Hordeum Brevisubulatum Research Articles

Regulation of mineral elements in Hordeum brevisubulatum by Epichloë bromicola under Cd stress

In this study, wild barley (Hordeum brevisubulatum) infected (E+) and uninfected (E-) by Epichloë bromicola were used for hydroponic experiments during the seedling stage. Various attributes, such as the effect of fungal endophyte on the growth and development of wild barley, the absorption of cadmium (Cd) and mineral elements (Ca, Mg, Fe, Mn, Cu, Zn), subcellular distribution, and chemical forms were investigated under CdCl2 stress. The results showed that the fungal endophy significantly reduced the Ca content and percentage of plant roots under Cd stress. The Fe and Mn content of roots, the mineral element content of soluble fractions, and the stems in the pectin acid or protein-chelated state increased significantly in response to fungal endophy. Epichloë endophyte helped Cd2+ to enter into plants; and reduced the positive correlation of Ca-Fe and Ca-Mn in roots. In addition, it also decreased the correlation of soluble components Cd-Cu, Cd-Ca, Cd-Mg in roots, and the negative correlation between pectin acid or protein-chelated Cd in stems and mineral elements, to increase the absorbance of host for mineral elements. In conclusion, fungal endophy regulated the concentration and distribution of mineral elements, while storing more Cd2+ to resist the damage caused by Cd stress. The study could provide a ground for revealing the Cd tolerance mechanism of endophytic fungal symbionts.

Influence of the aftereffect of mineral fertilizers on the productivity of a long-term phytocenosis in the conditions of the Privilyui agrolandscape of the middle taiga subzone of Yakutia

The article provides the research of 2011-2019 on studying the long-term influence of the aftereffect of 36-year application of mineral fertilizers on the productivity and nutritional value of long-term meadow phytocenoses. In a stationary experiment with a radical improvement of meadows, the following variants for applying mineral fertilizers were studied from 1974 to 2010: the minimum level was N62P60K11 (control), the average level was N202P175K43, and the maximum level was N318P362K189. In the conditions of the Privilyui agrolandscape of the middle taiga subzone of Yakutia, a long-term aftereffect of fertilizers (from 2011 to 2019) contributed to the preservation of the main dominant in the grass stand - couch grass (Elymus repens (L.) Nevski) up to 27.4-42.1 % and codominant – short-awned barley (Hordeum brevisubulatum (Trin) Link.) up to 14.7-24.3 %. During the aftereffect of fertilizers, the yield of cereal-forb phytocenosis averaged 1.71-2.03 t/ha of hay, which is 2.1-2.5 times higher than the yield of natural meadows. At the same time, hay forage contained up to 8.9-9.1 MJ of exchange energy, up to 0.62-0.65 feed units, and up to 80-90 g of digestible protein, which corresponds to the zootechnical norm.

Epichloë bromicola from wild barley improves salt-tolerance of cultivated barley by altering physiological responses to salt stress.

Epichloë bromicola is a cultivable fungal endophyte that lives in symbiosis with wild barley (Hordeum brevisubulatum) to which it confers salt tolerance. This study tested the hypothesis that E. bromicola derived from wild barley has the potential to increase salt tolerance in cultivated barley under salt stress. To test this hypothesis, the growth response, physiological parameters, and metabolic profiles of barley plants inoculated with E. bromicola (E+) and those not inoculated with E. bromicola (E-) were compared under salt stress. Compared with E- barley plants, E+ barley plants had significantly increased plant height, shoot biomass, total biomass, chlorophyll content, osmotic synthesis, and accumulation of stress adaptation metabolites. E. bromicola increased the salt stress tolerance of cultivated barley, and the positive effects correlated with different salt stress conditions. These results suggest that E. bromicola has promising potential for enhancing the salt tolerance of barley. New insights into the mechanisms underlying this barley-fungal endophyte association are provided, and interesting questions regarding the role of E. bromicola in fungus-enhanced tolerance to salt stress in this symbiosis are raised.

