Sorghum Bicolor Plants Research Articles

The effect of different levels of leachate on phytoremediation of pyrene-contaminated soil and simultaneous extraction of lead and cadmium

Pyrene is one of the 16 group combinations of polyaromatic hydrocarbons, which are known as primary pollutants in the U.S. Environmental Protection Agency (USEPA) list. This study aimed to investigate the cross effect of different levels of landfill leachate on phytoremediation of pyrene-contaminated soil using the sorghum bicolor plant. The study parameters included the presence or absence of the plant, different concentrations of pyrene (150, 300, 500, 750, and 1000 mg kg−1), time (30, 60, and 90 days), and different levels of irrigation with leachate (0, 30, 50, 70, and 100%). Soil pyrene was measured every 30 days, and heavy metals (lead and cadmium) added to the soil by irrigation with leachate were measured in the soil and the plant at the end of 90 days. According to the results, pyrene removal efficiency after 90 days was 96% in irrigation treatments with 30% leachate in the presence of the plant and 67% in irrigation treatments with tap water in the presence of the plant. In addition, 95% of lead and 49% of cadmium added to the soil by irrigation with 30% leachate were extracted from the soil by the sorghum bicolor. According to the results, by increasing nutrients and number of soil bacteria during the cross treatment, landfill leachate increased the pyrene removal efficiency significantly during phytoremediation (p < 0.006) and the sorghum bicolor plant extracted the lead and cadmium of the leachate. In non-planting treatments, although adding high levels of leachate to the soil significantly improved the pyrene removal, it caused the levels of heavy metals, such as lead and cadmium, to exceed the allowable limit (p < 0.001).

Effect of salt tolerance on biomass production in a large population of sorghum accessions.

Salinity causes major reductions in cultivated land area, crop productivity, and crop quality, and salt-tolerant crops have been required to sustain agriculture in salinized areas. The annual C4 crop plant Sorghum bicolor (L.) Moench is salt tolerant, with large variation among accessions. Sorghum’s salt tolerance is often evaluated during early growth, but such evaluations are weakly related to overall performance. Here, we evaluated salt tolerance of 415 sorghum accessions grown in saline soil (0, 50, 100, and 150 mM NaCl) for 3 months. Some accessions produced up to 400 g per plant of biomass and showed no growth inhibition at 50 mM NaCl. Our analysis indicated that the genetic factors that affected biomass production under 100 mM salt stress were more different from those without salt stress, comparing to the differences between those under 50 mM and 100 mM salt stress. A genome-wide association study for salt tolerance identified two single-nucleotide polymorphisms (SNPs) that were significantly associated with biomass production, only at 50 mM NaCl. Additionally, two SNPs were significantly associated with salt tolerance index as an indicator for growth response of each accession to salt stress. Our results offer candidate genetic resources and SNP markers for breeding salt-tolerant sorghum.

Spectroscopic Discrimination of Sorghum Silica Phytoliths.

Grasses accumulate silicon in the form of silicic acid, which is precipitated as amorphous silica in microscopic particles termed phytoliths. These particles comprise a variety of morphologies according to the cell type in which the silica was deposited. Despite the evident morphological differences, phytolith chemistry has mostly been analysed in bulk samples, neglecting differences between the varied types formed in the same species. In this work, we extracted leaf phytoliths from mature plants of Sorghum bicolor (L.) Moench. Using solid state NMR and thermogravimetric analysis, we show that the extraction methods alter greatly the silica molecular structure, its condensation degree and the trapped organic matter. Measurements of individual phytoliths by Raman and synchrotron FTIR microspectroscopies in combination with multivariate analysis separated bilobate silica cells from prickles and long cells, based on the silica molecular structures and the fraction and composition of occluded organic matter. The variations in structure and composition of sorghum phytoliths suggest that the biological pathways leading to silica deposition vary between these cell types.

