Concentrations In Seedlings Research Articles

ZmKTF1 promotes salt tolerance by mediating RNA-directed DNA methylation in maize.

The epigenetic process of RNA-directed DNA methylation (RdDM) regulates the expression of genes and transposons. However, little is known about the involvement of RdDM in the response of maize (Zea mays) to salt stress. Here, we isolated a salt-sensitive maize mutant and cloned the underlying gene, which encodes KOW DOMAIN-CONTAINING TRANSCRIPTION FACTOR1 (KTF1), an essential component of the RdDM pathway. Evolutionary analysis identified two homologs of KTF1 (ZmKTF1A and ZmKTF1B) with highly similar expression patterns. Whole-genome bisulfite sequencing revealed that mutations in ZmKTF1 substantially decrease genome-wide CHH (H = A, C, or T) methylation levels. Moreover, our findings suggest that ZmKTF1-mediated DNA methylation regulates the expression of multiple key genes involved in oxidoreductase activity upon exposure to salt, concomitant with increased levels of reactive oxygen species. In addition, insertion-deletion mutations (InDels) in the promoter of ZmKTF1 affect its expression, thereby altering Na+ concentrations in seedlings in a natural maize population. Therefore, ZmKTF1 might represent an untapped epigenetic resource for improving salt tolerance in maize. Overall, our work demonstrates the critical role of ZmKTF1 involved in the RdDM pathway in maize salt tolerance.

Pinecone failure, hydrogel, fertilizer and volume of containers in the production of araucaria seedlings

The objective of this work was the evaluation of initial growth and quality of araucaria seedlings under the influence of alterations to different proprieties of the substrate. Four different experiments were installed, comparing volume of tubes, concentrations of controlled release fertilizer (FLC), proportion of crushed pinecone failures (substrate characteristics were also evaluated) and the effect of hydrogel concentrations in seedlings derived from different mother trees. The evaluations were carried out 10 months after sowing, varying according to the experiment, and were comprised of height, diameter, height/diameter ratio (h/d), survival rate and germination speed index. The seedlings developed inside the larger tubes (280 cm3) averaged higher in height, diameter and h/d ratio. The 6 g L-1 dose of fertilizer generated higher averages for all analyzed variables. The addition of pinecone failure to the substrate improved some physical attributes such as density, total porosity and aeration space, however it worsened the attributes related to water availability in the substrate. As for the growth of seedlings, the addition of pinecone failure did not change the height, diameter and h/d ratio. The use of hydrogel (3 g L-1 and 6 g L-1) generated better results for height. It is recommended the use of 180 cm³ tubes and 6 g L-1 of the contloed release fertilizer. Pinecone can be used in the substrate, as well as hydrogel as a additional resource.

Glucoraphanin Accumulation via Glucoraphanin Synthesis Promotion during Broccoli Germination.

Glucoraphanin is an important glucosinolate which is widely distributed in Brassica vegetables and poses an anticancer effect to humans. Although researchers have paid a lot of attention to the changes in glucoraphanin concentration in seedlings of broccoli over 1-2 weeks, there has been little research focusing on the total whole-sprout glucoraphanin content within broccoli seedlings over 1-5 weeks. However, it is necessary to clarify the changes in total glucoraphanin content during the broccoli sprouting stage as broccoli seedlings are novel plant foods. This research explored glucoraphanin absolute accumulation and the biosynthesis mechanism in broccoli seedlings during a 5-week growth period. The results showed that glucoraphanin accumulation content was higher at week 4 than in the seeds. Moreover, the relative DL-methionine contents increased significantly after 3 weeks. Glucoraphanin synthetic gene expression levels were increased after 3 weeks, but the gene expressions of AOP3 (encoding 2-oxoglutarate-dependent dioxygenases) and MYR (encoding myrosinase) were significantly decreased. Furthermore, the 20 essential DEGs obtained can provide new insight into understanding the developmental regulation of broccoli seedlings. In addition, the results can also provide information on how to obtain higher glucoraphanin contents in broccoli sprouts.

