Hordeum Marinum Research Articles

Silicon (Si) enhances salt tolerance in sea barley (Hordeum marinum) by promoting growth, detoxifying reactive oxygen species, and stimulating antioxidant defense mechanisms

Silicon (Si) enhances salt tolerance in sea barley (Hordeum marinum) by promoting growth, detoxifying reactive oxygen species, and stimulating antioxidant defense mechanisms

Design of potential Ilp markers for Hordeum vulgare and H. marinum Atg2, Atg7, Atg8 genes

Aim. Design of potential intron length polymorphism markers for ATG2, ATG7, ATG8 genes. Methods. Use of classical bioinformatics methods to search for loci encoding ATG2, ATG7, ATG8 in the Hordeum marinum genome based on homology with cultivated barley genes; analysis of exon-intron structure of genes, design of ILP markers. Results. The sequences of ATG2, ATG7, ATG8 genes in H. marinum were determined. Analyzed differences in the exon-intron structure of the ATG2, ATG7, ATG8 loci in cultivated (H. vulgare) and salt-resistant wild barley (H. marinum). 25 potential ILP markers were designed for introns that showed significant interspecies length polymorphism: 13 for ATG2, 6 for ATG7, 3 for ATG8A, 2 for ATG8B and 1 for ATG8D. Conclusions. Based on gene structure comparative analysis of the autophagosome formation proteins ATG2, ATG7, ATG8 of cultivated H. vulgare and salt-tolerasnt H. marinum, a number of introns are recommended for further use as a potential source of ILP markers for the study of interspecies genetic differentiation of cereals.

Sea Barley (Hordeum Marinum) Seed Germination Ecology and Seedling Emergence

Sea barley is weedy grass in agricultural landscapes and infrastructure habitats (roads, railroads, etc.) in Golestan province (the northern part of Iran). This study investigated the germination of sea barley in response to temperature, water potentials, salinity, pH levels, waterlogging, heat stress and also seedling emergence in response to burial depth. Results showed that sea barley seeds germinated over a wide range of temperatures from 5 to 35 °C, with the highest germination at 25 °C. Seed germination was rapidly reduced with increasing osmotic potential so that germination declined by 36% at –0.2 MPa. This was also the case for the salinity stress, and germination declined by 30% at 40 mM NaCl. Seed germination was the highest (> 65%) in 6 to 7 pHs and no germination was observed at alkali levels. Heat stress completely inhibited the germination of seeds at all tested temperatures and durations. Sea barley seed germination was higher than 50% after being waterlogged for 45 days, and some germination (12%) still occurred 60 days after waterlogging. The highest seedling growth occurred at 1–2 cm soil depth and was negligible at ≥5 cm soil depths. The results of this study indicate that deep tillage or flamethrower may be good options to mitigate the negative impacts of this weed.

Salicylic Acid and Calcium Chloride Seed Priming: A Prominent Frontier in Inducing Mineral Nutrition Balance and Antioxidant System Capacity to Enhance the Tolerance of Barley Plants to Salinity.

The current investigation aims to underline the impact of salicylic acid or calcium chloride seed pre-treatments on mineral status and oxidative stress markers, namely levels of electrolyte leakage (EL) and lipid peroxidation levels, measured as thiobarbituric reactive substances (TBARS), and the activity of some antioxidant enzymes in roots and leaves of plants in two barley species grown under various salt treatments. Overall, our results revealed that salinity inhibits essential nutrient absorption such as iron, calcium, magnesium and potassium and stimulates the absorption of sodium. Also, this environmental constraint induced oxidative stress in plants in comparison with the control conditions. This state of oxidative stress is reflected by an increase in TBARS content as well as the stimulation of EL values. In addition, salinity induced disturbances in the activity of antioxidant enzymes, which were mainly dependent on the applied salt concentration and the species. In addition, Hordeum marinum maintained high antioxidant enzyme activity and low levels of oxidative stress parameters, which reinforces its salt-tolerant character. Importantly, salicylic acid or calcium chloride seed priming alleviated the mineral imbalance and the oxidative damage induced by salinity. Moreover, seed priming improves iron, calcium magnesium and potassium content and limitsthe accumulation of sodium. Also, both treatments not only decrease TBARS levels and limit EL, but they also stimulate the antioxidant enzyme activities in the leaves and roots of the stressed plants as compared with stressed plants grown from non-primed seeds. Interestingly, the beneficial effects of the mentioned treatments were more notable on Hordeum vulgare species.