Modelling and Optimizing Pyrene Removal from the Soil by Phytoremediation using Response Surface Methodology, Artificial Neural Networks, and Genetic Algorithm

This study aimed to model and optimize pyrene removal from the soil contaminated by sorghum bicolor plant using Response Surface Methodology (RSM) and Artificial Neural Network (ANN) with Genetic Algorithm (GA) approach. Here, the effects of indole acetic acid (IAA) and pseudomonas aeruginosa bacteria on increasing pyrene removal efficiency by phytoremediation process was studied. The experimental design was done using the Box-Behnken Design (BBD) technique. In the RSM model, the non-linear second-order model was in good agreement with the laboratory results. A two-layer Feed-Forward Back-Propagation Neural Network (FFBPNN) model was designed. Various training algorithms were evaluated and the Levenberg Marquardt (LM) algorithm was selected as the best one. Existence of eight neurons in the hidden layer leads to the highest R and lowest MSE and MAE. The results of the GA determined the optimum performance conditions. The results showed that using indole acetic acid and pseudomonas bacteria increased the efficiency of the sorghum plant in removing pyrene from the soil. The comparison obviously indicated that the prediction capability of the ANN model was much better than that of the RSM model.

Modeling and Cr(VI) ion uptake kinetics of Sorghum bicolor plant assisted by plant growth-promoting Pannonibacter phragmetitus: an ecofriendly approach.

The research work focuses on the application of Cr(VI)-resistant plant growth-promoting bacteria Pannonibacter phragmetitus for enhancing Cr(VI) uptake by Sorghum bicolor. Significant increase in plant shoot and root characters was found when assisted by P. phragmetitus. The obtained strain showed 700 mg/L of chromium reduction at 24-h incubation. Indole-3 acetic acid (IAA) production by the bacterial strain was found to be 86.45 μg/mL. Pannonibacter phragmetitus solubilized tricalcium phosphate showing maximum solubilizing activity of PSI = 3.31. The qmax of P. phragmetitus was high in the wavelength of 600 nm. Langmuir isotherm best described the Cr(VI) ion uptake by the plant. The RL values reliably reduced with expanding Cr(VI) ion concentration from 25 to 150 mg/L. The outcomes of kinetic studies showed that compared with pseudo first-order, pseudo second-order kinetics better describes the plant Cr(VI) uptake rate. Elovich model describes the increased rates for attaining equilibrium. The equilibrium parameter values for different Cr(VI) ion concentrations range between 0 and 1 which describes the favorable condition for plant metal uptake at different concentrations. Graphical abstract.

Pengaruh Sumber dan Dosis Bahan Organik terhadap Perubahan sifat Kimia Tanah, Pertumbuhan dan Hasil Tanaman Sorgum (Sorghum bicolor L.Moench) var. KD4 di Lahan Kering Jatikerto, Malang

Suminarti et al, 2018. Effect of Source and Dosage of Organic Materials on Changes in Soil Chemical Properties, Growth and Yield of Sorghum Plants (Sorghum bicolor L.Moench) var. KD4 in Dry Land Jatikerto, Malang. JLSO 7(2): Agricultural extensification is the right step to anticipate conditions of food insecurity. This refers to two reasons, namely (1) proliferation of land conversion activities, and (2) sorghum is a carbohydrate-producing plant that is quite tolerant when planted on dry land. The objective of this study was to obtain information about the sources and doses of organic matter that are appropriate to changes in soil chemical properties, growth and yield of sorghum plants, and has been carried out in the dry land of Jatikerto, Malang. A split plot designs with three replications were used in this study, sources of organic material (blothong, UB compost and cow dung) as the main plot, and doses of organic matter (125%, 100% and 75%) as a subplot. Soil analysis was carried out 3 times, i.e. before planting, after application of organic matter and at harvest. The agronomic observations were carried out destructively at 80 days after planting (DAP) including the components of growth (root dry weight, leaf area, and total dry weight of the plant) and harvest at the age of 90 DAP.F test at 5% level was used to test the effect of treatment, while the difference between treatments was based on LSD level of 5%.The results showed that there was a significant interaction between the source and dosage of organic matter on the leaf area and total dry weight, the highest yield was obtained in blothong at various doses. Higher yields of seeds per hectare were also found in blotong: 1.76 tons ha-1, and 1.73 tons ha-1 on 125% doses of organic matter. Blotong application is able to provide elements of N, P and K soil respectively 18.3%, 85.68% and 8.42% for plant.

