomass production of shrubs were consistently greater in the transplanting compared to direct seeding. On average, the plant length, width, height, volume, cover, and biomass production of transplanted shrubs were greater than direct-seeded shrubs by 24.3%, 8.6%, 8.7%, 121.5%, 13.8% and 34.1%, respectively. Biomass production of transplanted seedlings was the highest for A. nummularia (1313.5 g DM/plant) and A. halimus (800 g DM/plant). There was a strong correlation between plant biomass production and plant volume (R2Plant volume = 0.88) for the shrub A. nummularia, indicating that plant volume is a key variable for assessing biomass production for this species. Additionally, the survival rate of M. brevifolia was 100% in both planting methods, suggesting that based on better survival this halophytic plant has great potential when restoring degraded rangelands. Collectively, on the basis of better growth rates, yield, and survival, transplanting A. nummularia and A. halimus may enhance shrub establishment and contribute to the rehabilitation of sloping semi-arid degraded areas of Northern Afghanistan.

Nitrogen and Compost Enhanced the Phytoextraction Potential of Cd and Pb from Contaminated Soils by Quail Bush [Atriplex lentiformis (Torr.) S.Wats

Nitrogen and Compost Enhanced the Phytoextraction Potential of Cd and Pb from Contaminated Soils by Quail Bush [Atriplex lentiformis (Torr.) S.Wats

Macneill's Sootywing (Hesperopsis gracielae, Family: Hesperiidae): Life History Success Associated with Foodplant's Soil Moisture at Lower Colorado River Conservation Areas

Early life stages and adult MacNeill's sootywing (Hesperopsis gracielae MacNeill, Family: Hesperiidae), a small butterfly, were searched for at ten conservation/wildlife areas along the Lower Colorado River Valley. This butterfly can only complete development on quailbush (Atriplex lentiformis (Torr.) S. Watson, Family: Amaranthaceae). In most cases quailbush was intentionally planted at conservation areas for wildlife purposes. Evidence of sootywings was found at nine of the locations. A single location had low numbers of the larval food plant and this may have resulted in non-detection of the butterfly. Early life stages of sootywings were associated with quailbush that had statistically higher soil moisture at the plant base. Plants where early life stage sootywings were detected (n=41) averaged 63 ± SE 6.3% soil moisture, while those where sootywings were not detected (n=109) averaged 37 ± SE 4% soil moisture. Soil moisture and appropriate densities of quailbush appeared to be important attributes for support of MacNeill's sootywing populations. Size of quailbush and presence of nectar in the environment were not statistically important attributes in presence or abundance of sootywings.

Physiological response of diverse halophytes to high salinity through ionic accumulation and ROS scavenging

Salt stress induced modulations in different ionic ratios and ROS system were studied in ten halophytic species, namely Atriplex lentiformis, Tamarix aphylla, Sporobolus marginatus, Suaeda nudiflora, Urochondra setulosa, Arundo donax, Aeluropus lagopoides, Heliotropium ramossimum, Atriplex nummularia, Leptachloa fusca at salinity level of ECe ∼ 30 dSm−1 (≈300 mM NaCl) to explore their possible role in salt tolerance ability of these halophytes. These halophytes were categorized for their salt tolerance levels based on the ratios of Na+/K+, Na+/Ca2+, Na+/Cl− and Na + Cl/K + Ca. Variable responses were observed among all halophytes where Atriplex lentiformis had lowest leaf Na+/K+ (0.44) which is one of the best indicator of salt tolerance, Heliotropium ramossimum had lowest Na+/Ca2+ and Na+/Cl− (0.97 and 0.18), whereas Sporobolus marginatus had lowest Na + Cl/K + Ca (0.79). Specific enzymes activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were also assessed to get better comprehension of the ROS scavenging system under salinity in these halophytes. Urochondra setulosa showed highest APX and SOD activity followed by Atriplex lentiformis. Most efficient enzyme in degrading hydrogen peroxide i.e. CAT showed highest activity in Suaeda nudiflora followed by Atriplex nummularia and Urochondra setulosa, whereas Atriplex nummularia and Atriplex lentiformis showed higher POX activity. Significant variability in H2O2 and MDA content was also observed. These results possibly suggest higher inbuilt genetic potential of these halophytes to combat high salinity induced oxidative stress via higher antioxidant activities. Novelty statement: Halophytic plant adopt different strategies to cope up with the toxic ions and our studies show that the induction of antioxidant defense system to scavenge ROS, alongwith structural modifications in terms of lipid peroxidation and compartmentalization of toxic ions are the main strategies for tighter control of ion fluxes in the studied halophytes.

