1,721,037 research outputs found
Effect of aluminium exposure on the release of organic acids and genistein from the roots of Lupinus albus L. plants
No full textAluminum (Al) toxicity is one of the main factors limiting crop productivity in strongly acidic soils. Plant tolerance to Al toxicity has been widely studied even if the mechanisms involved in the plant response are yet not fully elucidated. White lupin is well known to release organic acids and flavonoids under nutrient deficiency, while less is known about its response to elevated Al concentrations. The aim of this work was therefore to shed light to the adaptive response of white lupin to Al toxicity, analysing the root exudate pattern. A pH buffer (MES) or inhibitor compounds were used in order to further investigate the mechanisms adopted by white lupin to release root exudates as response to Al toxicity. The results showed that not only organic acids but also phenolic compounds are involved in the response to elevated concentrations of Al together with the alkalinisation of the growth medium
Influence of different trap solutions on the determination of root exudates in Lupinus albus L
No full textWhite lupin is very often used as a model plant for root exudation studies due to its capability to release huge amounts of organic acids and flavonoids. The complex nature of these organic compounds makes not only their analytical determination difficult but also their extraction from soil samples. For these reasons simplified approaches, as hydroponic-based systems are widely used to study the root exudation. Therefore, the composition of a trap solution is crucial to limit artefacts causing over/underestimation of exudation rates and/or a biased molecular composition of the collected compounds. The present study was aimed at assessing the influence of different trap solutions and collection times on the quali- and quantitative root exudation pattern of white lupin (Lupinus albus L.) grown under phosphorus (P) and iron (Fe) deficiency. Our results suggest that, in works aimed at studying root exudation processes, water is the most effective trap solution to collect the exudates like organic acids and flavonoids, especially in short time (e.g. 2 h). For longer times, low concentrations of Ca could be helpful to limit osmotic stress and possible passive leakage and/or diffusion. The use of bacteriostatic compounds as NaN3 and Micropur bias the results, due to interferences either with the metabolism or inhibition of the exudation processes, especially in the case of flavonoids such as quercetin. Also, the use of a pH buffer solution like 2-(N-morpholino)ethanesulfonic acid (MES) should be avoided for its undesired interferences with the release
Nitrate removal from polluted water by using a vegetated floating system
No full textNitrate (NO3−) water pollution is one of the most prevailing and relevant ecological issues. For instance, the wide
presence of this pollutant in the environment is dramatically altering the quality of superficial and underground
waters. Therefore,we set up a floating bed vegetatedwith a terrestrial herbaceous species (Italian ryegrass) with
the aim to remediate hydroponic solutions polluted with NO3−.
The floating bed allowed the plants to growand achieve an adequate development. Ryegrasswas not affected by
the treatments. On the contrary, plant biomass production and total nitrogen content (N-K) increased proportionally
to the amount of NO3− applied. Regarding to the water cleaning experiments, the vegetated floating
beds permitted to remove almost completely all the NO3− added from the hydroponic solutions with an initial
concentration of 50, 100 and 150 mg L−1. Furthermore, the calculation of the bioconcentration factor (BCF) indicated
this species as successfully applicable for the remediation of solutions polluted by NO3−. In conclusion, the
results highlight that the combination of ryegrass and the floating bed system resulted to be effective in the remediation
of aqueous solutions polluted by NO3−
Effect of three safeners on sulfur assimilation and iron deficiency response in barley (Hordeum vulgare) plants
No full textBACKGROUND: Safeners are agrochemicals used in agriculture to protect crops from herbicide injuries. They act by stimulating herbicide metabolism. As graminaceous plants, to cope with iron (Fe) deficiency, activate sulfur (S) metabolism and release huge amounts of Fe-chelating compounds, or phytosiderophores (PSs), we investigated, in barley plants (Hordeum vulgare, L.) grown in Fe deficiency, the effects of three safeners on two enzymes of S assimilation, cysteine (Cys) and glutathione (GSH), and PS release. Finally, we monitored the root Fe content in plants treated with the most effective safener. RESULTS: Generally, all the safeners activated S metabolism and increased Cys and GSH contents. In addition, the safened plants excreted higher levels of PSs. Given that mefenpyr-diethyl (Mef) was the most effective in causing these effects, we assessed the Fe concentration inMef-treated barley and found higher Fe levels than those in untreated plants.