Estimation of Sulfentrazone Leaching in Isolated Application and in Mixture with Glyphosate

ABSTRACT: As an alternative to control of resistant biotypes, farmers have resorted to the use of herbicides that have residual soil activity and good pre-emergence action. One of the most used mixtures in Brazil is that of sulfentrazone + glyphosate. When a herbicide has a pre-emergence action, small leaching of its molecules is necessary for its superficial incorporation into the soil, where most of the weed seeds are found. However, if excessive leaching occurs, the herbicide may have reduced efficiency in controlling weed, increasing the risks of groundwater contamination. In this study, sulfentrazone leaching was evaluated in columns with soil, in isolated applications and in mixture with formulations of glyphosate (Roundup Ready®, Roundup Ultra® and Zapp Qi®). For this, the columns were filled with samples of Red-Yellow Latosol, collected in the 0-20 cm depth layer. After moistening the columns to near field capacity, the herbicides were applied to the top and, 24 hours later, a 60 mm rainfall was simulated. After 72 hours, the columns were sectioned in 5 cm segments, collecting the soil from each segment. In these samples, indicator plants (Sorghum bicolor) were cultivated for the presence of the herbicide. It is concluded that, in general, glyphosate does not alter the leaching potential of sulfentrazone in the Red-Yellow Latosol. However, mixtures with Roundup Ready® and Zapp Qi® reduce the sorptive forces of sulfentrazone to soil colloids. Therefore, in some types of soil, herbicide desorption may occur with greater intensity, making its availability in the soil solution more difficult. This may result in better control of plants and/or intoxication of sensitive crops.

Effects of two contrasted arbuscular mycorrhizal fungal isolates on nutrient uptake by Sorghum bicolor under drought.

Drought is a limiting factor for crop production, especially in arid and semi-arid climates. In this study, Sorghum bicolor plants were inoculated, or not, with Rhizophagus irregularis, an arbuscular mycorrhizal (AM) strain typical for temperate climates, or Rhizophagus arabicus, a strain endemic to hyper-arid ecosystems. Plants were grown under well-watered or drought conditions in compartmented microcosms. Transpiration rates, plant growth, and nutrient uptake (using 15N as a tracer) were determined to assess the impact of drought stress on sorghum plants in AM symbiosis. Although AM colonization did not affect the bulk biomass of host plants, R. arabicus improved their transpiration efficiency and drought tolerance more than R. irregularis. Moreover, R. arabicus was able to extract more 15N from the soil under both water regimes, and AM-driven enhancement of the nitrogen and phosphorus content of sorghum, especially when water was limiting, was greater for R. arabicus-inoculated plants than for R. irregularis-inoculated plants. Our work demonstrates close links between AM hyphal phosphorus and nitrogen transport and uptake by AM plants for both AM fungal species. It also underscores that, under the drought stress conditions we applied, R. arabicus transfers significantly more nitrogen to sorghum than R. irregularis.

Direct observation of multiple conformational states in Cytochrome P450 oxidoreductase and their modulation by membrane environment and ionic strength

Cytochrome P450 oxidoreductase (POR) is the primary electron donor in eukaryotic cytochrome P450 (CYP) containing systems. A wealth of ensemble biophysical studies of Cytochrome P450 oxidoreductase (POR) has reported a binary model of the conformational equilibrium directing its catalytic efficiency and biomolecular recognition. In this study, full length POR from the crop plant Sorghum bicolor was site-specifically labeled with Cy3 (donor) and Cy5 (acceptor) fluorophores and reconstituted in nanodiscs. Our single molecule fluorescence resonance energy transfer (smFRET) burst analyses of POR allowed the direct observation and quantification of at least three dominant conformational sub-populations, their distribution and occupancies. Moreover, the state occupancies were remodeled significantly by ionic strength and the nature of reconstitution environment, i.e. phospholipid bilayers (nanodiscs) composed of different lipid head group charges vs. detergent micelles. The existence of conformational heterogeneity in POR may mediate selective activation of multiple downstream electron acceptors and association in complexes in the ER membrane.

Allelopathic activity and chemical constituents of extracts from roots of Euphorbia heterophylla L

Euphorbia heterophylla L. is regarded as a major weed worldwide. Its high aggressiveness in agricultural environment prompted us to investigate the allelopatic activity and chemical constitution of extracts from roots of this plant. Hexane extract showed low phytotoxic activity. Methanol extract at 2.0 mg mL−1 inhibited 100% of germination, root and shoot growth of the indicator plants Sorghum bicolor and Lactuca sativa. β-sitosterol, stigmasterol, and esters of lupeol, germanicol, taraxasterol, pseudotaraxasterol, α-amyrin and β-amyrin were isolated from the hexane extract and their structures elucidated on the basis of MS and 1H, 13C and DEPT-135 NMR data. GC-MS analysis of the derivatized methanol extract allowed for identifying a series of allelopathic organic acids potentially involved in allelopathic interactions of E. heterophylla. This is the first study on the allelopathic activity of extracts and identification of metabolites from roots of E. heterophylla.

