11 research outputs found
Interference of Heavy Metal Toxicity with Auxin Physiology
No full textAuxins are important phytohormones involved in the coordination of plant growth and defence. In this chapter, we summarize auxin functions in plant biology and identify interactions with heavy metal toxicity. Cadmium induces the formation of reactive oxygen species, which in turn activate auxin oxidases. Auxin oxidases lead to an increased degradation of auxin and thereby are likely to decrease the activities of many genes involved in growth processes. Evidence supporting this hypothetic signalling cascade from heavy metals to eventual growth reductions comes from auxin feeding experiments that ameliorate Cd toxicity, positive effects of auxin producing endophytes on Cd tolerance and by monitoring endogenous auxin physiology with auxin reporter lines of Arabidopsis thaliana and Populus × canescens. Available data for essential micronutrients suggest that they interact with auxin physiology in a manner similar to Cd when present in excess
Isoprene emission-free poplars - a chance to reduce the impact from poplar plantations on the atmosphere
No full text• Depending on the atmospheric composition, isoprene emissions from plants can have a severe impact on air quality and regional climate. For the plant itself, isoprene can enhance stress tolerance and also interfere with the attraction of herbivores and parasitoids. • Here, we tested the growth performance and fitness of Populus × canescens in which isoprene emission had been knocked down by RNA interference technology (PcISPS-RNAi plants) for two growing seasons under outdoor conditions. • Neither the growth nor biomass yield of the PcISPS-RNAi poplars was impaired, and they were even temporarily enhanced compared with control poplars. Modelling of the annual carbon balances revealed a reduced carbon loss of 2.2% of the total gross primary production by the absence of isoprene emission, and a 6.9% enhanced net growth of PcISPS-RNAi poplars. However, the knock down in isoprene emission resulted in reduced susceptibility to fungal infection, whereas the attractiveness for herbivores was enhanced. • The present study promises potential for the use of non- or low-isoprene-emitting poplars for more sustainable and environmentally friendly biomass production, as reducing isoprene emission will presumably have positive effects on regional climate and air quality
Morpho-Physiological and Proteomic Analyses of <i>Eucalyptus camaldulensis</i> as a Bioremediator in Copper-Polluted Soil in Saudi Arabia
No full textThe present investigation aimed to assess the impact of copper (Cu) stress on the physiological and proteomic behavior of Eucalyptus camaldulensis. E. camaldulensis is likely a potential phytoremediator in areas vulnerable to Cu contamination, such as the industrial areas of Riyadh. To realize this objective, young seedlings of E. camaldulensis were potted in an open area with soil comprised of clay and sand. Different doses of Cu (30, 50, and 100 µM) were applied to the plants as CuSO4·5H2O for 6 weeks. Plant growth was monitored during the Cu exposure period, and morphological and physiological indicators were measured once a week to determine the growth rates. A proteomics study was also conducted to find out the influence of Cu stress on proteins. Our results showed that growth was negatively affected by Cu treatment, particularly at the highest concentrations. Moreover, using a proteomic analysis showed 26 targets involved in protein expression. Elevated levels of Cu increased the expression of 11 proteins and decreased the expression of 15 proteins. Changes were detected in proteins involved in photosynthesis, translation, transcription, metabolism, and antioxidant enzymes. Our findings provided insights into the molecular mechanisms related to Cu stress, in addition to its influence on the morphological and physiological attributes of E. camaldulensis seedlings. This investigation aimed to characterize the mechanism behind the impact of Cu stress on the plant
A Comparative Analysis of the Equity Outcomes in Three Sugarcane–Ethanol Systems
No full textThis article identifies equity outcomes associated with three biofuel systems in Brazil, Ethiopia, and Guatemala. Acknowledging that winners and losers are socially and politically generated, the article identifies some of the factors behind the distribution of winners and losers along different stages of three sugarcane–ethanol supply chains. Analyzing the outcomes for equity within each case study reveals an uneven distribution that, we argue, is related to the procedure and structure of the given sugarcane–ethanol system, and the recognition of the impacts on different actors within those structures. Increasing equity in sugarcane–ethanol systems will require greater openness in decision-making processes, in order that multiple voices are taken into account in the promotion, production, and consumption of biofuels—particularly those of smaller and less powerful actors
Pollution Indexing and Health Risk Assessment of Heavy-Metals-Laden Indoor and Outdoor Dust in Elementary School Environments in Riyadh, Saudi Arabia
