How could actinobacteria augment the growth and redox homeostasis in barley plants grown in TiO2NPs-contaminated soils? A growth and biochemical study

The increases in titanium dioxide nanoparticles (TiO2-NPs) released into the environment have raised concerns about their toxicity. However, their phytotoxic impact on plants is not well studied. Therefore, this study aimed at a deeper understanding of the TiO2-NPs phytotoxic impact on barley (Hordeum vulgare) growth and stress defense. We also hypothesized that soil inoculation with bioactive Rhodospirillum sp. JY3 strain can be applied as a biological fertilizer to alleviate TiO2-NPs phytotoxicity. At TiO2-NPs phytotoxicity level, photosynthesis was significantly retarded (∼50% reduction) in TiO2-NPs treated-barley plants which accordingly affect the biomass of barley plants. This retardation was accompanied by a remarkable induction of oxidative damage (H2O2, lipid peroxidation) with a concomitant reduction in the antioxidant defense metabolism. At a glance, Rhodospirillum sp. JY3 ameliorated the reduction in growth by enhancing the photosynthetic efficiency in contaminated barley plants. Moreover, Rhodospirillum sp. JY3 inoculation reduced the oxidative damage induced by TiO2-NPs via quenching H2O2 production and lipid peroxidation. Regarding the antioxidant defense arsenal, Rhodospirillum sp. JY3 enhanced both enzymatic (e.g. peroxidase (POX), catalase (CAT), superoxide dismutase (SOD), …. etc.) and non-enzymatic (glutathione (GSH), ascorbate (ASC), polyphenols, flavonoids, tocopherols) antioxidants in shoots and to a greater extent roots of barley plants. Moreover, the inoculation significantly enhanced the heavy metal-detoxifying metabolites (eg. phytochelatins, glutaredoxin, thioredoxin, peroxiredoxin) as well as metal-detoxifying enzymes in barley shoots and more apparently in roots of TiO2-NPs stressed plants. Furthermore, there was an organ-specific response to TiO2-NPs and Rhodospirillum sp. JY3. To this end, this study shed light, for the first time, on the molecular bases underlie TiO2-NPs stress mitigating impact of Rhodospirillum sp. JY3 and it introduced Rhodospirillum sp. JY3 as a promising eco-friendly tool in managing environmental risks to maintain agricultural sustainability.

Untargeted Metabolomics Approach Correlated Enniatin B Mycotoxin Presence in Cereals with Kashin-Beck Disease Endemic Regions of China

Kashin-Beck disease (KBD) is a multifactorial endemic disease that only occurs in specific Asian areas. Mycotoxin contamination, especially from the Fusarium spp., has been considered as one of the environmental risk factors that could provoke chondrocyte and cartilage damage. This study aimed to investigate whether new mycotoxins could be identified in KBD-endemic regions as a potential KBD risk factor. This was investigated on 292 barley samples collected in Tibet during 2009-2016 and 19 wheat samples collected in Inner Mongolia in 2006, as control, from KBD-endemic and non-endemic areas. The LC-HRMS(/MS) data, obtained by a general mycotoxin extraction technic, were interpreted by both untargeted metabolomics and molecular networks, allowing us to identify a discriminating compound, enniatin B, a mycotoxin produced by some Fusarium spp. The presence of Fusarium spp. DNA was detected in KBD-endemic area barley samples. Further studies are required to investigate the role of this mycotoxin in KBD development in vivo.

Quantitative TMT-based proteomics revealing host, dietary and microbial proteins in bovine faeces including barley serpin Z4, a prominent component in the head of beer