A Novel Transcriptional Regulator HbERF6 Regulates the HbCIPK2-Coordinated Pathway Conferring Salt Tolerance in Halophytic Hordeum brevisubulatum.

Halophytic Hordeum brevisubulatum is a perennial grass which has evolved many distinctive salt-adaptive mechanisms. Our previous studies indicated it could thrive under salt stress through maintaining better K+ and Na+ homeostasis. Stress-responsive HbCIPK2 can phosphorylate K+ channel HbVGKC1 and Na+ transporter HbSOS1L to prevent Na+ accumulation and K+ reduction, hence pathway was not detected in glycophytic plants. In this study, we cloned the inducible promoter of HbCIPK2 by genome-walking, and identified a novel transcriptional regulator HbERF6 through yeast one-hybrid screening. HbERF6 functioned as a transcription factor which can bind to the GCC-box of the HbCIPK2 promoter to activate its expression. HbERF6 transgenic lines in Arabidopsis improved salt tolerance compared with wild type, and especially induced AtCIPK24 (SOS2) expression, resulting in K+/Na+ homeostasis to enhance salt tolerance. All the results confirmed the inducible function of HbERF6 for CIPK genes during salt tolerance. This regulatory network that integrates transcriptional regulation and post-translation modification will unravel a novel salt stress-responsive mechanism, highlighting the value and utilization of the halophytic resource.

Effect of Fungal Endophyte Epichloë bromicola Infection on Cd Tolerance in Wild Barley (Hordeum brevisubulatum).

Hydroponic Hordeum brevisubulatum (wild barley) was used as material in the greenhouse to study the effects of endophyte infection on plant growth, Cd absorption and transport, subcellular distribution, and Cd chemical forms under CdCl2 stress. Endophytic fungi respond positively to chlorophyll content and photosynthetic efficiency under Cd stress. The order of Cd absorption in different parts of the plant was: roots > stems > leaves. Endophyte infection increased the plant’s absorption and transport of Cd while causing a significant difference in the stem, which was associated with the distribution density of endophyte hyphae. The proportion of organelle Cd in endophyte-infected wild barley was significantly higher, which facilitated more Cd transport to aboveground. Cd stress showed a slight effect on the chemical forms of Cd in leaves. The proportion of phosphate, oxalate, and residual Cd increased in the stem. Cd existed in the form of inorganic salt, organic acid, pectin, and protein in roots. Endophyte infection reduced the Cd content of the more toxic chemical forms to protect the normal progress of plant physiological functions. Therefore, the isolation of cell walls and vacuoles is a key mechanism for plant Cd tolerance and detoxification. As endophyte infections have more ability to absorb Cd in plants, H. brevisubulatum–Epichloë bromicola symbionts can improve heavy metal contaminated soil and water.

Inoculation of Barley (Hordeum vulgare) with the Endophyte Epichloë bromicola Affects Plant Growth, and the Microbial Community in Roots and Rhizosphere Soil.