Excess of soil zinc interferes with uptake of other micro and macro nutrients in Sorghum bicolor (L.) plants

Zinc an essential micronutrient, can be a notorious pollutant when in excess. It can interfere with plant metabolism, physiology and uptake of other mineral nutrients leading to serious effects on plants. A soil experiment was carried out in Sorghum, which is one of the major crop of arid and semi-arid regions of the world and an excellent material for abiotic stress studies. Sorghum plants were raised in pots for 50 days and were treated with various concentration of zinc given as milli molar solution (viz; 1.5, 3.5, 5.5, 7.5, 9.5 mM). In the present experiment soil applied zinc caused a linear increase in the tissue zinc content. The investigation revealed that excess zinc interferes with the absorption and utilization of micro (Fe, Cu and Mn) and macro (Ca and Mg) nutrients. Fe and Mn absorption was hampered at elevated levels. Ca and Mg content decreased with increase in soil applied zinc in the roots and shoots of Sorghum bicolor plants.

A capillary micellar electrokinetic chromatography method for the stereoselective quantitation of bioallethrin in biotic and abiotic samples

A capillary micellar electrokinetic chromatography (MEKC) method was developed enabling the stereoselective separation of the insecticide bioallethrin. The use of sodium deoxycholate bile salt and acetyl-β-cyclodextrin (acetyl-β-CD) made possible the separation of bioallethrin stereoisomers with a high enantioresolution (7.4) in a short analysis time (6.5min). The analytical characteristics of the developed method were evaluated in terms of linearity, accuracy, precision, and limits of detection (LOD) and quantitation (LOQ) showing a good performance for the quantitation of bioallethrin stereoisomers with LODs of 0.2 and 0.3mg/L. The developed method was applied to the stereoselective analysis of a commercial bioallethrin pediculicide formulation and to evaluate the toxicity of bioallethrin stereoisomers on the growth of the unicellular freshwater green alga Pseudokirchneriella subcapitata and on the germination of the higher plant Sorghum bicolor (non-target organisms). The analysis of the commercial pediculicide showed a good agreement between the contents determined for the two stereoisomers and those labelled in the commercial samples. Different toxic responses and biodegradation profiles were found for each stereoisomer in ecotoxicity assays. The mixture of S/R stereoisomers of bioallethrin resulted more toxic than S-bioallethrin for green algae, with EC50 values of 1.10±0.06 for the mixture and of 1.73±0.05mg/L for the pure S-biallethrin (esbiol). Germination of plants seeds was also affected.

Involvement of phosphoenolpyruvate carboxylase and antioxydants enzymes in nitrogen nutrition tolerance in Sorghum bicolor plants

Plants of Sorghum bicolor (C4 species) were grown at different nitrate or ammonium concentrations (0.5, 5, 20 and 50 mM) in order to examine the effect of nitrogen nutrition on growth, phosphoenolpyruvate carboxylase (PEPC) and antioxidant enzymes activities in both roots and leaves of 30-day-old plants. At high NO3− levels (20 and 50 mM) the fresh weight was significantly higher. When the nitrogen source was in ammonium form, the leaf and root mass increased drastically at low concentration 5 mM and significantly at 20 mM, however similar fresh weight was found at high level of ammonium (50 mM). The leaves catalase (CAT), guaiacol peroxidase (POD), glutathione reductase (GR), and glutathione S-transferase (GST) activities and the roots glutathione reductase and glutathione S-transferase activities were significantly higher in the NH4+-fed plants than those grown in the nitrate medium. Activity and proteins levels of phosphoenolpyruvate carboxylase in both leaves and roots of sorghum plants were increased progressively with increasing external nitrogen concentration. This increase was more pronounced at high level of ammonium (50 mM), being 2-fold at 50 mM of NO3− and 3-fold at 50 mM of NH4+. Our results suggested that antioxidant enzymes activities and PEPC play a key role in ammonium detoxification and tolerance in sorghum plants.