There has been little information about the proteome of bovine faeces or about the contribution to the faecal proteome of proteins from the host, the feed or the intestinal microbiome. Here, the bovine faecal proteome and the origin of its component proteins was assessed, while also determining the effect of treating barley, the major carbohydrate in the feed, with either ammonia (ATB) or sodium propionate (PTB) preservative. Healthy continental crossbreed steers were allocated to two groups and fed on either of the barley-based diets. Five faecal samples from each group were collected on Day 81 of the trial and analysed by quantitative proteomics using nLC-ESI-MS/MS after tandem mass tag labelling. In total, 281 bovine proteins, 199 barley proteins, 176 bacterial proteins and 190 archaeal proteins were identified in the faeces. Mucosal pentraxin, albumin and digestive enzymes were among bovine proteins identified. Serpin Z4 a protease inhibitor was the most abundant barley protein identified which is also found in barley-based beer, while numerous microbial proteins were identified, many originating bacteria from Clostridium, while Methanobrevibacter was the dominant archaeal genus. Thirty-nine proteins were differentially abundant between groups, the majority being more abundant in the PTB group compared to the ATB group. SIGNIFICANCE: Proteomic examination of faeces is becoming a valuable means to assess the health of the gastro-intestinal tract in several species, but knowledge on the proteins present in bovine faeces is limited. This investigation aimed to characterise the proteome of bovine faecal extracts in order to evaluate the potential for investigations of the proteome as a means to assess the health, disease and welfare of cattle in the future. The investigation was able to identify proteins in bovine faeces that had been (i) produced by the individual cattle, (ii) present in the barley-based feed eaten by the cattle or (iii) produced by bacteria and other microbes in the rumen or intestines. Bovine proteins identified included mucosal pentraxin, serum albumin and a variety of digestive enzymes. Barley proteins found in the faeces included serpin Z4, a protease inhibitor that is also found in beer having survived the brewing process. Bacterial and archaeal proteins in the faecal extracts were related to several pathways related to the metabolism of carbohydrates. The recognition of the range of proteins that can be identified in bovine faeces raises the possibility that non-invasive sample collection of this material could provide a novel diagnostic approach to cattle health and welfare.

Irrigated barley-grass pea crop mixtures can revive soil microbial activities and alleviate salinity in desertic conditions of southern Morocco

Soil salinity adversely limits crop and soil health, and this can be reversed by cropping systems where species exclude salts and activate microbial nutrient cycling. A randomized complete block design experiment was established in Laayoune-Morocco to evaluate the influence of irrigated grass pea and barley monocrops or combined together in 50-50% and 70-30% mixtures against soil salinity and CO2-C flux in sites with varying salinity. Site by treatment interaction significantly influenced (p < 0.05) soil salinity and CO2-C flux. Salinity reduced by 37 to 68 dS m-1 in highly saline soils across season regardless of treatment and barley monocrop retained the least salinity (15 dS m-1). Same applied to sites with low (1 to 2 dS m-1) and medium (2 to 5 dS m-1) salinity although less pronounced. The 70-30% grass pea, barley mixture maintained the greatest CO2-C flux in soils with low salinity and marginally enhancing soil active carbon (130 to 229 mg kg-1 soil) in different sites. Increasingly saline water filled pore space devastated CO2-C flux, although this process recovered under barley at extreme salinity. Overall, barley in mixture with grass pea can alleviate salinity and accelerate microbial carbon sequestration if irrigation is modulated in shallow desertic soils.

Barley yield and malt quality affected by fall and spring planting under rainfed conditions

Background

As a result of the changing climate characteristics, it is necessary to reevaluate the planting time for crop plants. The aim of the present study was to determine the quality characteristics of malting barley cultivars in fall and spring plantings.

Methods

Sixteen malting barley cultivars were used. Two fall-planted and two spring-planted trials were conducted in two consecutive years. The field trials were carried out in a randomized complete block design with four replications in Tokat province of Turkey under rainfed conditions.

Results

Grain yields varied between 4.38 and 5.71 t/ha in fall-planted trials and between 3.12 and 4.89 t/ha in spring-planted trials. Malt extracts were between 77.0% and 78.0% kg in fall-planted trials and between 73.9% and 76.9% in spring-planted trials. Alpha amylase activities ranged from 77.9 to 81.4 Ceralpha unit (CU)/g in fall-planted trials and from 80.8 to 100.9 CU/g in spring-planted trials. Diastatic power ranged from 194.5 to 331.1 Windisch-Kolbach unit (°WK) in fall-planted trials and from 129.0 to 259.8 °WK in spring-planted trials. GGE biplot analysis indicated that winter barley cultivar Durusu and facultative barley cultivar Ince-04 were the best with consistent grain yields while Ince-04 was the best with stable malt extract across the trials. In scatter plot graphics, winter barley cultivars Durusu, Aydanhanim, Yildiz and facultative Ince-04 had superior performance in fall-plantings for grain yield and malt extract. In spring planting, facultative Ince-04 had higher performance than those of other cultivars. In spring plantings, facultative or winter barley cultivars that do not have strong vernalization requirement had better yield and malt quality. Appropriate planting time and cultivars can allow a better use of available water in malt barley production under rainfed conditions. Lastly, instead of evaluating the grain yield or malt quality alone, it would be best to evaluate the target product (malt extract percentage) obtained from a particular region, process, or production methodology.