Genetic variation in growth, ionic accumulation and salt tolerance indices under long-term salt stress in halophytic Tunisian sea barley (Hordeum marinum ssp. marinum)

Context Identification of salt-tolerant genetic resources is of high importance due to the constant increase in salt-affected areas. Aims This study was conducted to assess genetic variation in salt response among and within Tunisian sea barley populations and to identify useful genotypes for future breeding programmes directed towards improving salinity tolerance. Methods The salinity response of 141 lines from 10 natural populations of Hordeum marinum ssp. marinum was characterised at a morphophysiological level, following exposure to 200 mM sodium chloride for 90 days. Key results ANOVA revealed significant differences in growth and ion accumulation between and within populations in response to salinity. The Sebkhet Ferjouna population was less affected than Sidi Othman and Tabarka; however, it accumulated relatively higher sodium and lower potassium and potassium/sodium ratio. Stress Tolerance Index (STI) and Salt Tolerance (ST) values varied significantly among populations and lines. STI was positively correlated with potassium and negatively correlated with sodium content in roots and leaves, whereas no evidence of a relationship between both cations and ST was observed. Conclusions SO7, SO28, LB5, LB25, TB1, MT3 and BK12 with high values of STI were identified as high yielding lines in control and salt stress conditions, whereas MT3, BK12, MT17, BF10, SL8, SL16 and SF32, with the highest values of ST, were characterised by a small yield loss and low sensitivity when exposed to salinity. Implications These lines constitute a genetic resource with desirable adaptation characteristics for breeding programmes towards salinity tolerance in cultivated cereals.

Improving productivity and soil fertility in Medicago sativa and Hordeum marinum through intercropping under saline conditions

Background and aimsIntercropping is an agriculture system used to enhance the efficiency of resource utilization and maximize crop yield grown under environmental stress such as salinity. Nevertheless, the impact of intercropping forage legumes with annual cereals on soil salinity remains unexplored. This research aimed to propose an intercropping system with alfalfa (Medicago sativa)/sea barley (Hordeum marinum) to explore its potential effects on plant productivity, nutrient uptake, and soil salinity.MethodsThe experiment involved three harvests of alfalfa and Hordeum marinum conducted under three cropping systems (sole, mixed, parallel) and subjected to salinity treatments (0 and 150 mM NaCl). Agronomical traits, nutrient uptake, and soil properties were analyzed.Resultsrevealed that the variation in the measured traits in both species was influenced by the cultivation mode, treatment, and the interaction between cultivation mode and treatment. The cultivation had the most significant impact. Moreover, the mixed culture (MC) significantly enhanced the H. marinum and M. sativa productivity increasing biomass yield and development growth under salinity compared to other systems, especially at the second harvest. Furthermore, both intercropping systems alleviated the nutrient uptake under salt stress, as noted by the highest levels of K+/Na+ and Ca2+/Mg2+ ratios compared to monoculture. However, the intercropping mode reduced the pH and the electroconductivity (CEC) of the salt soil and increased the percentage of organic matter and the total carbon mostly with the MC system.ConclusionsIntercropped alfalfa and sea barely could mitigate the soil salinity, improve their yield productivity, and enhance nutrient uptake. Based on these findings, we suggest implementing the mixed-culture system for both target crops in arid and semi-arid regions, which further promotes sustainable agricultural practices.

Bacillus pumilus isolated from sabkha rhizosphere ameliorates the behavior of the facultative halophyte Hordeum marinum when salt-challenged by improving nutrient uptake and soil health-related traits

Plant growth-promoting rhizosphere bacteria (PGPR) are increasingly considered as highly efficient bioagents. They confer for instance better salt tolerance to host plants while improving soil enzyme activities and microbiome diversity, which are indicators of soil biological health and fertility. Here, the aim was to investigate the efficiency of native bacteria from saline rhizosphere of Hordeum marinum, in alleviating the adverse effects of salinity in this facultative halophyte with fodder potential. Following identification and characterization for salt tolerance capacity and in vitro plant growth promoting potential, the bacteria strain Bacillus pumilus, was selected for its ameliorative effects on H. marinum when cultivated under NaCl salinity (200 mM) in a greenhouse experiment. Salinity significantly restricted growth, induced oxidative stress and disturbed the mineral nutrition of H. marinum, whereas inoculation with B. pumilus significantly restored growth, as leaf elongation rate and plant dry weight. Similarly, the highest accumulation of K+, N and P were observed in inoculated plants challenged with salinity. This was concomitant with reduced MDA and H2O2 levels, thereby preventing oxidative damage in H. marinum plants cultivated under salt stress. Furthermore, B. pumilus strain also overcame salt impact via indirect mechanisms by activating soil enzymes (dehydrogenase, β-glucosidase and acid phosphatase) and microbial biomass C production. Overall, our data further highlight the environmental significance of microorganisms inhabiting extreme environments like sabkhas as promising agents for biological approaches aiming at saline soil rehabilitation and improving plant productivity when challenged with salinity, due to their beneficial effect on both plant and the rhizosphere.