Hordeum vulgare is an important source of feed and forage for livestock, and of food and drink for humans, but its utilization rate is lower than that of other cereal crops, thus it is crucial to improve barley agronomic traits and production. Epichloë bromicola is an endophyte that was isolated from wild barley (Hordeum brevisubulatum). Previous studies have found that Epichloë can indirectly influence the growth of host plants by affecting soil chemical characteristics, the microbial community, and by producing a range of secondary metabolites. However, underlying effects of Epichloë on the abundance and diversity of soil and root microbes have not been well-studied. In addition, there is a question regarding the relationship between endophyte-produced alkaloids and effects on the root and rhizosphere microbial communities. The objective of this study was to investigate changes in agronomic traits, nutritional properties, peramine, soil chemical and microbial community in the fourth generation of new barley symbionts EI (E. bromicola-infection) and EF (E. bromicola-free) in LQ+4 and LZ+4. We understand the plant height and biomass of EI in LZ+4 were significantly higher than those of EF. The HPLC analysis showed that the peramine content of EI in LQ+4 and LZ+4 was 0.085 and 0.1 mg/g, respectively. We compared the bacterial and fungal communities by analyzing the 16s rRNA (for bacteria) and ITS rDNA regions (for fungi). Our data revealed that the composition of fungal communities in rhizosphere soil of LZ+4 EI are higher than EF. In addition, the diversity and richness of fungal communities in root and rhizosphere soil of LQ+4 EI and LZ+4 EI are significantly higher than EF. Rhizosphere soil microbial community composition was higher than that in roots in LQ+4 and LZ+4. Peramine was significantly and positively correlated with the richness of the soil fungal community. Moreover, the principal component analysis (PCoA) results indicated that E. bromicola significantly influenced the community composition of root and rhizosphere soil microbes in both LQ+4 and LZ+4. Our results illustrate that E. bromicola can influence barley growth, peramine production and microbial communities associated with barley.

Regulation of Mineral Elements in Hordeum Brevisubulatum by Epichloë Bromicola Under Cd Stress

Regulation of Mineral Elements in Hordeum Brevisubulatum by Epichloë Bromicola Under Cd Stress

NaCl stress modifies the concentrations of endophytic fungal hyphal and peramine in

Context Infecting grasses with an Epichloë endophyte contribute significantly to host plant salt tolerance. The Epichloë endophyte alkaloid peramine is primarily responsible for feeding deterrence against some herbivorous insects. Infection by an Epichloë is required for peramine production in the host grass. Limited information is available regarding the effects of salinity stress on Epichloë endophyte colonisation and associated production of peramine metabolites. Aims and methods In this study, we determined the effects of NaCl stress on the concentration of endophytic hyphae and peramine in wild barley (Hordeum brevisubulatum (Trin.) Link) seedlings infected with Epichloë bromicola. Key results Seedings dry weight at 4 weeks declined from 7.05 to 4.27 g/plant over the range, 0–300 mM NaCl. The hyphal concentration, as well as the peramine concentration, increased in response to high NaCl concentrations, hyphae and peramine concentration at 4 weeks increased from 13.29 to 264.60 copies/ng gDNA and from 26.75 to 43.19 μg/g DW, respectively. Peramine concentration was positively correlated with the concentration of hyphae (R2 = 0.4012, P < 0.001). Conclusions and implications It seems that peramine concentration was mostly explained by the in-planta variation in endophyte hyphae concentration in wild barley infected with Epichloë species under highly saline conditions.

Soil microbial and chemical responses to foliar Epichloë fungal infection in Lolium perenne, Hordeum brevisubulatum and Achnatherum inebrians

We tested whether the host species identity in grass- Epichloë symbioses affected soil chemical and microbial properties. We grew endophyte infected (E+) and endophyte free (E−) Lolium perenne , Hordeum brevisubulatum and Achnatherum inebrians for 18 months in field plots. In E+ soil of all three grasses, available phosphorus was lower whereas total soil nitrogen was higher. Endophyte effects on soil pH, microbial biomass nitrogen, total carbon and organic carbon as well as bacteria and fungi abundance were host species dependent. Ammonia oxidizing bacteria abundance was higher in E+ soils for all species. Bacterial community composition of E+ and E− soils were different only for Lolium perenne with soil pH being the key factor. Fungal community composition of E+ and E− soils was not different for the three grasses. This study confirmed that the effects of foliar Epichloë infection on belowground properties depended on host species identity. • Foliar Epichloë infection (E+) affected soil properties differently between hosts. • Soil available phosphorous was higher in foliar Epichloë infection free (E−) soils. • Total nitrogen and ammonia oxidizing bacteria abundance were higher in E+ soils. • Bacterial diversity differed between E+ and E− perennial ryegrass soils. • Soil pH contributed the most to bacterial diversity variation.