Different protein sources in concentrate feed for dairy cows affect cheese-making properties and yield

Soybean meal (SBM) is a commonly used protein source in feed. Yeast microbial protein could be used as a substitute for SBM, but its effect on cheese-making properties and yield is not known. Norwegian Red dairy cows (n = 48) in early or mid lactation were divided in 3 groups and fed a ration consisting of grass silage and concentrate, where the concentrates were barley based but with different additional protein sources. These were: completely barley based with no additional protein source (BAR), additional protein from SBM, or additional protein from yeast (Cyberlindnera jadinii; YEA). The SBM and YEA concentrates had a higher protein content than the barley concentrate. Four batches of cheese were made from pooled milk from each of the 3 groups of dairy cows. Milk samples were collected 5 times during the experiment. Milk from cows fed BAR concentrate showed inferior cheese-making properties (lower casein content, longer renneting time, lower content of phosphorus, and lower cheese yield) compared with SBM and YEA concentrates. Overall, SBM or YEA bulk milk had similar cheese-making properties, but when investigating individual milk samples, YEA milk showed better coagulation properties.

Prevalence and Importance of the Necrotrophic Effector Gene ToxA in Bipolaris sorokiniana Populations Collected from Spring Wheat and Barley

Bipolaris sorokiniana is a necrotrophic fungal pathogen that causes foliar and root diseases on wheat and barley. These diseases are common in all wheat- and barley-growing regions, with more severe outbreaks occurring under warm and humid conditions. B. sorokiniana can also infect a wide range of grass species in the family Poaceae and secrete ToxA, an important necrotrophic effector also identified other wheat leaf spotting pathogens. In this study, the prevalence and virulence role of ToxA were investigated in a collection of 278 B. sorokiniana isolates collected from spring wheat and barley in the Upper Midwest of the United States or other places, including 169 from wheat leaves, 75 from wheat roots, 30 from barley leaves, and 4 from wild quack grass leaves. ToxA was present in the isolates from wheat leaves, wheat roots, and wild grass leaves but was absent from isolates collected from barley leaves. Prevalence of ToxA in wheat leaf isolates (34.3%) was much higher than that in wheat root isolates (16%). Sequencing analysis revealed the presence of two haplotypes, with the majority being BsH2. All ToxA+ isolates produced the functional effector in liquid cultures. Pathogenicity assays revealed that ToxA+ isolates caused significantly more disease on spring wheat lines harboring Tsn1 than their tsn1 mutants, suggesting that the ToxA-Tsn1 interaction plays an important role in spot blotch development. This work confirms the importance of ToxA in B. sorokiniana populations infecting wheat and, thus, the need to eliminate Tsn1 from spring wheat cultivars to reduce susceptibility to spot blotch.

Differences in Ratio of Carbon Stable Isotopes among Barley Grain Milling Fractions with Various Concentrations of Beta-Glucans

The grains of three barley varieties were milled and sieved to obtain respective milling fractions with a content of beta-glucans (b-G) from 1.4 to 10.7%. The enriched fraction obtained by the extraction and precipitation contained 24.7% of b-G. The differences between the ratio of stable C carbon isotopes were established. Milling fractions with coarse particles had more beta-glucans and a more negative ratio of δ13C isotope in comparison to the respective intact barley grain. However, the enriched fraction had a less negative isotope ratio. So, it is not expected that the deviation from the stable isotope ratio of grain in milling fractions is the result of the content of b-G, but it depends on other barley grain constituents. In different parts of barley grain, there are substances with different stable isotope ratios, and by milling and sieving, they are assorted to the same milling fraction with most of the b-G. The method for determining the ratio of a stable carbon isotope in diverse barley grain fractions, applied in this investigation, is potentially opening the possibility for an additional method of screening the concentration of bioactive constituents in barley grain.

RNA-seq analysis reveals an immunomodulatory peptide from highland barley activating RAW264.7 macrophages via TNF/NF-κB signaling pathway