Proline concentrations in seedlings of woody plants change with drought stress duration and are mediated by seed characteristics: a meta-analysis

Proline accumulation represents one of mechanisms used by plants to prevent the adverse consequences of water stress. The effects of increased proline levels in response to drought differ among species. Trees are exposed to the long-term effects of climate change. The reproductive success of species in a specific environment depends on the functional trait of tree seeds. We conducted a meta-analysis to evaluate the effects of drought stress on the proline concentrations in seedling leaf tissues of woody plant species and their relationships to drought duration, seed mass, seed category and coniferous/deciduous classification. Drought duration exhibited a nonlinear effect on proline accumulations. The drought effect on proline accumulations is greater for deciduous than for coniferous species and is higher for orthodox seed species than for recalcitrant. The seedlings of large-seeded species showed greater effect sizes than those of small-seeded species. Our results suggest that there is an optimum level at which proline accumulations under the influence of drought are the highest. A link between seed functional traits, as well as the coniferous/deciduous classification, and proline concentrations in tree seedlings during water stress were determined for the first time. Proline may help to identify high-quality seeds of trees used for reforestation.

Exopolysaccharides from endophytic Glutamicibacter halophytocota KLBMP 5180 functions as bio-stimulants to improve tomato plants growth and salt stress tolerance

Microbial exopolysaccharides (EPSs) can promote plants growth and protect them against various abiotic stresses, but the role of actinobacteria-produced EPSs in plant growth promoting is still less known. Here, we aim to explore the effect of EPSs from an endophyte Glutamicibacter halophytocota KLBMP 5180 on tomato seeds germination and seedlings growth under salt stress. Our study revealed that 2.0 g/L EPSs resulted in increased seed germination rate by 23.5 % and 11.0 %, respectively, under 0 and 200 mM NaCl stress conditions. Further pot experiment demonstrated that EPSs significantly promoted seedlings growth under salt stress, with increased height, root length and fibrous roots number. Plant physiological traits revealed that EPSs increased chlorophyll content, enhanced the activity of antioxidant enzymes, soluble sugar, and K+ concentration in seedlings; malondialdehyde and Na+ contents were reduced. Additionally, auxin, abscisic acid, jasmonic acid, and salicylic acid were accumulated significantly in seedlings after EPSs treatment. Furthermore, we identified 1233 differentially expressed genes, and they were significantly enriched in phytohormone signal transmission, phenylpropanoid biosynthesis, and protein processing in endogenous reticulum pathways, etc. Our results suggest that KLBMP 5180-produced EPSs effectively ameliorated NaCl stress in tomato plants by triggering complex regulation mechanism, and showed application potentiality in agriculture.

Inhibition of Nickel (II) Mobility in Theobroma cacao L. Seedlings Using Zeolite 5A

In search of efficient solutions for the treatment of contaminated soils and in favor of the sustainable development of agriculture, this work aimed at developing an efficient method that helps to directly overcome the contamination by nickel in soils and Theobroma cacao L. seedlings. In this study, the genotypes ICS-39, CCN-51, and TSH-1188, which are high-yielding varieties in South America, were studied. The compound used as an adsorbent was commercial zeolite 5A. The zeolite 5A and soil samples were analyzed by X-ray diffraction, Raman microscopy, chemical analysis, electron microscopy techniques, and atomic absorption spectroscopy. This last technique was used for quantitative determination of Ni concentrations in seedlings. Zeolite 5A presented a high adsorption efficiency (95%) among the studied cacao genotypes, making this material a viable adsorbent and inhibitor agent of Ni. In addition, zeolite 5A was found to be not chemically harmful to the plant morphology (root and height), as demonstrated using statistical analysis. Finally, the Ni mechanism was described based on zeolite 5A physicochemical properties, suggesting that this material has remarkable soil remediation application.

Atmospheric pressure plasma treatment induces abscisic acid production, reduces stomatal aperture and improves seedling growth in Arabidopsis thaliana.

Cold atmospheric pressure plasmas (CAPPs) have been widely used for pre-sowing treatment in agriculture to accelerate seed germination; however, information on their application to pre-transplant seedlings is scarce. The roles of the phytohormone abscisic acid (ABA) on guard cell aperture that control air exchange with the environment were investigated after CAPPs treatment. In this study, Arabidopsis thaliana seedling growth was evaluated under CAPPs treatment at different doses. Besides, the optimal growth stimulation dose was selected to further evaluate changes in ABA, ROS, Ca2+ and stomatal aperture during growth .The expression of most ABA signalling genes were aslo examined to investigate the mechanism. CAPPs treatment for 1 min significantly promoted Arabidopsis seedling growth; the ABA concentration in seedlings increased and peaked 48 h after treatment but was lower than in the control after 96 h. Transcript levels of most ABA signalling genes were markedly enhanced at 48 h, although their transcripts were significantly downregulated after 96 h. CAPPs treatment also reduced stomatal aperture after 24 h and accelerated ROS accumulation in guard cells. The Ca2+ concentration in the treatment group was markedly higher than in the control at 24 and 96 h. The results suggest that CAPPs treatment accelerates ABA accumulation in Arabidopsis at early growth stages and ABA regulates ROS and Ca2+ concentrations to affect stomatal aperture, and both ABA and stoma size are affected in CAPPs stimulation of Arabidopsis seedling growth.