Tactics and life strategies of cenopopulation Hordeum brevisubulatum (Trin.) Link

Survival tactics and strategy of Hordeum brevisubulatum the dominant of meadow phytocenoses in CentralYakutia were studied. Traits-indicators annually change ontogenetic tactics, except for the taxonomic trait-indicator.Protective-stress and stress-protective ontogenetic strategy and CS type of ecological-coenotic strategin were established.

Influence of Interactions between Nitrogen, Phosphorus Supply and Epichloёbromicola on Growth of Wild Barley (Hordeum brevisubulatum).

Epichloë endophytes are biotrophic fungi that establish mutualistic symbiotic relationship with grasses and affect performance of the host under different environments. Wild barley (Hordeum brevisubulatum) is an important forage grass and often infected by Epichloë bromicola, thus showing tolerances to stresses. Since the plant growth correlates with both microbial infection and nutrient stoichiometry, this study was performed to investigate whether the function of Epichloë bromicola endophyte to improve host growth depend upon the nitrogen (N), phosphorus (P) fertilization. Epichloë-infected (E+) and Epichloë-free (E−) wild barley plants were subjected to nine types of mixed N (0.2 mM, 3 mM, 15 mM) and P (0.01 mM, 0.1 mM, 1.5 mM) levels treatments for 90 d to collect plant samples and determine multiple related indexes. We found that E. bromicola and N, P additions positively affected seed germination. Further, E. bromicola significantly enhanced chlorophyll content and root metabolic activity under N-deficiency, and meanwhile, might alter allocation of photosynthate under different conditions. The contents of N, P and stoichiometry of C:N:P of E+ plants were significantly higher than that of E− under nutrient deficiency, but contrary results were observed under adequate nutrients. Therefore, we propose that the growth-promoting ability of E. bromicola is closely correlated with N and P additional levels. Under low N, P additions, positive roles of endophyte are significant as opposed to negative roles under high N, P additions.

Determination of Yield and Botanical Composition of the Meadow and Grassland in Çolpan Village at the Shores of Lake Van

This study was carried out at the meadows and pastures in Çolpan village of Van province in 2020. In the study, matter yield, botanical composition, plant covered area, rate of decreaser/increaser/invader species were determined. The Loop method was used to determine the botanical composition. In grassland area were identified 69 species belonging to 17 families. In meadow area were identified 20 species belonging to 6 families. The amount of Poaceae, Fabaceae and other families found in the grassland area were determined as 18.66%, 15.65%, and 65.69%, respectively. In the meadow area, the amount of Poaceae, Fabaceae and other families were determined as 67.50%, 15.0%, and 17.50%, respectively. Artemisia spicigera (4.74%) Taeniatherum caput-medusae (5.0%) Arenaria serpyllifolia (5.0%) Medicago monantha (5.92%) species were the most common species found in the grassland area. Hordeum brevisubulatum (25.5%), Bromus scoparius (16.75%), and Taraxacum androssovii (9.25%) species were the most common species found in the meadow area. According to the ratio of good plants, pasture was classified as poor pasture and meadow was in the moderate meadow class. Grassland and meadow matter yields were found to be 91.4 kg/da and 385.2 kg/da, respectively. In the grassland of Çolpan village, invader species were found to be dense. It was concluded that grassland area should be improved.

Fungal endophyte Epichloë bromicola infection regulates anatomical changes to account for salt stress tolerance in wild barley (Hordeum brevisubulatum)