CONCLUSION: The three safeners, in different ways but specifically, activated S reductive metabolism and regulated Cys and GSH contents, PS release rate and Fe content (Mef-treated barley). The results of this research provide new indications of the biochemical and physiological mechanisms involved in the safening action
The interaction between iron nutrition, plant species and soil type shapes the rhizosphere microbiome
No full textPlant-associated microorganisms can stimulate plants growth and influence both crops yield and quality by nutrient mobilization and transport. Therefore, rhizosphere microbiome appears to be one of the key determinants of plant health and productivity. The roots of plants have the ability to influence its surrounding microbiology, the rhizosphere microbiome, through the creation of specific chemical niches in the soil mediated by the release of phytochemicals (i.e. root exudates) that depends on several factors, such as plants genotype, soil properties, plant nutritional status, climatic conditions.In the present research, two different crop species, namely barley and tomato, characterized by different strategies for Fe acquisition, have been grown in the RHIZOtest system using either complete or Fe-free nutrient solution to induce Fe starvation. Afterward, plants were cultivated for 6 days on two different calcareous soils. Total DNA was extracted from rhizosphere and bulk soil and 454 pyrosequencing technology was applied to V1-V3 16S rRNA gene region. Approximately 5000 sequences were obtained for each sample.The analysis of the bacterial population confirmed that the two bulk soils showed a different microbial community. The presence of the two plant species, as well as the nutritional status (Fe-deficiency and Fe-sufficiency), could promote a differentiation of the rhizosphere microbiome, as highlighted by non-metric multidimensional scaling (NMDS) analysis. Alphaproteobacteria, Actinobacteria, Chloracidobacteria, Thermoleophilia, Betaproteobacteria, Saprospirae, Gemmatimonadetes, Gammaproteobacteria, Acidobacteria were the most represented classes in all the samples analyzed even though their relative abundance changed as a function of the soil, plant species and nutritional status. To our knowledge, this research demonstrate for the first time that different plants species with a diverse nutritional status can promote the development of a peculiar rhizosphere microbiome, depending on the growth substrate
Interazione pianta‐microrganismo‐suolo nel processo di acquisizione del Fe da parte di piante di cetriolo allevate in Fe‐carenza
No full textCharacterization of plant growth promoting traits of bacterial isolates from the rhizosphere of barley (Hordeum vulgare L.) and tomato (solanum lycopersicon L.) grown under Fe sufficiency and deficiency.
No full textPlant Growth Promoting Bacteria (PGPB) are considered a promising approach to replace the conventional agricultural
practices, since they have been shown to affect plant nutrient-acquisition processes by influencing nutrient availability
in the rhizosphere and/or those biochemical processes determining the uptake at root level of nitrogen (N), phosphorus
(P), and iron (Fe), that represent the major constraints for crop productivity worldwide. We have isolated novel bacterial
strains from the rhizosphere of barley (Hordeum vulgare L.) and tomato (Solanum lycopersicon L.) plants, previously
grown in hydroponic solution (either Fe deficient or Fe sufficient) and subsequently transferred onto an agricultural calcareous soil. PGPB have been identified by molecular tools and characterized for their capacity to produce siderophores
and indole-3-acetic acid (IAA), and to solubilize phosphate. Selected bacterial isolates, showing contemporarily high levels of the three activities investigated, were finally tested for their capacity to induce Fe reduction in cucumber roots two
isolates, from barley and tomato plants under Fe deficiency, significantly increased the root Fe-chelate reductase activity;
interestingly, another isolate enhanced the reduction of Fe-chelate reductase activity in cucumber plant roots, although
grown under Fe sufficiency
Does Fe accumulation in durum wheat seeds benefit from improved whole-plant sulfur nutrition?
No full textSulphur (S) and iron (Fe) are an essential macro- and micronutrients for plant growth and development. A balanced supply of S and Fe for plants is of major importance since it has been demonstrated that plant capability to take up and accumulate Fe is strongly dependent on S availability in the growth medium and vice versa. In fact, that Fe deficiency adaptation requires the adjustment of S uptake and assimilation rate. Furthermore, it has been demonstrated that providing S above adequate concentrations may result in the improvement of Fe use efficiency in wheat plants and this S nutritional effect seems to be especially advantageous for plants grown under severe Fe limitation.
Aim of this study was to evaluate whether and to what extent the changes in S nutrition affect Fe accumulation into grains and whether grain Fe concentrations are significantly correlated with the concentration of Fe in the vegetative tissue.
This approach might represent an important tool to realize the improvement of the nutritional value of food crops by increasing Fe content (agronomic biofortification) through soil and crop management strategies which allow to may prevent Fe deficiency in crops without additional input of Fe fertilizers.
Durum wheat plants were grown on sand/perlite mixture with sufficient (1.2 mM) and high (2.5 mM) S supplies and with 10 or 80 M Fe-EDTA during the life cycle.
In particular, we will discuss the effect of S supply on plant growth parameters (fresh and dry weight and chlorophyll content) and on total S accumulation rate at both leaf and seed level. In addition, the relative changes of the leaf and seed ionome induced by different nutritional conditions were evaluated by using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Finally, whole seeds and seed sections were subjected toinvestigated with micro-focused X-ray fluorescence (XRF) imaging to clarify the elemental distribution maps.of several elements, including S and Fe. Significant differences in the concentration and distribution of a number of elements could be observed according to the different treatments
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