The decoupling between gas exchange and water potential ofCinnamomum camphoraseedlings during drought recovery and its relation to ABA accumulation in leaves

AbstractAimsDrought stress and the degree of drought severity are predicted to rise under highly variable patterns of precipitation due to climate change, while the capacity of trees to cope with drought recovery through physiological and biochemical adjustment remains unclear. We aimed to examine the coupling of physiology and biochemistry in trees during drought and the following recovery.MethodsPotted seedlings of Cinnamomum camphora were grown under well watered conditions prior to the experimental drought stress, which was initiated by withholding water. Seedlings were rewatered following attainment of two drought severities: mild drought (stomatal closure) and moderate drought (ψxylem = −1.5 MPa). We measured leaf-level water potential, gas exchange (photosynthesis and stomatal conductance), abscisic acid (ABA), proline and non-structural carbohydrates (NSCs) concentrations in seedlings of C. camphora during drought and a 4-day recovery.Important FindingsWe found that drought severity largely determined physiological and biochemical responses and affected the rate of recovery. Stomatal closure occurred at the mild drought stress, accompanied with ABA accumulation in leaves and decline in water potential, while leaf proline accumulation and variable NSC were evident at the moderate drought stress. More severe drought stress led to delayed recovery of gas exchange, but it did not have significant effect on water potential recovery. The relationships of water potential and gas exchange differed during drought stress and post-drought recovery. There was tight coupling between water potential and gas exchange during drought, but not during rewatering due to high ABA accumulation in leaves, thereby delaying recovery of stomatal conductance. Our results demonstrate that ABA could be an important factor in delaying the recovery of stomatal conductance following rewatering and after water potential recovery of C. camphora. Furthermore, greater drought severity had significant impacts on the rate of recovery of tree physiology and biochemistry.

Phytotoxicity of iron-based materials in mung bean: Seed germination tests

Environmental applications and potential risks of iron-based materials have attracted increasing attention. However, most previous studies focused on a single material. Comparative research using different iron-based materials under the same experimental conditions is still lacking. Here, six iron-based materials, including micro-sized and nanoscale Fe3O4 (i.e., mFe3O4 and nFe3O4), bulk and bare nanoscale zero-valent iron (i.e., mZVI and B-nZVI), starch-supported nZVI (S-nZVI), and activated carbon-supported nZVI (A-nZVI), were studied to compare their phytotoxicity in mung bean grown in suspensions with doses of 0, 300, 600 and 1000 mg/L. Taking the four toxicology parameters (seed germination rate, germination index, seedling elongation and biomass) together, the iron-based materials except mFe3O4 generally produced no significant phytotoxicity to mung bean even at 1000 mg/L. nFe3O4 and B-nZVI showed no higher phytotoxicity than their micro-sized counterparts (mFe3O4 and mZVI). All the materials resulted in increased Fe concentrations in seedlings particularly in roots, and mZVI and B-nZVI produced more significant effects. However, the Fe in the roots was difficultly translocated to the shoots. Compared to B-nZVI, nFe3O4 had lower bioavailability and bioaccumulation potential. XRD results confirmed that most Fe3O4 and B-nZVI remained unchanged during seedling growth, while support materials accelerated the corrosion and transformation of S-nZVI and A-nZVI. In conclusion, the tested nanoscale iron-based materials generally possess no obvious phytotoxicity within the dose range, but cause excess Fe accumulation in seedlings. Introduction of support materials may reduce such risk, allowing safer applications of these iron-based materials.