Chemical composition, ruminal degradation kinetics, and methane production (in vitro) of winter grass species

Information about the nutritive value, dry matter (DM) digestibility, and methane (CH4 ) emission potential of grass species is required for their optimal utilization in ruminant rations. The present study was designed: (i) to quantify the nutrient profile, mineral composition and in vitro dry matter digestibility (IVDMD) of winter grass species commonly available in northern Pakistan; and (ii) to measure the in vitro gas production (IVGP) and CH4 emission of the grass species during 72 h in vitro ruminal fermentation. Seven grass species, namely, Cenchrus ciliaris, Setaria anceps, Panicum antidotale, P. maximum, Pennisetum purpureum, Pennisetum orientale, and Atriplex lentiformis were assessed. A high level of variability (P < 0.001) was observed among grass species for the content of all measured nutrients, IVDMD, IVGP, and CH4 -production. Notably, the content (g kg-1 DM) of crude protein varied from 59.8 to 143.3, neutral detergent fiber from 560.3 to 717.9, IVDMD from 375.1 to 576.2, and 72 h cumulative IVGP from 97.6 to 227.4 mL g-1 organic matter (OM) and CH4 from 48 to 67 mL g-1 OM. Among the grasses, P. antidotale had greater content (g kg-1 DM) of crude protein (CP) (143.3), IVDMD (576.2), and 72 h cumulative IVGP (227.4 mL g-1 OM), and produced the smallest amount of total CH4 (48 mL g-1 OM) during 72 h fermentation. In contrast, A. lentiformis had the lowest content (g kg-1 DM) of CP (59.8), IVDMD (375.1), 72 h cumulative IVGP (97.6 mL g-1 OM), and produced a greater amount of total CH4 (67 mL g-1 OM) during 72 h fermentation. The findings of the current study highlight that it is possible to select and further develop grass species with high nutritional value and lower CH4 -production, which can improve livestock productivity, farm profitability, and long-term environment sustainability. © 2020 Society of Chemical Industry.

Comparing Kinetics of Xylem Ion Loading and Its Regulation in Halophytes and Glycophytes.

Although control of xylem ion loading is essential to confer salinity stress tolerance, specific details behind this process remain elusive. In this work, we compared the kinetics of xylem Na+ and K+ loading between two halophytes (Atriplex lentiformis and quinoa) and two glycophyte (pea and beans) species, to understand the mechanistic basis of the above process. Halophyte plants had high initial amounts of Na+ in the leaf, even when grown in the absence of the salt stress. This was matched by 7-fold higher xylem sap Na+ concentration compared with glycophyte plants. Upon salinity exposure, the xylem sap Na+ concentration increased rapidly but transiently in halophytes, while in glycophytes this increase was much delayed. Electrophysiological experiments using the microelectrode ion flux measuring technique showed that glycophyte plants tend to re-absorb Na+ back into the stele, thus reducing xylem Na+ load at the early stages of salinity exposure. The halophyte plants, however, were capable to release Na+ even in the presence of high Na+ concentrations in the xylem. The presence of hydrogen peroxide (H2O2) [mimicking NaCl stress-induced reactive oxygen species (ROS) accumulation in the root] caused a massive Na+ and Ca2+ uptake into the root stele, while triggering a substantial K+ efflux from the cytosol into apoplast in glycophyte but not halophytes species. The peak in H2O2 production was achieved faster in halophytes (30 min vs 4 h) and was attributed to the increased transcript levels of RbohE. Pharmacological data suggested that non-selective cation channels are unlikely to play a major role in ROS-mediated xylem Na+ loading.