Highland barley (HB) is an important cereal crop distributed in the plateau region. Bioactive peptides (BAPs) derived from cereal proteins have shown biological functions. However, the knowledge of highland barley peptide (HBP) is limited. This study aims to explore the immunomodulatory activity of HBP and the relationship between immunomodulatory activity and related gene expression through RNA-seq. Firstly, HBP is isolated from protease hydrolysates of HB protein, yielding 12.04% of crude HB protein. The molecular weight of HBP is about 1702 Da analyzed by gel filtration chromatography, and HBP has a specific amino acid sequence as Gln-Pro-Gln-Gln-Pro-Phe-Pro-Gln (QPQPFPQ) analyzed by LC-MS. Besides, HBP contains 42.20% hydrophobic amino acids and 10.86% basic amino acids. Next, the immunomodulatory activity of HBP in vitro shows that HBP enhances the phagocytosis of RAW264.7 macrophages, promotes nitric oxide (NO) production and the mRNA expression of pro-inflammatory genes including tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and inducible nitric oxide synthase (iNOS), and decreases the mRNA expression of anti-inflammatory gene, transforming growth factor β1 (TGF-β1). RNA-seq analysis reveals TNF and nuclear factor kappa B (NF-κB) pathways are upregulated, and RT-qPCR is performed to verify RNA-seq analysis. In conclusion, HBP activates RAW264.7 macrophages via TNF/NF-κB signaling pathway. HBP, as a significant immunomodulatory peptide, might be a promising resource for future functional foods.

Insights into the modification of physicochemical properties and digestibility of pea starch gels with barley β-glucan

The influences of barley β-glucan (BBG) on the physicochemical properties and in vitro digestibility of pea starch were investigated. BBG was found to decrease pasting viscosity in a concentration dependent manner and inhibited the aggregation of pea starch. After the presence of BBG, the gelatinization enthalpy of pea starch was decreased (from 7.83 ± 0.03 to 5.55 ± 0.22 J/g), whereas the gelatinization temperature was enhanced (from 62.64 ± 0.01 to 64.52 ± 0.14°C) according to the differential scanning calorimeter results. In addition, BBG inhibited the swelling of pea starch and amylose leaching. When amylose leached out from pea starch to form a BBG-amylose barrier, starch gelatinization was inhibited. The starch gels exhibited weak gels and shear thinning behaviors by rheological tests results. The interaction between BBG and amylose led to lower viscoelasticity and texture parameters in pea starch gels. The structure analysis results unveiled that the force between BBG and amylose was mainly hydrogen bonds. Pea starch hydrolysis was inhibited when BBG was present in the system, which was connected with the restricted starch gelatinization. These results obtained in the study would supply insights into incorporating BBG into various food systems.

Influence of relay intercropping of barley with chickpea on biochemical characteristics and yield under water stress

Relay intercropping of legumes with cereals is a useful technique for yield increment. Intercropping may affect the photosynthetic pigments, enzyme activity and yield of barley and chickpea under water stress. To investigate the effect of relay intercropping of barley with chickpea on pigment content, enzyme activity and yield under water stress, a field experiment was conducted during 2017 and 2018. The treatments included irrigation regimes (normal irrigation and cutting off irrigation at the milk development stage) as the main plot. Also, cropping systems as sub plot consisted of sole and relay intercropping of barley with chickpea in two sowing dates (December vs January). Under water stress, the early establishment of barley in December intercropped with chickpea in January (b1c2) enhanced the leaf chlorophyll content by 16% compared to sole cropping due to less competition with chickpea. Late sowing of chickpea enhanced the leaf carotenoid content of chickpea, catalase and peroxidase activities. Barley-chickpea intercropping enhanced the WUE and guaranteed a more efficient use of space (land equivalent ratio of more than 1) compared with sole crops. Under water stress, in b1c2 enhancement of total chlorophyll and water use efficiency caused to increase the grain yield of barley. In b1c2, barley and chickpea reacted to water stress with increasing total chlorophyll and enzyme activity, respectively. In this relay intercropping treatment, each crop occupied and used the growth resources from different ecological niches at different times, which is recommended in semi-arid areas.

Convergently selected NPF2.12 coordinates root growth and nitrogen use efficiency in wheat and barley

Understanding the genetic and molecular function of nitrate sensing and acquisition across crop species will accelerate breeding of cultivars with improved nitrogen use efficiency (NUE). Here, we performed a genome-wide scan using wheat and barley accessions characterized under low and high N inputs that uncovered the NPF2.12 gene, encoding a homolog of the Arabidopsis nitrate transceptor NRT1.6 and other low-affinity nitrate transporters that belong to the MAJOR FACILITATOR SUPERFAMILY. Next, it is shown that variations in the NPF2.12 promoter correlated with altered NPF2.12 transcript levels where decreased gene expression was measured under low nitrate availability. Multiple field trials revealed a significantly enhanced N content in leaves and grains and NUE in the presence of the elite allele TaNPF2.12^TT grown under low N conditions. Furthermore, the nitrate reductase encoding gene NIA1 was up-regulated in npf2.12 mutant upon low nitrate concentrations, thereby resulting in elevated levels of nitric oxide (NO) production. This increase in NO correlated with the higher root growth, nitrate uptake, and N translocation observed in the mutant when compared to wild-type. The presented data indicate that the elite haplotype alleles of NPF2.12 are convergently selected in wheat and barley that by inactivation indirectly contribute to root growth and NUE by activating NO signaling under low nitrate conditions.