Moderate Soil Salinity Alleviates the Impacts of Drought on Growth and Water Status of Plants

Drought and soil salinity are the main environmental stress factors affecting plant growth and development. A certain appropriate concentration of NaCl in the soil has been suggested to show a beneficial effect on halophyte and xerophyte growth, while drought could cause severe damage to plants. Thus, under drought conditions, whether the moderate soil salinity could still stimulate all plant growth and productivity is curious. In this study, three plants with different salt tolerance, including arrowleaf saltbush (Atriplex tr-iangularis Willd.), cotton (Gossypium hirsutum L.) and soybean [Glycine max (Linn.) Merr.], were sown in soils containing different concentrations of NaCl and exposed to drought and non-drought conditions for 30 days. The shoot biomass, water potential, osmotic potential, Na+ and K+ concentrations in seedlings were measured. Both drought and salt stress could inhibit the growth of arrowleaf saltbush, cotton and soybean, but the decreases in plant height and shoot biomass under drought conditions were attenuated with the increase of NaCl concentration. The Na+ concentration in the leaves subjected to combined drought and salt stresses was significantly higher than that in leaves subjected only to drought stress. Meanwhile, the osmotic potential of the leaves was significantly lower in the former than the latter, and the RWC and cell turgor pressure in the leaves were significantly higher in the former than the latter. Our results prove that the appropriate soil salinity could alleviate the detrimental effects of drought stress on the water status and plant growth, no matter they are salt-tolerant or salt-sensitive plants.

Effect of phosphate and silicate on selenite uptake and phloem-mediated transport in tomato (Solanum lycopersicum L.).

The ambiguous mechanism that selenite seems to be absorbed by roots via phosphorus (P) and silicon (Si) transporters signifies P and Si may affect selenite uptake. However, the role of P and Si in phloem-mediated selenium (Se) transport within plant tissue is unknown. Therefore, in this work, tomato (Solanum lycopersicum L.) seedlings were exposed to selenite under different hydroponic conditions firstly. And then, split-root experiments were conducted. Results showed that Se uptake decreased as external pH increased. At pH 8, more selenite in the form of SeO32- was assimilated under P-deficient conditions than under P-normal conditions. Silicate inhibited Se uptake only at pH 3 (27.5% H2SeO3 +72.5% HSeO3-). The results of split-root experiments showed that Se concentrations in seedlings increased under heterogeneously high P or Si. Selenium transport from shoots to roots immersed in solution without selenite was also enhanced. This study illustrated that the affinity of tomato roots to assimilate selenite species followed the order of H2SeO3 >HSeO3- >SeO32-. H2SeO3 was absorbed into roots via Si transporters, whereas HSeO3- and a portion of SeO32- were absorbed via low- and high-affinity P transporters, respectively. In addition, heterogeneously high P or Si concentrations in environmental media could enhance phloem-mediated Se redistribution.

Impact of selection harvesting on the foliar chemistry of sugar maple seedlings established on base-poor soils in central Ontario, Canada

Sugar maple (Acer saccharum Marsh.) is a commercially important species throughout much of eastern North America and concerns have been raised regarding its successful regeneration owing to nutrient limitation, especially calcium (Ca) caused by acidic deposition. Timber harvesting can alter nutrient availability in soil, but the short-term effects of selection harvesting on sugar maple seedling chemistry have not been studied. In this study, sugar maple seedlings were collected for elemental analysis from unharvested areas, canopy gaps and skid trails one and two years post selection harvest in a mixed hardwood forest in central Ontario, Canada. Plant community composition and sugar maple seedling morphology were measured along with soil physical and chemical properties. While there were few measurable differences in soil physical or chemical characteristics amongst sites, understory vegetation was markedly different and Carex spp. were dominant in skid trails. In addition, sugar maple seedlings in the disturbed sites (gaps and skid trails) were morphologically different (decreased height:diameter ratio) and had lower foliar concentrations of essential plant nutrients including nitrogen (N), magnesium (Mg), potassium (K), and phosphorus (P) compared with unharvested sites. Calcium concentrations in seedlings were unaffected by harvesting, perhaps due to low soil Ca levels across all sites. In contrast to Ca, foliar concentrations of K and P in seedlings growing in gaps and skid trails were below or approached reported nutrient deficiency thresholds for mature trees, which may have potential consequences for forest regeneration that have not been previously considered.