Growth and biochemical changes in quail bush (Atriplex lentiformis (Torr.) S.Wats) under Cd stress

Halophytes have several advantages to be more effective in metal phytoextraction. Little is known about the Cd-phytoextraction potential of Atriplex lentiformis under different levels of Cd. Seven levels of Cd (0, 40, 80, 120, 160, 200, and 240mg per kg of soil) were added to A. lentiformis plants grown on pots filled with 5kg of sandy loam soil. A. lentiformis plants achieve different defense mechanisms to meet the high concentration of Cd in the soil and plant. These mechanisms include reducing the number and area of leaves, minimizing chlorophyll synthesis, and enhancing synthesizing of oxalic acid, phenols, and proline. The critical point of Cd was 9.35 and 183mgkg-1 for available soil Cd and leaves concentrations, respectively. The maximum level of Cd displayed a 66% decrease in the chlorophyll content of the leaves. On the other hand, the oxalic acid, phenols, and proline in the leaves were increased significantly by 129, 100, and 200% when Cd increased from 0 to 240mg. The tested plant removed 3.6% of the total soil Cd under the low Cd concentration (40mg) but under the high level of Cd (240mg), it only removed a negligible amount of soil Cd (0.74%). The current study confirmed that A. lentiformis plants lost the ability to cleanup Cd from contaminated soil under the high levels of contamination due to the high reduction in the production of dry matter.

Chemical Composition of Essential Oil from Atriplex lentiformis Leaves

Chemical Composition of Essential Oil from Atriplex lentiformis Leaves

Nitrogen fertilization: Effect on Cd-phytoextraction by the halophytic plant quail bush [Atriplex lentiformis (Torr.) S. Wats

Remediation of metal polluted sites by traditional, physical and chemical methods demands large investments of economic and technological resources compared to green remediation. Halophytic plants have been suggested to be more effective in the phytoextraction of metals from the contaminated soils compared to salt-sensitive crop plants. Pot experiment was conducted to study the accumulation of cadmium (Cd) by the Atriplex lentiformis plants when treated with different rates of nitrogen fertilizer. Nitrogen was applied to the soil at rate of 0, 100, 200, 300 and 400mgkg−1. Increasing the level of nitrogen from 0 to 400mgNkg−1 increased the dry biomass of roots and shoots of the studied plant by 75 and 27.5%, respectively. The application of N increased the chlorophyll by 100% and leaf area index by 50% and this led to increase in the photosynthesis and plant growth. The A. lentiformis plants tolerate the high levels of Cd in the soil and plant tissues. Under metal stress conditions, the studied plant contained large amount of organic compounds e.g., oxalic acid, proline and phenols. These organic compounds had negative effect on the plant growth and Cd accumulation in the aboveground parts of the plant. When 400mgNkg−1 was added, the chlorophyll increased by 100% and the proline, phenols and oxalic acid decreased by 33, 50 and 30%, respectively compared to the control treatment. The fertilization of A. lentiformis plants with the highest rate of nitrogen enabled the plants to remove 7.93% of the total soil Cd during a period of 105days. Nitrogen mitigated the effect of metal stress and increased the accumulation of Cd in the aboveground parts of A. lentiformis plants. The fertilization of A. lentiformis with nitrogen could be an effective tool to enhance Cd-phytoextraction from polluted sites.