Formulation and characterization of sustainable bioadhesive films for wound treatment based on barley β-glucan extract obtained using the high power ultrasonic technique

β-glucan is a well-known functional and bioactive food ingredient. Recently, some studies highlighted several interesting pharmacological activities, such as hypocholesterolemic, hypoglycemic, immunomodulatory, antitumor, antioxidant and anti-inflammatory. The aim of this study is to evaluate a novel application of β-glucan, obtained from barley, for the development of formulations for skin use. Several water suspensions were obtained from barley flour of different particle sizes treated by high power ultrasonic (HPU) technique. Barley flour fraction in the range of 400-500 μm allowed to obtain a stable suspension, represented both by a water soluble and water insoluble fraction of β-glucans, that showed excellent film forming ability. The plasticizer sorbitol as well as the bioadhesive biopolymer acacia gum were added to this suspension in order to obtain a gel suitable to prepare films by casting. The obtained films demonstrated suitable mechanical properties and ability to stimulate in vitro keratinocytes growth suggesting its possible application in dermatological field as for wound treatment. This study demonstrated the dual use of barley suspension: as excipient and as active ingredient.

An exotic allele of barley EARLY FLOWERING 3 contributes to developmental plasticity at elevated temperatures

Increase in ambient temperatures caused by climate change affects various morphological and developmental traits of plants, threatening crop yield stability. In the model plant Arabidopsis thaliana, EARLY FLOWERING 3 (ELF3) plays prominent roles in temperature sensing and thermomorphogenesis signal transduction. However, how crop species respond to elevated temperatures is poorly understood. Here, we show that the barley ortholog of AtELF3 interacts with high temperature to control growth and development. We used heterogeneous inbred family (HIF) pairs generated from a segregating mapping population and systematically studied the role of exotic ELF3 variants in barley temperature responses. An exotic ELF3 allele of Syrian origin promoted elongation growth in barley at elevated temperatures, whereas plant area and estimated biomass were drastically reduced, resulting in an open canopy architecture. The same allele accelerated inflorescence development at high temperature, which correlated with early transcriptional induction of MADS-box floral identity genes BM3 and BM8. Consequently, barley plants carrying the exotic ELF3 allele displayed stable total grain number at elevated temperatures. Our findings therefore demonstrate that exotic ELF3 variants can contribute to phenotypic and developmental acclimation to elevated temperatures, providing a stimulus for breeding of climate-resilient crops.

Predacious Natural Enemies Associated With Suppression of Onion Thrips, Thrips tabaci (Thysanoptera: Thripidae), in Intercropped Onion-Barley Agroecosystems

The effects of two possible factors, prevention of pest immigration and enhancement of natural enemies, in suppressing onion thrips, Thrips tabaci L., were estimated in a small-scale experimental system of spring-planted onions intercropped with barley. The population dynamics of the thrips and their potential predatory natural enemies were investigated in four treatments: control (bare ground), insect net barrier, and onion-barley intercropping with or without trimming. We found that intercropping significantly suppressed onion thrips. It is unlikely that this effect was due to the prevention of thrip immigration because they seemed to move over the camouflage and/or physical barriers of the barley and the net barrier surrounding the onions easily. Intercropping with barley significantly increased hoverfly (Syrphidae) larvae numbers on onion leaves, and that of some groups of ground-dwelling predators such as large carnivorous ground beetles (Carabidae), ants (Formicidae), and wolf spiders (Lycosidae). We conclude that the suppression of thrips in this system was associated with the enhancement of hoverfly larvae abundance, mainly Sphaerophoria macrogaster (Thomson) (Syrphidae: Diptera) because they were observed together with thrips on onions and have been reported to predate thrips as well as aphids. Some hoverfly larvae on barley might move to nearby onions to search for new food sources and attack thrips.