Residual effects of biochar on growth, photosynthesis and cadmium uptake in rice (Oryza sativa L.) under Cd stress with different water conditions

Soil cadmium (Cd) contamination and drought stress are among the main issues hindering global food security. Biochar has been used to reduce metal uptake by plants and water stress mitigation, but long-term residual effects of biochar under Cd stress at different moisture levels needs to be investigated. A following rice (Oryza sativa L.) was grown after wheat on Cd-contaminated soil amended with different levels of biochar (0, 3.0, and 5.0%, w/w). Thirty five days old plants were irrigated with three moisture levels including zero drought as a control (1–2 cm water layer on soil), mild drought (MD, 50% of soil water holding capacity, WHC), and severe drought (SD, 35% of soil WHC) for an accompanying 35 days. Plant height, biomass and photosynthesis were reduced whereas oxidative stress increased under MD and SD than control in un-amended soil while opposite trends were observed in plants grown in biochar amended soil. At the same biochar addition, Cd concentrations in seedlings were lower in continuous flooding than MD and SD treatments. The biochar supply reduced the bioavailable Cd in the soil whereas increased the soil EC and pH than the control treatment. In conclusion, continuous flooding plus residual biochar can be strategized in mitigating Cd-contamination in paddy soils and decreased Cd concentrations in rice which may reduce the potential risks to humans.

Initial Growth and Compatible Solutes Concentration in Seedlings of two Genotypes of Psidium araca Raddi (Myrtaceae) in Response to Water Suppression

The physiological characterization of plants is of great importance to the selection of suitable genotypes tolerant of low water availability. Therefore, the aim of this study was to evaluate the influence of water deficit on growth and compatible solutes concentration of two genotypes of Psidium araca Raddi seedlings. The IPA 10/2 and IPA 16/2 genotypes behaved similarly in terms of number of leaves, stem diameter and the increase of root formation over shoot formation under water deficit. IPA 10/2 produced higher total dry matter; however, IPA 16/2 accession produced higher root-shoot ratio, carbohydrates and free proline contents, conferring to IPA 16/2 a greater ability to grow and survive in environments subjected to low water availability.
 Keywords: araça, biomass partitioning, carbohydrates, proline.

Growth and nitrogen uptake of jack pine seedlings in response to exponential fertilization and weed control in reclaimed soil

We evaluated the impact of exponential fertilization in nursery and weed removal in the field on growth and nitrogen (N) retranslocation and uptake from the soil of jack pine (Pinus banksiana Lamb.) seedlings planted on an oil sands reclaimed soil. Exponential fertilization is a method of supplying nutrients at an exponential rate to achieve constant internal nutrient concentrations in seedlings without changing their size during their growth in the nursery. The N retranslocation in seedlings was traced using 15N isotope labeling. Exponential fertilization increased nutrient reserve in the seedling in nursery production, and increased height (P = 0.003), root collar diameter (P < 0.001), total biomass (P < 0.001), and N content (P < 0.001) of seedlings at the end of first growing season in the field growth. Conventionally fertilized seedlings allocated a greater percent of biomass to roots than to current-year needles. The 15N isotope analysis showed that 59 to 82% of total N demand of new growth was met by retranslocation from old tissues. Exponential fertilization increased N retranslocation by 147% (P < 0.001) and N uptake from the soil by 175% (P = 0.012). Weed removal marginally increased (P = 0.077) N uptake from the soil but decreased (P = 0.046) N retranslocation with no net effect on total N content in new tissues. We conclude that exponential fertilization improves the early growth of jack pine and can help improve revegetation in reclaiming disturbed oil sands sites.

Comparison of silicon nanoparticles and silicate treatments in fenugreek

Silicon (Si) fertilization improves crop cultivation and is commonly added in the form of soluble silicates. However, most natural plant-available Si originates from plant formed amorphous SiO2 particles, phytoliths, similar to SiO2-nanoparticles (SiNP). In this work we, therefore, compared the effect by sodium silicate and that of SiNP on Si accumulation, activity of antioxidative stress enzymes catalase, peroxidase, superoxide dismutase, lignification of xylem cell walls and activity of phenylalanine ammonia-lyase (PAL) as well as expression of genes for the putative silicon transporter (PST), defensive (Tfgd 1) and phosphoenolpyruvate carboxykinase (PEPCK) and protein in fenugreek (Trigonella foenum-graecum L.) grown in hydroponics. The results showed that Si was taken up from both silicate and SiNP treatments and increasing sodium silicate addition increased the translocation of Si to the shoot, while this was not shown with increasing SiNP addition. The silicon transporter PST was upregulated at a greater level when sodium silicate was added compared with SiNP addition. There were no differences in effects between sodium silicate and SiNP treatments on the other parameters measured. Both treatments increased the uptake and accumulation of Si, xylem cell wall lignification, cell wall thickness, PAL activity and protein concentration in seedlings, while there was no effect on antioxidative enzyme activity. Tfgd 1 expression was strongly downregulated in leaves at Si addition. The similarity in effects by silicate and SiNP would be due to that SiNP releases silicate, which may be taken up, shown by a decrease in SiNP particle size with time in the medium.