RESPONSE OF TWO SPECIES OF ATRIPLEX TO DIFFERENT SOWING DATES OF NORTHEN IRAQ

This study was conducted at Al-Rasheedia Research Station 5 Km North of Mosul city in plastic pot and placed under natural conditions and watered for the two consecutive growing seasons 2008/2009 and 2009/2010 to study the effect of five sowing dates (1st November. 15th November. 1st December. 15th December. 1st January) on two species of Atriplex; Atriplex halimus and Atriplex lentiformis. The data was analyzed as a factorial experiment in a completely Randomized Design (CRD) with six replicates. Results showed significantly superiority of the first date of sowing 1st November on other dates. Height of plant. root depth and root diameter for the two growing seasons 2008/2009 and 2009/2010. Also on the dry weight of leaves. stems. roots and plant for the two growing seasons. High values were recorded under the first date of sowing 1st November but the low values were recorded under the last date of sowing 1st January for all characters. Also. the results showed significantly superiority of Atriplex halimus on Atriplex lentiformis for all characters under study. There was a significant interaction between the two growing seasons in height of plant. root depth. root diameter and plant dry weight

Treatment impacts on temporal microbial community dynamics during phytostabilization of acid-generating mine tailings in semiarid regions

Direct revegetation, or phytostabilization, is a containment strategy for contaminant metals associated with mine tailings in semiarid regions. The weathering of sulfide ore-derived tailings frequently drives acidification that inhibits plant establishment resulting in materials prone to wind and water dispersal. The specific objective of this study was to associate pyritic mine waste acidification, characterized through pore-water chemistry analysis, with dynamic changes in microbial community diversity and phylogenetic composition, and to evaluate the influence of different treatment strategies on the control of acidification dynamics. Samples were collected from a highly instrumented one-year mesocosm study that included the following treatments: 1) unamended tailings control; 2) tailings amended with 15% compost; and 3) the 15% compost-amended tailings planted with Atriplex lentiformis. Tailings samples were collected at 0, 3, 6 and 12months and pore water chemistry was monitored as an indicator of acidification and weathering processes. Results confirmed that the acidification process for pyritic mine tailings is associated with a temporal progression of bacterial and archaeal phylotypes from pH sensitive Thiobacillus and Thiomonas to communities dominated by Leptospirillum and Ferroplasma. Pore-water chemistry indicated that weathering rates were highest when Leptospirillum was most abundant. The planted treatment was most successful in disrupting the successional evolution of the Fe/S-oxidizing community. Plant establishment stimulated growth of plant-growth-promoting heterotrophic phylotypes and controlled the proliferation of lithoautotrophic Fe/S-oxidizers. The results suggest the potential for eco-engineering a microbial inoculum to stimulate plant establishment and inhibit proliferation of the most efficient Fe/S-oxidizing phylotypes.

Phytoextraction mechanism of Cd by Atriplex lentiformis using some mobilizing agents

Little information is available about the Cd-phytoextraction mechanism by quail bush [Atriplex lentiformis (Torr.) S. Wats]. A pot experiment was conducted using a Cd-polluted soil (50mgkg−1) to explore mechanism of Cd-phytoextraction by quail bush as well as the role of EDTA and vinasse as mobilizing agents. EDTA was applied at a rate of 0, 1, 2, and 3mmolkg−1, while vinasse was applied at a rate of 0, 4, 8, and 16mlkg−1. EDTA had negative effects on the physiochemical properties of the soil. In contrast of EDAT, vinasse caused a remarkable betterment in soil conditions where it increased the soil structure and porosity by 35 and 48% and increased the soil acidity by 8.3%. Growth of roots and shoots reduced by 29 and 33%, respectively; when EDTA was applied at a rate of 3mmolkg−1, on the other hand the application of 16ml of vinasse kg−1 increased the roots and shoots growth by 20 and 21%, respectively. The highest rate of vinasse induced a 31% increase in chlorophyll content but 3mmol of EDTA caused a great negative stress in plant growth and induced a 78% increase in proline content. EDTA and vinasse enhanced the transfer of Cd from soil to roots and from roots to shoots. Quail bush amended with vinasse at a rate of 16mlkg−1 was able to remove 8.34% of the total soil Cd during a 100days, while that amended with 3mmol of EDTA was able to remove 5.51%. EDTA was more effective in increasing Cd availability and uptake, but sugarcane vinasse was more effective in enhancing the Cd-phytoextraction. Based on the obtained results, using sugarcane vinasse to enhance Cd-phytoextraction by quail bush is an effective plan to remediate Cd-contaminated soils.