Plants can minimize the adverse effects of salinity by modifying morphological and anatomical features. Previous studies showed that endophytic Epichloe bromicola play an important role in improving wild barley (Hordeum brevisubulatum) salinity tolerance. The aim of this work is to understand whether Epichloe endophyte affects the anatomical structures of host H. brevisubulatum under salinity environments. Seedlings of E. bromicola infected (E+) and E. bromicola free (E-) H. brevisubulatum were treated with different NaCl concentrations, with the control seedlings being grown without NaCl. Anatomical structures of roots, stems and leaves were observed by making paraffin sections with double staining dehydration methods (safranin and fast green). NaCl treatments significantly affected the anatomical structure of H. brevisubulatum. Vascular tissue area throughout the leaf, stem and root decreased as the NaCl concentration increased. Thickness of epidermis in stems and leaves, and the cortex in roots also decreased with salt level increases. Endodermis thickness, epidermis thickness and stele area in roots were increased under salinity stress. The presence of Epichloe endophyte regulated some anatomical structure modifications. Epichloe infection was associated with significant higher conducting tissues (including leaf xylem, leaf phloem, stem vascular bundles, stem xylem vessels and root meta-xylem area). The increased thickness of leaf veins, epidermis in stems, cortex and endodermis in roots were also associated with Epichloe endophyte infection under NaCl stress. The presence of Epichloe endophyte ameliorated adverse effects of salinity on H. brevisubulatum. We observed specific changes of anatomical structures that may help in inhibiting water loss and inhibiting decrease of transport capacity for better conduction of water, nutrients, photosynthates and re-translocation of assimilates to suppress negative effects of salinity and enhance the tolerance of H. brevisubulatum to salt stress.

Creation of novel barley germplasm usingan <italic>Epichloë</italic> endophyte

Plant-endophyte associations play important roles in grassland agricultural ecology. Many studies indicate that endophytic fungi can promote host growth and reduce the biotic and abiotic stresses of host plants. Epichloe endophytes of the family Clavicitaceae are fungal symbionts of Pooideae grasses. These endophytes usually do not express any obvious host symptoms. Many Epichloe endophytes can endow hosts with increased abiotic stress tolerance as a result of enhanced growth, tillering, reproduction and nutrient acquisition, particularly under conditions of drought, cold, salt and nutrient deficiencies and thus, have important roles in pastoral agricultural systems. Animal-safe grass-endophyte associations that confer bio-protective properties for increased pasture persistence and productivity have been developed and commercialized. Artificial inoculation with symbiotic Epichloe microbes is an important technique for the creation of novel germplasm. Selected Epichloe strains can add value to some grass-based forage systems by providing both biotic and abiotic stress resistance. In addition, they can improve and strengthen grass physiological functions and plant vigor. The Epichloe bromicola WBE1 endophyte of Hordeum brevisubulatum played an important role in maintaining the growth of host grass by promoting nutrient absorption and maintaining the ionic balance under salt stress. E. bromicola WBE1 can produce peramine, an alkaloid produced by Epichloe species, that protects host grasses from herbivorous insects. However, this strain was unable to synthesize the alkaloids that are toxic to livestock, such as ergine, ergonovine, ergovaline or lolitrem B. Barley ( Hordeum vulgare ) is one of the most important cereal crops. The importance of barley to human and animal nutrition, and indeed to the foundation and maintenance of human civilization, is well documented. Traditional barley breeding for improved environmental stress tolerance has resulted in good varieties. However, conventional breeding techniques neglect the microorganisms in plants. In this study, animal-safe endophytic E. bromicola WBE1 isolated from wild barley ( H. brevisubulatum ) was artificially inoculated into cultivated hulled barley ( H. vulgare cv. Yangsimai No. 1) and hull-less barley ( H. vulgare var. nudum cv. Chaiqing No. 1), creating novel barley germplasm. Plants that were inoculated with endophytes and those that were free of endophytes were evaluated for growth in the field. The plant height, tiller numbers, biomass and the grain weight per plant of endophyte-inoculated hulled barley plants (Yangsimai No. 1) were 5%, 20%, 46% and 22% higher than those of the control hulled barley plants, respectively, and they matured about 5 days earlier. The tiller numbers, biomass and grain weight per plant of endophyte-inoculated hull-less barley plants (Chaiqing No. 1) were 29%, 37% and 28% higher, respectively, than those of the control hull-less barley plants in the field. However, there was no significant difference between inoculated hull-less barley plants and control hull-less barley plants in the plant height and growth period. A novel germplasm of barley containing the endophyte was successfully created. E. bromicola improves plant characteristics and the growth of host. The results presented here provide evidence that the inoculation of barley with E. bromicola may be used to improve its germplasm. E. bromicola can be successfully inoculated into other phylogenetically close host species, and this technique has the potential to improve the growth of Hordeae cereal crops and serve as a broad application to produce agriculturally useful synthetic novel symbioses in germplasm.