Associate plant parasitic nematodes to weed species in some newly reclaimed lands

Plant-parasitic nematodes (PPNs) are vital soil organisms well-known to damage and reduce crop yield worldwide. Surveys were attempts to determine the impact of weed species on the communities and composition of nematodes in barley, wheat, quinoa, eggplant, and tomato crops in Alexandria and Ismailia regions of Egypt. During the surveys, eight occurring genera of nematodes were found namely; Meloidogyne spp, Pratylenchus spp, Helicotylenchus spp, Rotylenchulus spp, Xiphinema spp, Criconemoides spp, Ditylenchus spp, and Longidorus spp associated with the soil’s rhizosphere of 28 weed species belonging to 12 families. Among these weeds, Hordeum marinum and Sonchus oleraceus were good hosts to nematode species. Both wheat and barley had higher nematode diversity than quinoa in the winter season. Pratylenchus spp, Meloidogyne spp and Rotylenchulus spp can be considered vital potential PPNs with economic importance. Nematode abundances and structural indices varied greatly based on the host weed species, crop types and soil characteristics. A positive correlation was monitored among weeds, nematode frequencies and relative abundances as well as their crops. Finally, weed species are critical components in nematode communities that may increase the incidence and severity of nematode risks based on crop type and soil characteristics. Therefore weeds should be managed properly to diminish reservoir sites when developing nematode management options.

The complete chloroplast genome of Hordeum marinum ssp. marinum

Hordeum marinum ssp. marinum (Huds.) R. J. Soreng (2003) is a halophyte wild relative of barley and wheat, which exhibits remarkable salt tolerance characteristics. In this study, we presented the first characterization of the complete chloroplast genome of H. marinum ssp. marinum. Our findings reveal that the chloroplast genome of H. marinum ssp. marinum consists of a small single-copy region (SSC: 12,715 bp), a large single-copy region (LSC: 81,130 bp), and a pair of inverted repeat regions (IRs: 21,517 bp), amounting to a total length of 136,989 bp. The chloroplast genome encodes 139 genes, including 91 protein-coding genes, 38 tRNA genes, and ten rRNA genes. By utilizing phylogenetic analysis, we determine the evolutionary position of H. marinum in Triticeae. Our study provides valuable insights into the chloroplast genome of H. marinum ssp. marinum, which may have important implications for the improvement of cereal crops.

Development and characterization of a line with substitution of chromosome 4B of wheat Triticum aestivum L. on chromosome 4Hmar of wild barley Hordeum marinum ssp. gussoneanum (4x).

Introgressive hybridization is the main method of broadening the genetic diversity of bread wheat. Wild barley Hordeum marinum ssp. gussoneanum Hudson (2n = 4x = 28) has useful agronomical traits, such as high resistance to stress factors, that could be a potential source of new genes for bread wheat improvement. This study aimed to evaluate the possibility of introgression of H. marinum chromosomes into the genome of bread wheat using an incomplete amphiploid H. marinum ssp. gussoneanum (4x)-T. aestivum (Pyrotrix 28) (2n = 54) carrying the cytoplasm of wild barley. For this purpose, we crossed the line of bread wheat variety Pyrotrix 28 with an incomplete amphiploid, and then selected cytogenetically stable 42-chromosome plants with a high level of fertility in hybrid progeny. Genomic in situ hybridization (GISH) revealed a pair of H. marinum chromosomes in the genome of these plants. C- banding analysis confirmed that bread wheat chromosome 4B was replaced by wild barley chromosome 4Hmar. SSR markers Xgwm368 and Xgwm6 confirmed the absence of chromosome 4B, and EST markers BAWU808 and BAW112 identified chromosome 4Hmar in the genome of the isolated disomic wheat-barley substitution line. The study of this line showed that the substitution of chromosome 4B with chromosome 4Hmar resulted in a change of some morphological traits. It included intense anthocyanin coleoptile coloration, specific for H. marinum, as well as a lack of purple coloration of the ears in the leaf sheath, specific for Pyrotrix 28. Line 4Hmar(4B) showed increased performance for several traits, including plant height, number of spikes and tillers per plant, spikelet and grain number in the main spike, grain number per plant, but it had decreased values of 1000-grain weight compared to wheat. Cytogenetic stability and fertility of line 4Hmar(4B) indicated a high compensation ability of barley 4Hmar for wheat chromosome 4B and confirmed their homeology.