Propiconazole and Salicylic acid alleviate effect of drought stress in sorghum (Sorghum bicolor L. Moench) through biochemical and some physiological characters.

In this study, the protective role of propiconazole (PCZ) and salicylic acid (SA) in relation to biochemical content and some physiological parameters were investigated in drought stressed Sorghum bicolor plants. The pot culture experiment was carried out on Botanical garden, Deportment of Botany, Annamalai University. A 30 Days After Sowing (DAS) plants were subjected to 3, 6, and 9 Days Interval Drought (DID) stress and drought with PCZ at 1 mM and drought with SA at 1 mM at 30, 40, and 50 DAS. The plants irrigated regularly in alternate day interval were kept as control. The plant samples were collected on 60, 70, and 80 DAS from all the treatments. The biochemical contents like starch and sucrose, then physiological parameter like Relative Water Content (RWC) and Electrolyte Leakage (EL) were analysed. Under the drought stress reduced starch and RWC was observed then, sucrose and EL content were increased. The drought with growth regulator treated plants starch and RWC was reduced then, sucrose and EL was increased but it was lower than that of control. Together, our findings demonstrate that, PCZ and SA is an efficient growth regulator with diversified roles that contribute to its potential alleviating effect against drought stress.

Fusion of Ferredoxin and Cytochrome P450 Enables Direct Light-Driven Biosynthesis.

Cytochrome P450s (P450s) are key enzymes in the synthesis of bioactive natural products in plants. Efforts to harness these enzymes for in vitro and whole-cell production of natural products have been hampered by difficulties in expressing them heterologously in their active form, and their requirement for NADPH as a source of reducing power. We recently demonstrated targeting and insertion of plant P450s into the photosynthetic membrane and photosynthesis-driven, NADPH-independent P450 catalytic activity mediated by the electron carrier protein ferredoxin. Here, we report the fusion of ferredoxin with P450 CYP79A1 from the model plant Sorghum bicolor, which catalyzes the initial step in the pathway leading to biosynthesis of the cyanogenic glucoside dhurrin. Fusion with ferredoxin allows CYP79A1 to obtain electrons for catalysis by interacting directly with photosystem I. Furthermore, electrons captured by the fused ferredoxin moiety are directed more effectively toward P450 catalytic activity, making the fusion better able to compete with endogenous electron sinks coupled to metabolic pathways. The P450-ferredoxin fusion enzyme obtains reducing power solely from its fused ferredoxin and outperforms unfused CYP79A1 in vivo. This demonstrates greatly enhanced electron transfer from photosystem I to CYP79A1 as a consequence of the fusion. The fusion strategy reported here therefore forms the basis for enhanced partitioning of photosynthetic reducing power toward P450-dependent biosynthesis of important natural products.

Multidisciplinary study of chemical and biological factors related to Pb accumulation in sorghum crops grown in contaminated soils and their toxicological implications

In this study, the content of Pb, the physico-chemical and biological parameters in soils, and the metal transfer to vegetative and reproductive Sorghum bicolor plants were evaluated along with their relationship with the toxicological risk of crop consumption. To carry this out, soil and sorghum samples at different growth stages were collected near to a former battery recycling plant. The results showed that the concentrations of Pb in soils at several sites were above the maximum permissible levels. Metal bioavailability was not directly related to the pH, OM% or EC, while no association between metals and the different genera of fungi was observed. Sorghum crops accumulated Pb mainly in the roots in all of the growth stages, and therefore presented low levels of Pb in aerial parts without toxicological risk due to direct consumption. Taken together, our results revealed that sorghum could be employed as a potential phytostabilizator of lead in soils associated with crop production. However, further studies are necessary to extend these findings.

Plant growth conditions alter phytolith carbon.

Many plants, including grasses and some important human food sources, accumulate, and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM) that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin, and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a “glass wastebasket.” Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins, and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction.

Harnessing Genetic Variation in Leaf Angle to Increase Productivity of Sorghum bicolor.