Speciation of macro- and nanoparticles of Cr2O3 in Hordeum vulgare L. and subsequent toxicity: A comparative study

Chromium (Cr) is reported to be hazardous to environmental components and surrounding biota when levels exceed allowable thresholds. As Cr is extensively utilized in different industries, thereby comprehensively studied for its toxicity. Along with Cr, the applications of nano-Cr or chromium oxide nanoparticles (Cr₂O₃-NPs) are also expanding; however, the literature is scarce or limited on their phytotoxicity. Thereby, the current work investigated the morpho-physiological insights of macro- and nanoparticles of Cr in Hordeum vulgare L. plants. The increased accumulation and translocation of Cr under the exposure of both forms disturbed the cellular metabolism that might have inhibited germination and growth as well as interfered with the photosynthesis of plants. The overall extent of toxicity was noticeably higher under nanoparticles' exposure than macroparticles of Cr. The potential cue for such phytotoxic consequences mediated by Cr nanoparticles could be an increased bioavailability of Cr ions which was also supported by their total content, mobility, and factor toxicity index. Besides, to support further these findings, synchrotron X-ray technique was used to reliably identify Cr-containing compounds in the plant tissues. The X-ray spectra of the near spectral region and the far region of the spectrum of K-edge of Cr were obtained, and it was established that the dominant crystalline phase corresponds to Cr₂O₃ (eskolaite) from the recorded observations. Thus, the obtained results would allow revealing the mechanism of macro- and nanoparticles of Cr induced impacts on plant at the tissue, cellular- and sub-cellular levels.

LDPE and biodegradable PLA-PBAT plastics differentially affect plant-soil nitrogen partitioning and dynamics in a Hordeum vulgare mesocosm

Micro and macroplastics are emerging contaminants in agricultural settings, yet their impact on nitrogen (N) cycling and partitioning in plant-soil-microbial systems is poorly understood. In this mesocosm-scale study, spring barley (Hordeum vulgare L.) was exposed to macro or microplastic produced from low density polyethylene (LDPE) or biodegradable plastic at concentrations equivalent to 1, 10 and 20 years of plastic mulch film use. Partitioning of ¹⁵N-labelled fertiliser into plant biomass, soil and leachate yielded a partial mass balance. Soil N partitioning was probed via compound-specific ¹⁵N-stable isotope analyses of soil microbial protein. Concentration-dependent decreases in plant ¹⁵N uptake occurred with increased leached nitrogen for LDPE microplastic. Assimilation into soil microbial protein was higher for biodegradable plastics, which we associate with early-stage biodegradable plastic degradation. Partitioning of ¹⁵N into inorganic soil N pools was affected by LDPE size, with lower assimilation into the microbial protein pool. While microplastics and macroplastics altered soil N cycling, the limited impacts on plant health indicated the threshold for negative effects was not reached at agriculturally relevant concentrations. This study highlights the difference between conventional and biodegradable plastics, and emphasises that the interplay of micro and macroplastics on soil N cycling must be considered in future studies.

Reprogramming of microbial community in barley root endosphere and rhizosphere soil by polystyrene plastics with different particle sizes

Polystyrene plastics is an emerging pollutant affecting plant performance and soil functioning. However, little information is available on the effects of microplastics and nanoplastics on plant root endophytic and rhizospheric soil microbial communities. Here, barley plants were grown in microplastics/nanoplastics -treated soil and the diversity, composition and function of bacteria and fungi in the root and rhizosphere soil were examined. At the seedling stage, greater changes of root endophytes were found compared with rhizosphere microorganisms under the plastic treatments. Nanoplastics decreased the richness and diversity of the fungal community, while microplastics increased the diversity of the root endophytic bacterial community. The network of the bacterial community under nanoplastics showed higher vulnerability while lower complexity than that under the control. However, the bacterial community under microplastics had a relatively higher resistance than the control. For the rhizosphere microbial community, no significant effect of plastics was found on the α-diversity index at the seedling stage. In addition, the nanoplastics resulted in higher sensitivity in the relative abundance and function of rhizosphere soil microbes than root endophytic microbes at the mature stage. Treatments of polystyrene plastics with different particle sizes reprogramed the rhizosphere and root endophytic microbial communities. Different effects of microplastics and nanoplastics were found on the diversity, composition, network structure and function of bacteria and fungi, which might be due to the variation in particle sizes. These results lay a foundation for learning the effects of polystyrene plastics with different particle sizes on the microorganisms in rhizosphere soil and plant roots, which may have important implications for the adaptation of plant-microbial holobiont in polystyrene plastics-polluted soils.