Exploring Wild Hordeum spontaneum and Hordeum marinum Accessions as Genetic Resources for Fungal Resistance.

Crop Wild Relatives (CWRs), as potential sources of new genetic variants, are being extensively studied to identify genotypes that will be able to confer resistance to biotic stresses. In this study, a collection of barley wild relatives was assessed in the field, and their phenotypic variability was evaluated using a Barley Description List, reflecting the identified ecosites. Overall, the CWRs showed significant field resistance to various fungal diseases. To further investigate their resistance, greenhouse tests were performed, revealing that several CWRs exhibited resistance against Fusarium culmorum, Pyrenophora teres, and Puccinia hordei G.H. Otth. Additionally, to characterize the genetic diversity within the collection, DNA polymorphisms at 21 loci were examined. We successfully employed barley-specific SSR markers, confirming their suitability for identifying H. spontaneum and even H. marinum, i.e., perennial species. The SSR markers efficiently clustered the investigated collection according to species and ecotypes, similarly to the phenotypic assessment. Moreover, SSR markers associated with disease resistance revealed different alleles in comparison to those found in resistant barley cultivars. Overall, our findings highlight that this evaluated collection of CWRs represents a valuable reservoir of genetic variability and resistance genes that can be effectively utilized in breeding programs.

Silicon (Si) Treatment has Preferential Beneficial Effects on Photosystem I Photochemistry in Salt-Treated Hordeum marinum (Huds.) Plants

Silicon (Si) Treatment has Preferential Beneficial Effects on Photosystem I Photochemistry in Salt-Treated Hordeum marinum (Huds.) Plants

Morphological and physiological behaviour of sea barley (Hordeum marinum ssp marinum) genotypes originating from Soliman Sebkha under increasing salinity

Evaluation of germplasm in salt stress environment may help identifying salt-tolerant genotypes. In this study, we analyzed the genetic diversity of Hordeum marinum, genotypes originated from Soliman Sebkha in response to salinity (0, 250 and 400 mM) by measuring a set of parameters related to growth, water statue and photosynthetic activity. Results of ANOVA showed that variability of measured parameters was explained by the effects genotypes, treatment and their interaction, with treatment factor recorded the highest values. Salinity significantly reduced the photosynthetic rate and related parameters, including stomatal conductance (gs), intercellular CO2 concentration (Ci), and transpiration (E). Several indices for salt tolerance indices comprising tolerance index (TOL), stress tolerance index (STI) and Salt Tolerance (ST) were calculated based on drought biomass (ADW) under non-stressed and under stress conditions. Results showed that lower values of TOL and higher values of ST and STI indicate the superiority of the genotypes having enough plasticity to respond to extreme conditions. Principal Component Analysis clustered genotypes into sensitive (21.43%), moderately tolerant (50%), and highly tolerant (28.57%) groups, depending on their relative potential to sustain good growth under high salinity. Results indicating sufficient genetic variability for salinity tolerance among the studied genotypes, hence tolerant genotypes can be good candidates in future breeding programs.

Mitigation of salt stress and stimulation of growth by salicylic acid and calcium chloride seed priming in two barley species

The main objective of the current study is to underline the effects of salicylic acid or calcium chloride seed priming on plant growth, water content, chlorophyll content and photosynthetic activity of two barley species Hordeum marinum and Hordeum vulgare exposed to salinity (0, 100 and 200 mM NaCl). Results revealed that salinity decreased shoot and root growth, transpiration rate, chlorophyll concentration, stomata conductivity and water content in plants obtained from unprimed seeds. This reduction was dependent on the saline concentration used. However, Hordeum marinum species showed tolerance by maintaining tissue hydration, growth, photosynthetic assimilation and chlorophyll biosynthesis in stressed plants compared to controls. Moreover, priming seeds with salicylic acid or calcium chloride significantly improved all the above parameters under different salt treatments, suggesting that the effectiveness of this approach mainly depends on the priming agent applied and may vary with species and stress intensity applied.