Effects of exogenous nitric oxide on wild barley (Hordeum brevisubulatum) under salt stress

Soil salinization has become more and more serious. Exogenous nitric oxide (NO) could act in alleviating toxicity in plants. In this study, we aimed to explore the growth, photosynthetic pigments, water-solubles content, proteins, antioxidant enzyme parameters, and element contents of two types of wild barley (Hordeum brevisubulatum (Trin.) Link.), wild-type barley and Saertu wild barley cultivars, in response to salt stress. Both cultivars were first treated with 300 µmol·L −1 NaCl (increased in 25 µmol·L −1 increments to 300 µmol·L −1 for 7 days). Next, plants were sprayed with different NO concentrations on days 1, 5, 10, 15 and 20 after the NaCl concentration reached 300 µmol·L −1. The results showed that salt stress alone decreased all growth parameters [plant height (HT), fresh weight (FW), total dry weight (DW)], the photosynthetic pigment and protein contents, and the activity of the antioxidant enzymes [ascorbic acid peroxidase (APX), peroxidase (POD), catalase (CAT), superoxide dismutase (SOD)], and significantly increased the K+ and Na+ elements contents, water solubles and malondialdehyde (MDA) compared with the controls. However, the inhibitory effects of salt stress in both wild barley cultivars were alleviated by exogenous NO treatment, and 200 µmol·L −1 NO was the most effective concentration to improve plant growth, ion element levels and the physiology of wild barley under high salt stress. Altogether, this study demonstrated the beneficial role of exogenous NO donor, sodium nitroprusside, on wild barley under salinity stress and the underlying physiological and biochemical mechanisms.

The structure of the features variability of Hordeum brevisubulatum Trin. (Link) in the middle Lena valley

The structure of variability of morphological features of perennial grass Hordeum brevisubulatum (Trin.)Link has been studied. The biological and ecological features-indicators defining the vitality state of individual andcoenopopulations of species were determined. Biological indicators are the length of the leaf sheath of the third and fourthleaves of the generative shoot and the signs of the generative sphere (inflorescence length, number of nodes and spikeletsin the inflorescence and potential seed productivity). The group of ecological features-indicators includes the number ofdifferent types of shoots in an individual.

Halophytic Hordeum brevisubulatum HbHAK1 Facilitates Potassium Retention and Contributes to Salt Tolerance.

Potassium retention under saline conditions has emerged as an important determinant for salt tolerance in plants. Halophytic Hordeum brevisubulatum evolves better strategies to retain K+ to improve high-salt tolerance. Hence, uncovering K+-efficient uptake under salt stress is vital for understanding K+ homeostasis. HAK/KUP/KT transporters play important roles in promoting K+ uptake during multiple stresses. Here, we obtained nine salt-induced HAK/KUP/KT members in H. brevisubulatum with different expression patterns compared with H. vulgare through transcriptomic analysis. One member HbHAK1 showed high-affinity K+ transporter activity in athak5 to cope with low-K+ or salt stresses. The expression of HbHAK1 in yeast Cy162 strains exhibited strong activities in K+ uptake under extremely low external K+ conditions and reducing Na+ toxicity to maintain the survival of yeast cells under high-salt-stress. Comparing with the sequence of barley HvHAK1, we found that C170 and R342 in a conserved domain played pivotal roles in K+ selectivity under extremely low-K+ conditions (10 μM) and that A13 was responsible for the salt tolerance. Our findings revealed the mechanism of HbHAK1 for K+ accumulation and the significant natural adaptive sites for HAK1 activity, highlighting the potential value for crops to promote K+-uptake under stresses.