No full textThe prevalence of potentially toxic heavy metals (HMs)-bearing dust in the environment is posing serious health risks to humans. Therefore, the occurrence of HMs in indoor and outdoor dust samples of elementary school’s environment in Riyadh, Saudi Arabia, were reported, and associated potential human health risks were estimated in this study. Dust samples were collected from outdoor and indoor environments from eighteen elementary schools using a soft plastic brush. The mean concentrations of Cd, Co, Cu, Ni, Pb, and Zn in collected indoor dust samples were much higher (0.08, 3.45, 59.20, 15.20, 4.99, and 94.10 mg kg−1, respectively) than that of outdoor dust samples (0.07, 3.07, 42.20, 13.60, 4.57, and 62.40 mg kg−1, respectively), due to fans operation, opened windows, and resuspension of dust by children’s activities. The values of estimated enrichment factor revealed that both the outdoor and indoor dusts were moderately contaminated with Zn and Cu, while highly contaminated with Cd and Pb. However, the estimated potential ecological risks associated with HMs were lower. Health risks (non-carcinogenic and carcinogenic) calculations exhibited no potential risks of HMs in the schools’ dust toward children. However, health risks for children were determined in the following order: up to 6 years > 6–12 years > adults. Therefore, assessing the potential health risks posed by HM-contaminated dust in school environments is necessary to avoid any possible children’s health concerns
<i>Lepidium sativum</i> Sprouts Grown under Elevated CO<sub>2</sub> Hyperaccumulate Glucosinolates and Antioxidants and Exhibit Enhanced Biological and Reduced Antinutritional Properties
No full textThe nutritional and health-promoting properties of plants are largely determined by their tissue chemistry. Tuning growth conditions could affect the accumulation of phytochemicals and, therefore, enhance the biological activities. Herein, the impact of elevated CO2 (eCO2; 620 µmol CO2 mol−1 air) on growth and chemical composition of sprouts of three Lepidium sativum cultivars (Haraz, Khider and Rajab) was investigated. Changes in the sprout actions against some human chronic diseases were evaluated. eCO2 induced biomass accumulation (1.46-, 1.47- and 2-fold in Haraz, Khider and Rajab, respectively) and pigment accumulation and reduced the level of antinutrients in L. sativum cultivars. Compared to the control, eCO2 induced total glucosinolate accumulation (0.40-, 0.90- and 1.29-fold in Khider, Haraz and Rajab, respectively), possibly through increased amino acid production, and their hydrolysis by myrosinase. In line with increased polyphenol production, improved phenylalanine ammonia lyase activity was observed. The antioxidant, anti-inflammatory, hypocholesterolemic, antibacterial and anticancer activities of the produced sprouts were significantly improved by sprouting and eCO2 exposure. PCA indicated that the cultivars showed interspecific responses. Thus, the present study confirms the synergistic effect of sprouting with eCO2 exposure as a promising approach to produce more bioactive L. sativum sprouts
Food Aid and the WTO: Can New Rules Be Effective?
No full textA new Agreement on Agriculture from the Doha Development Agenda negotiations is certain to contain binding rules on food aid shipments. Negotiating parties are concerned that food aid has been used as a form of export competition policy, and they seek the use of coercive WTO legislation to prevent the disposal of surplus agricultural commodities as food aid. Current Uruguay Round food aid guidelines are contrasted with the most recent Doha Development Agenda proposals, and the prospective effectiveness of new rules is assessed. Food aid rules will be difficult to enforce within the WTO’s Dispute Settlement Understanding. Also, exogenous policy changes in donor countries are reducing the relevance of rules that target food aid as a means of surplus disposal. The future of international food aid governance in the event of a Doha Round collapse is also discussed.agricultural trade, development economics, export competition, food aid, WTO, Food Security and Poverty, International Relations/Trade, O13, O19, Q17, F13,
Islamic finance : the experience of the Sudanese Islamic Bank in partnership (musharakah) financing as a tool for rural development among small farmers in Sudan.
No full textThe regional economic impacts of biofuels: A review of multisectoral modelling techniques and evaluation of applications
No full textThe regional economic impact of biofuel production depends upon a number of interrelated factors: the specific biofuels feedstock and production technology employed; the sector’s embeddedness to the rest of the economy, through its demand for local resources; the extent to which new activity is created. These issues can be analysed using multisectoral economic models. Some studies have used (fixed price) Input-Output (IO) and Social Accounting Matrix (SAM) modelling frameworks, whilst a nascent Computable General Equilibrium (CGE) literature has also begun to examine the regional (and national) impact of biofuel development. This paper reviews, compares and evaluates these approaches for modelling the regional economic impacts of biofuels.biofuels; economic modelling; input-output; social accounting matrix; computable general equilibrium.