The genome and gene editing system of sea barleygrass provide a novel platform for cereal domestication and stress tolerance studies

The tribe Triticeae provides important staple cereal crops and contains elite wild species with wide genetic diversity and high tolerance to abiotic stresses. Sea barleygrass (Hordeum marinum Huds.), a wild Triticeae species, thrives in saline marshlands and is well known for its high tolerance to salinity and waterlogging. Here, a 3.82-Gb high-quality reference genome of sea barleygrass is assembled de novo, with 3.69 Gb (96.8%) of its sequences anchored onto seven chromosomes. In total, 41 045 high-confidence (HC) genes are annotated by homology, de novo prediction, and transcriptome analysis. Phylogenetics, non-synonymous/synonymous mutation ratios (Ka/Ks), and transcriptomic and functional analyses provide genetic evidence for the divergence in morphology and salt tolerance among sea barleygrass, barley, and wheat. The large variation in post-domestication genes (e.g. IPA1 and MOC1) may cause interspecies differences in plant morphology. The extremely high salt tolerance of sea barleygrass is mainly attributed to low Na+ uptake and root-to-shoot translocation, which are mainly controlled by SOS1, HKT, and NHX transporters. Agrobacterium-mediated transformation and CRISPR/Cas9-mediated gene editing systems were developed for sea barleygrass to promote its utilization for exploration and functional studies of hub genes and for the genetic improvement of cereal crops.

Typification of two names in the genus Hordeum (Poaceae, Triticeae)

The typification of the name Hordeum marinum Hudson (Poaceae) is discussed. The name is lectotypified using an original illustration from Morison’s Plantarum historiae universalis Oxoniensis, and an epitype is also selected. The type of the name H. gussoneanum is also discussed, and a specimen preserved at FI is designated as second step lectotype.

The Halophyte Dehydrin Sequence Landscape.

Dehydrins (DHNs) belong to the LEA (late embryogenesis abundant) family group II, that comprise four conserved motifs (the Y-, S-, F-, and K-segments) and are known to play a multifunctional role in plant stress tolerance. Based on the presence and order of these segments, dehydrins are divided into six subclasses: YnSKn, FnSKn, YnKn, SKn, Kn, and KnS. DHNs are rarely studied in halophytes, and their contribution to the mechanisms developed by these plants to survive in extreme conditions remains unknown. In this work, we carried out multiple genomic analyses of the conservation of halophytic DHN sequences to discover new segments, and examine their architectures, while comparing them with their orthologs in glycophytic plants. We performed an in silico analysis on 86 DHN sequences from 10 halophytic genomes. The phylogenetic tree showed that there are different distributions of the architectures among the different species, and that FSKn is the only architecture present in every plant studied. It was found that K-, F-, Y-, and S-segments are highly conserved in halophytes and glycophytes with a few modifications, mainly involving charged amino acids. Finally, expression data collected for three halophytic species (Puccinillia tenuiflora, Eutrema salsugenium, and Hordeum marinum) revealed that many DHNs are upregulated by salt stress, and the intensity of this upregulation depends on the DHN architecture.

The mechanisms for the difference in waterlogging tolerance among sea barley, wheat and barley

The mechanisms for the difference in waterlogging tolerance among sea barley, wheat and barley

Silicon (Si) Alleviates Iron Deficiency Effects in Sea Barley (Hordeum marinum) by Enhancing Iron Accumulation and Photosystem Activities

Silicon (Si) Alleviates Iron Deficiency Effects in Sea Barley (Hordeum marinum) by Enhancing Iron Accumulation and Photosystem Activities

Adaptation Strategies of Halophytic Barley Hordeum marinum ssp. marinum to High Salinity and Osmotic Stress.

The adaptation strategies of halophytic seaside barley Hordeum marinum to high salinity and osmotic stress were investigated by nuclear magnetic resonance imaging, as well as ionomic, metabolomic, and transcriptomic approaches. When compared with cultivated barley, seaside barley exhibited a better plant growth rate, higher relative plant water content, lower osmotic pressure, and sustained photosynthetic activity under high salinity, but not under osmotic stress. As seaside barley is capable of controlling Na+ and Cl− concentrations in leaves at high salinity, the roots appear to play the central role in salinity adaptation, ensured by the development of thinner and likely lignified roots, as well as fine-tuning of membrane transport for effective management of restriction of ion entry and sequestration, accumulation of osmolytes, and minimization of energy costs. By contrast, more resources and energy are required to overcome the consequences of osmotic stress, particularly the severity of reactive oxygen species production and nutritional disbalance which affect plant growth. Our results have identified specific mechanisms for adaptation to salinity in seaside barley which differ from those activated in response to osmotic stress. Increased knowledge around salt tolerance in halophytic wild relatives will provide a basis for improved breeding of salt-tolerant crops.