Endogenous nitric oxide mediates He-Ne laser-induced adaptive responses in salt stressed-tall fescue leaves.

The aim of this study was to investigate the role of endogenous nitric oxide in protective effects of He-Ne laser on salt stressed-tall fescue leaves. Salt stress resulted in significant increases of membrane injury, reactive oxygen species (ROS) production, polyamine accumulation, and activities of SOD, POD, and APX, while pronounced decreases of antioxidant contents, CAT activity and intracellular Ca(2+) concentration in seedlings leaves. He-Ne laser illumination caused a distinct alleviation of cellular injury that was reflected by the lower MDA amounts, polyamine accumulation and ROS levels at the stress period. In contrast, the laser treatment displayed a higher Ca(2+) concentration, antioxidant amounts, NO release, antioxidant enzyme, and NOS activities. These responses could be blocked due to the inhibition of NO biosynthesis by PTIO (NO scavenger) or LNNA (NOS inhibitor). The presented results demonstrated that endogenous NO might be involved in the progress of He-Ne laser-induced plant antioxidant system activation and ROS degradation in order to enhance adaptive responses of tall fescue to prolonged saline conditions.

Effects of cumulative fertilization pattern on growth and nutrient concentrations of Chamaecyparis obtusa seedlings

ABSTRACTThe objective of this study was to investigate plant growth and nutrient uptake of Chamaecyparis obtusa seedlings with heavy fertilization treatment depending on previous fertilization experience. In a previous year, one-year-old Chamaecyparis obtusa seedlings were planted at a nursery with two levels of fertilization: the first group was fertilized with a mixed nitrogen–phosphorus (N-P) fertilizer of N 41.4 g m−2, P 18.3 g m−2 and the second group was unfertilized as a control. After one year, seedlings of similar height and root diameter were planted into 30-l pots and underwent two treatments: no fertilization for control and heavy fertilization with Basacote® 80 g pot−1. In the control, the plants’ growth exhibited no differences according to previous fertilization experience; in the case of heavily fertilized plants, seedlings which had experienced previous fertilization showed a 29% increase in height and a 63% increase in above-ground biomass production than did seedlings with no fertilization in the previous year. The biomass allocation to below-ground was low for the heavily fertilized seedlings regardless of previous treatments. N and P concentrations of the seedlings, measured at the leaf and root, were irrelevant to previous fertilization, but were higher in the heavily fertilized plants. This study suggests that previous fertilization experience at the nursery stage may reduce the stress induced by initial heavy fertilization during out-planting.

The activity of dung beetles increases foliar nutrient concentration in tropical seedlings

AbstractDung beetles are extensively used as a focal taxon in tropical forests. Yet, information for most of their ecological functions comes from other systems. We present results from a field experiment in a tropical rain forest showing that dung beetle activity increases foliar phosphorus concentration in seedlings of the tree Brosimum lactescens. Our results open new lines of research to assess the multiple effects that dung beetles may have on rain forest plants.

Engineered nanomaterials and crops: physiology and growth of barley as affected by nanoscale cerium oxide

In recent years, remarkable progress has been made in developing nanotechnology. This has led to a fast-growth of commercial applications, which involve the use of a great variety of manufactured nanomaterials. Given that, soils and sediments are the ultimate sinks of engineered nanomaterials (ENMs), they can be taken up by microorganisms, nematodes, earthworms or plants, and potentially transferred to the food chain up to animals and humans. However, the reactions of the biota exposed to ENMs of different size are still not well understood. Very few studies on nanoparticles-plant interactions have been published, so far. In this paper we report the results of multiple experiments carried out to study the effects of cerium oxide nanoparticles (nCeO2) on Hordeum vulgare. The nCeO2 powder and suspension were characterised for specific surface area, z-average size, and zeta potential. Germinating caryopses and barley seedlings were exposed to an aqueous dispersion of nCeO2 at respectively 0, 500, 1000 and 2000 mg L–1. Data on root elongation, mitotic index and cerium concentration in seedlings were collected. Plants of barley were grown to physiological maturity in soil enriched with respectively 500 and 1000 mg kg–1 of nCeO2. We reported that seed germination was not affected by the nCeO2, however, signals of genotoxicity were evidenced by mitotic index coupled with a shortage of root elongation. In the life-cycle experiment although no toxicity symptoms were detected, we demonstrated that barley growth was affected by nCeO2.