Visualizing Early Infection Sites of Rice Blast Disease (<em>Magnaporthe oryzae</em>) on Barley (<em>Hordeum vulgare)</em> Using a Basic Microscope and a Smartphone

Understanding how plants and pathogens interact, and whether that interaction culminates in defense or disease, is required to develop stronger and more sustainable strategies for plant health. Advances in methods that more effectively image plant-pathogen samples during infection and colonization have yielded tools such as the rice leaf sheath assay, which has been useful in monitoring infection and early colonization events between rice and the fungal pathogen, Magnaporthe oryzae. This hemi-biotrophic pathogen causes severe disease loss in rice and related monocots, including millet, rye, barley, and more recently, wheat. The leaf sheath assay, when performed correctly, yields an optically clear plant section, several layers thick, which allows researchers to perform live-cell imaging during pathogen attack or generate fixed samples stained for specific features. Detailed cellular investigations into the barley-M. oryzae interaction have lagged behind those of the rice host, in spite of the growing importance of this grain as a food source for animals and humans and as fermented beverages. Reported here is the development of a barley leaf sheath assay for intricate studies of M. oryzae interactions during the first 48 h post-inoculation. The leaf sheath assay, regardless of which species is being studied, is delicate; provided is a protocol that covers everything, from barley growth conditions and obtaining a leaf sheath, to inoculation, incubation, and imaging of the pathogen on plant leaves. This protocol can be optimized for high-throughput screening using something as simple as a smartphone for imaging purposes.

Impacts of recent climate change on crop yield can depend on local conditions in climatically diverse regions of Norway

Globally, climate change greatly impacts the production of major crops, and there have been many attempts to model future yields under warming scenarios in recent years. However, projections of future yields may not be generalisable to all crop growing regions, particularly those with diverse topography and bioclimates. In this study, we demonstrate this by evaluating the links between changes in temperature and precipitation and changes in wheat, barley, and potato yields at the county-level during 1980-2019 in Norway, a Nordic country with a range of climates across a relatively small spatial scale. The results show that the impacts of climate variables on yield vary widely by county, and that for some crops, the strength and direction of the link depends on underlying local bioclimate. In addition, our analysis demonstrates the need for some counties to focus on weather changes during specific crucial months corresponding with certain crop growth stages. Furthermore, due to the local climatic conditions and varying projected climate changes, different production opportunities are likely to occur in each county.

A molecular framework for grain number determination in barley

Flowering plants with indeterminate inflorescences often produce more floral structures than they require. We found that floral primordia initiations in barley (Hordeum vulgare L.) are molecularly decoupled from their maturation into grains. While initiation is dominated by flowering-time genes, floral growth is specified by light signaling, chloroplast, and vascular developmental programs orchestrated by barley CCT MOTIF FAMILY 4 (HvCMF4), which is expressed in the inflorescence vasculature. Consequently, mutations in HvCMF4 increase primordia death and pollination failure, mainly through reducing rachis greening and limiting plastidial energy supply to developing heterotrophic floral tissues. We propose that HvCMF4 is a sensory factor for light that acts in connection with the vascular-localized circadian clock to coordinate floral initiation and survival. Notably, stacking beneficial alleles for both primordia number and survival provides positive implications on grain production. Our findings provide insights into the molecular underpinnings of grain number determination in cereal crops.

Genetic engineering of complex feed enzymes into barley seed for direct utilization in animal feedstuff

Currently, feed enzymes are primarily obtained through fermentation of fungi, bacteria, and other microorganisms. Although the manufacturing technology for feed enzymes has evolved rapidly, the activities of these enzymes decline during the granulating process and the cost of application has increased over time. An alternative approach is the use of genetically modified plants containing complex feed enzymes for direct utilization in animal feedstuff. We co-expressed three commonly used feed enzymes (phytase, β-glucanase, and xylanase) in barley seeds using the Agrobacterium-mediated transformation method and generated a new barley germplasm. The results showed that these enzymes were stable and had no effect on the development of the seeds. Supplementation of the basal diet of laying hens with only 8% of enzyme-containing seeds decreased the quantities of indigestible carbohydrates, improved the availability of phosphorus, and reduced the impact of animal production on the environment to an extent similar to directly adding exogenous enzymes to the feed. Feeding enzyme-containing seeds to layers significantly increased the strength of the eggshell and the weight of the eggs by 10.0%-11.3% and 5.6%-7.7% respectively. The intestinal microbiota obtained from layers fed with enzyme-containing seeds was altered compared to controls and was dominated by Alispes and Rikenella. Therefore, the transgenic barley seeds produced in this study can be used as an ideal feedstuff for use in animal feed.