The efficiency with which a plant intercepts solar radiation is determined primarily by its architecture. Understanding the genetic regulation of plant architecture and how changes in architecture affect performance can be used to improve plant productivity. Leaf inclination angle, the angle at which a leaf emerges with respect to the stem, is a feature of plant architecture that influences how a plant canopy intercepts solar radiation. Here we identify extensive genetic variation for leaf inclination angle in the crop plant Sorghum bicolor, a C4 grass species used for the production of grain, forage, and bioenergy. Multiple genetic loci that regulate leaf inclination angle were identified in recombinant inbred line populations of grain and bioenergy sorghum. Alleles of sorghum dwarf-3, a gene encoding a P-glycoprotein involved in polar auxin transport, are shown to change leaf inclination angle by up to 34° (0.59 rad). The impact of heritable variation in leaf inclination angle on light interception in sorghum canopies was assessed using functional-structural plant models and field experiments. Smaller leaf inclination angles caused solar radiation to penetrate deeper into the canopy, and the resulting redistribution of light is predicted to increase the biomass yield potential of bioenergy sorghum by at least 3%. These results show that sorghum leaf angle is a heritable trait regulated by multiple loci and that genetic variation in leaf angle can be used to modify plant architecture to improve sorghum crop performance.

Mapping of a Cellulose-Deficient Mutant Named dwarf1-1 in Sorghum bicolor to the Green Revolution Gene gibberellin20-oxidase Reveals a Positive Regulatory Association between Gibberellin and Cellulose Biosynthesis.

Here, we show a mechanism for expansion regulation through mutations in the green revolution gene gibberellin20 (GA20)-oxidase and show that GAs control biosynthesis of the plants main structural polymer cellulose. Within a 12,000 mutagenized Sorghum bicolor plant population, we identified a single cellulose-deficient and male gametophyte-dysfunctional mutant named dwarf1-1 (dwf1-1). Through the Sorghum propinquum male/dwf1-1 female F2 population, we mapped dwf1-1 to a frameshift in GA20-oxidase. Assessment of GAs in dwf1-1 revealed ablation of GA. GA ablation was antagonistic to the expression of three specific cellulose synthase genes resulting in cellulose deficiency and growth dwarfism, which were complemented by exogenous bioactive gibberellic acid application. Using quantitative polymerase chain reaction, we found that GA was positively regulating the expression of a subset of specific cellulose synthase genes. To cross reference data from our mapped Sorghum sp. allele with another monocotyledonous plant, a series of rice (Oryza sativa) mutants involved in GA biosynthesis and signaling were isolated, and these too displayed cellulose deficit. Taken together, data support a model whereby suppressed expansion in green revolution GA genes involves regulation of cellulose biosynthesis.

Ammonium improves tolerance to salinity stress in Sorghum bicolor plants

Sorghum bicolor plants were grown in five combinations of NO3 −:NH4 + nutrition (100:0, 75:25, 50:50, 25:75 and 0:100) to test the hypothesis that nitrogen nutrition with ammonium (NH4 +) increases tolerance to salinity. Analyses were performed after 10 days of 75 mM NaCl stress. The K+ contents in the shoots and roots were reduced under salinity stress; however, salt-stressed plants from NO3 −:NH4 + treatments of 100:0 and 0:100 showed higher K+ concentrations in the shoots. Under salinity, Na+ accumulation was severely limited in the presence of NH4 + (0:100), which positively influenced K+/Na+ homeostasis. In parallel, NH4 +-fed plants displayed a substantial accumulation of N-rich amino acids (primarily glutamine and asparagine) in both tissues, which might be fundamental for alleviating NH4 + toxicity. These responses were reflected in favorable gas exchange and growth. Whereas the photosynthetic rate (A) of plants treated with 100:0, 75:25, 50:50 and 25:75 ratios were unaltered or reduced under salinity stress, plants treated with a ratio 0:100 showed increases in A; this phenomenon was strongly correlated with the higher instantaneous carboxylation efficiency of Rubisco (A/Ci) and total N content in the shoots. As a result, although the leaf area and shoot and root dry mass from all nitrogen treatments were severely reduced through stress, the NH4 + supply was effective to alleviate the harmful effects of salinity. The results clearly demonstrate that ammonium nutrition is more advantageous for the growth of S. bicolor under salinity than nitrate nutrition. Our findings suggest that improved plant acclimation induced through NH4 + resulted from increased photosynthesis performance, reduced Na+ toxicity effects and major N-compound content.