The complete chloroplast genome of Hordeum brevisubulatum

In this study, the complete chloroplast genome of Hordeum brevisubulatum was sequenced and analyzed. The complete chloroplast genome of Hordeum brevisubulatum was 137,019 bp in length, encoding a total of 134 genes, including 87 protein-coding genes, 39tRNAs, and 8 rRNAs, with a CG content of 38.27%. The phylogenetic analysis of Hordeum brevisubulatum was carried out to determine the position of Gramineae in the phylogenetic evolution.

The Compensatory Tillering in the Forage Grass Hordeum brevisubulatum After Simulated Grazing of Different Severity.

The response of compensatory growth is an important adaptive strategy for plants to grazing. However, most previous studies on compensatory growth of plants focused on the compensation of the biomass or the number of sexual reproductive offspring and neglected the compensatory growth of vegetative reproduction (VR). This is important not only for plant compensatory growth studies, but also for theoretical and practical studies of grassland production. The clonal tussock grass Hordeum brevisubulatum was selected as the research object. Four different clipping severities (unclipping and clipping stubble at heights of 15, 10, and 5 cm) at the jointing stage and flowering stage were implemented to study the effect of simulated grazing. To explore the effect of recovery growth time on plant growth after simulated grazing, three sampling times were used at different recovery times after simulated grazing (1, 3, and 7 weeks). We found that light and moderate grazing severity significantly increased the number of vegetative reproduction modules, the promotion of simulated grazing on the number of vegetative reproduction modules was higher in the jointing stage than the flowering stage, and the increase in simulated grazing severity decreased with prolonged recovery growth time. The number of tillers significantly decreased with the increase in simulated grazing in both the jointing and flowering stages at 1 week after damage, and the decreasing effect weakened with the prolonged recovery growth time. The bud number mainly showed over-compensation, the juvenile tiller number showed complete compensation, and the tiller number showed under-compensation at 1 and 3 weeks after recovery growth. The number of tillers showed complete compensation under different grazing severities in the jointing stage, while it showed under-compensation in the flowering stage at 7 weeks after recovery growth. Our results indicated that different grazing severities in the jointing stage could promote the output of tillers with matter production capacity from vegetative reproduction modules, as well as improve the capability of compensatory growth. Therefore, in plant production, there will be a sustainable development effect on the renewal and productivity of the H. brevisubulatum population, resulting in different grazing severities in the jointing stage.

Emerging crosstalk between two signaling pathways coordinates K+ and Na+ homeostasis in the halophyte Hordeum brevisubulatum.

K+/Na+ homeostasis is the primary core response for plant to tolerate salinity. Halophytes have evolved novel regulatory mechanisms to maintain a suitable K+/Na+ ratio during long-term adaptation. The wild halophyte Hordeum brevisubulatum can adopt efficient strategies to achieve synergistic levels of K+ and Na+ under high salt stress. However, little is known about its molecular mechanism. Our previous study indicated that HbCIPK2 contributed to prevention of Na+ accumulation and K+ reduction. Here, we further identified the HbCIPK2-interacting proteins including upstream Ca2+ sensors, HbCBL1, HbCBL4, and HbCBL10, and downstream phosphorylated targets, the voltage-gated K+ channel HbVGKC1 and SOS1-like transporter HbSOS1L. HbCBL1 combined with HbCIPK2 could activate HbVGKC1 to absorb K+, while the HbCBL4/10-HbCIPK2 complex modulated HbSOS1L to exclude Na+. This discovery suggested that crosstalk between the sodium response and the potassium uptake signaling pathways indeed exists for HbCIPK2 as the signal hub, and paved the way for understanding the novel mechanism of K+/Na+ homeostasis which has evolved in the halophytic grass.