Unveiling of interactions between foliar-applied Cu nanoparticles and barley suffering from Cu deficiency

The objective of this study was to evaluate nano-Cu-plant interactions under Cu deficiency. Nano-Cu at rates of 100 and 1000 mg L^-1 was applied as foliar spray to Hordeum vulgare L. during increased demand for nutrients at tillering stage. Corresponding treatment with CuSO₄ was used to exam the nano-specific effects. Cu compounds-plant leaves interactions were analyzed with spectroscopic and microscopic methods (ICP-OES, FTIR/ATR, SEM-EDS). Moreover, the effect of Cu compounds on plants in terms of biomass, pigments content, lipid peroxidation, antiradical properties, the activity of enzymes involved in plant defense against stress (SOD, CAT, POD, GR, PAL, PPO) and the content of non-enzymatic antioxidants (GSH, GSSG, TPC) was determined after 1 and 7 days of exposure. Cu loading to plant leaves increased over time, but the content of Cu under treatment with nano-Cu at 100 mg L^-1 was lower by 76% than CuSO₄ at 7th day of exposure. The changes induced by applied Cu compounds in biochemical traits were mostly observed after 1 day. Our data showed that CuSO₄ exposure induce oxidative stress (increased MDA level and GSSG content) when compared to control and nano-Cu treated plants. Noteworthy, nano Cu at 100 mg L^-1 demonstrated enhanced stress tolerance as indicated by boosted GSH content. After 7 days, the antioxidant response was almost same compared to control sample. However, based on other indicators (pigment content, chlorosis sign, biomass), it should be noted that CuSO₄ caused serve oxidative burst of plant which may resulted in damage of defense system. Nano-Cu, especially at 100 mg L^-1, showed promising effect on plant health, and obtained results may be useful for optimizing of nano-Cu application as fertilizer agent.

Removing starch granule-associated surface lipids affects structure of heat-moisture treated hull-less barley starch

The effects of starch granule-associated surface lipids removal on hull-less barley starch structure formed by heat-moisture treatment were investigated. Removing surface lipids made the peak at 2θ of 13^° disappear and resulted in higher lamellar peak intensity after harsh treatment and a lower reduction in mass fractal dimension (from 2.49 to 2.43) and radius of gyration (from 24.3 to 24.0) when temperature increased from 100 to 120 °C at 20 % moisture. Treatment at 25 % moisture and 120 °C decreased relative crystallinity (from 15.73 % to 7.43 %) and Gaussian peak area (from 646.7 to 137.7) of native starch, and decreased relative crystallinity (from 14.24 % to 12.56 %) and Gaussian peak area (from 604.1 to 539.6) for starch without surface lipids. Different trends of change in lamellar thickness, linear crystallinity, peak temperatures, and enthalpy of gelatinization were observed among modified starches with increasing temperature and/or moisture content. These results demonstrate that removing surface lipids changes structure of heat-moisture treated starch.

Discrimination of Deoxynivalenol Levels of Barley Kernels Using Hyperspectral Imaging in Tandem with Optimized Convolutional Neural Network

Deoxynivalenol (DON) in raw and processed grain poses significant risks to human and animal health. In this study, the feasibility of classifying DON levels in different genetic lines of barley kernels was evaluated using hyperspectral imaging (HSI) (382-1030 nm) in tandem with an optimized convolutional neural network (CNN). Machine learning methods including logistic regression, support vector machine, stochastic gradient descent, K nearest neighbors, random forest, and CNN were respectively used to develop the classification models. Spectral preprocessing methods including wavelet transform and max-min normalization helped to enhance the performance of different models. A simplified CNN model showed better performance than other machine learning models. Competitive adaptive reweighted sampling (CARS) in combination with successive projections algorithm (SPA) was applied to select the best set of characteristic wavelengths. Based on seven wavelengths selected, the optimized CARS-SPA-CNN model distinguished barley grains with low levels of DON (<5 mg/kg) from those with higher levels (5 mg/kg < DON ≤ 14 mg/kg) with an accuracy of 89.41%. The lower levels of DON class I (0.19 mg/kg ≤ DON ≤ 1.25 mg/kg) and class II (1.25 mg/kg < DON ≤ 5 mg/kg) were successfully distinguished based on the optimized CNN model, yielding a precision of 89.81%. The results suggest that HSI in tandem with CNN has great potential for discrimination of DON levels of barley kernels.