Search Results (14)

Acyl-CoA-binding proteins (ACBPs) possess a conserved acyl-CoA-binding (ACB) domain that facilitates binding to acyl-CoA esters. In addition to their typical role in lipid metabolism, plant ACBPs have been shown to participate in various physiological processes, such as membrane biogenesis, stress response pathways and plant immunity mechanisms. Here, we identified five PutACBP members in alkaligrass (Puccinellia tenuiflora), which were divided into four distinct classes based on a phylogenetic tree constructed from 86 ACBP genes from 12 plant species. Promoter analysis identified numerous cis-acting elements linked to abiotic stresses (e.g., light, drought, heat, and cold) and hormone responses. Expression profile analyses revealed that PutACBPs exhibit broad expression patterns across many organs and respond to salinity-alkali, cold, H₂O₂, and CdCl₂ stresses. Transient expression of five PutACBP-GFPs in tobacco (Nicotiana tabacum) revealed PutACBP1 and PutACBP2 localized to the plasma membrane, cytoplasm, and cell nucleus, while PutACBP3, PutACBP4, and PutACBP5 localized around the plasma membrane and cytoplasm. Furthermore, heterologous constitutive expression of PutACBP3 in Arabidopsis (Arabidopsis thaliana) enhanced the resistance of transgenic plants to salinity stress, possibly through alterations in the levels of lipid metabolism-related and stress-responsive genes. The ACBP gene family is highly conserved across different plant species. This study provides the first comprehensive genomic and functional characterization of the PutACBP family in alkaligrass, elucidating its evolutionary conservation, phylogenetic classification, and stress-response roles. Notably, overexpression of PutACBP3 in Arabidopsis significantly enhanced salt tolerance, suggesting its critical function in salt-stress adaptation in alkaligrass. Full article

Global climate change is accelerating and human pressures are intensifying, exerting profound impacts on biodiversity and ecosystem service functions. The accurate prediction of species distributions has thus become a critical research direction in ecological conservation and restoration. This study selected Puccinellia tenuiflora, a species distributed across China, as its research subject. Utilizing 169 occurrence records and 10 environmental variables, we applied a parameter-optimized MaxEnt model to simulate the species’ current and future (2050s–2090s) potential suitable habitats under the SSP126, SSP370, and SSP585 scenarios. The results identified the human footprint index (HFI, 43.3%) and temperature seasonality (Bio4, 26.9%) as the dominant factors influencing its distribution. The current suitable area is primarily concentrated in northern China, covering approximately 258.26 × 10⁴ km². Under all future scenarios, a contraction of suitable habitat is projected, with the most significant reduction observed under SSP585 by the 2090s (a decrease of 56.2%). The distribution centroid is projected to shift northeastward by up to 145.36 km. This study elucidates the response mechanism of P. tenuiflora distribution to climate change and human activities. The projected habitat contraction and spatial displacement highlight the potential vulnerability of this species to future climate change. These findings, derived from a rigorously optimized and spatially validated model, provide a scientific basis for the conservation, reintroduction, and adaptive management of P. tenuiflora under climate change. Full article

The germin-like protein (GLP) family plays vital roles for plant growth, stress adaptation, and defense; however, its evolutionary dynamics and functional diversity in halophytes remain poorly characterized. Here, we present the genome-wide analysis of the GLP family in the halophytic forage alkaligrass (Puccinellia tenuiflora), which identified 54 PutGLPs with a significant expansion compared to other plant species. Phylogenetic analysis revealed monocot-specific clustering, with 41.5% of PutGLPs densely localized to chromosome 7, suggesting tandem duplication as a key driver of family expansion. Collinearity analysis confirmed evolutionary conservation with monocot GLPs. Integrated gene structure and motif analysis revealed conserved cupin domains (BoxB and BoxC). Promoter cis-acting elements analysis revealed stress-responsive architectures dominated by ABRE, STRE, and G-box motifs. Tissue-/organ-specific expression profiling identified root- and flower-enriched PutGLPs, implying specialized roles in stress adaptation. Dynamic expression patterns under salt-dominated stresses revealed distinct regulatory pathways governing ionic and alkaline stress responses. Functional characterization of PutGLP37 demonstrated its cell wall localization, dual superoxide dismutase (SOD) and oxalate oxidase (OXO) enzymatic activities, and salt stress tolerance in Escherichia coli, yeast (Saccharomyces cerevisiae INVSc1), and transgenic Arabidopsis. This study provides critical insights into the evolutionary innovation and stress adaptive roles of GLPs in halophytes. Full article

Salinity stress influences plants throughout their entire life cycle. However, little is known about the response of plants to long-term salinity stress (LSS). In this study, Puccinellia tenuiflora, a perennial halophyte grass, was exposed to 300 mM NaCl for two years (completely randomized experiment design with three biological replicates). We measured the photosynthetic parameters and plant hormones and employed a widely targeted metabolomics approach to quantify metabolites. Our results revealed that LSS induced significant metabolic changes in P. tenuiflora, inhibiting the accumulation of 11 organic acids in the leaves and 24 organic acids in the roots and enhancing the accumulation of 15 flavonoids in the leaves and 11 phenolamides in the roots. The elevated accumulation of the flavonoids and phenolamides increased the ability of P. tenuiflora to scavenge reactive oxygen species. A comparative analysis with short-term salinity stress revealed that the specific responses to long-term salinity stress (LSS) included enhanced flavonoid accumulation and reduced amino acid accumulation, which contributed to the adaptation of P. tenuiflora to LSS. LSS upregulated the levels of abscisic acid in the leaves and ACC (a direct precursor of ethylene) in the roots, while it downregulated the levels of cytokinins and jasmonic acids in both the organs. These tolerance-associated changes in plant hormones would be expected to reprogram the energy allocation among growth, pathogen defense, and salinity stress response. We propose that abscisic acid, ethylene, cytokinins, and jasmonic acids may interact with each other to construct a salinity stress response network during the adaptation of P. tenuiflora to LSS, which mediates salinity stress response and significant metabolic changes. Our results provided novel insights into the plant hormone-regulated metabolic response of the plants under LSS, which can enhance our understanding of plant salinity tolerance. Full article

The targeting of suitable mixed grass species and seeding rates of native grass seed in the process of ecological restoration in alpine mining areas is unclear. Four kinds of native grass seed (Poa pratensis cv. Qinghai, Poa crymophila cv. Qinghai, Puccinellia tenuiflora cv. Tongde and Pedicularis kansuensis) were selected as experimental materials to set up mixed sowing tests in the Muli mining area, which were analyzed for changes in plant coverage, biomass, forage nutrient composition, and soil physicochemical properties under different mixed grass species and seeding rates, aiming to provide a data reference and theoretical basis for the screening of suitable mixed grass species and seeding rates for artificial grassland planting in alpine mining areas. The results showed that the mixed grass species and seeding rate (HF) of Poa pratensis cv. Qinghai + Poa crymophila cv. Qinghai + Puccinellia tenuiflora cv. Tongde + Pedicularis kansuensis had the highest vegetation coverage (97.33%). At the same time, the aboveground biomass of HF was the largest (356.27 g·m⁻²). The soil organic matter, total nitrogen, total phosphorus, and total potassium of HF increased by 37.05%, 28.11%, 34.68%, and 10.14%, respectively, compared with CK, and the difference was significant (p < 0.05). Principal component analysis was carried out on 23 indexes of vegetation and soil. It was found that nine indexes, including coverage, aboveground biomass, belowground biomass, soluble sugar, and soil organic matter content, were the key indexes of evaluation. By sorting the membership functions of the above indicators, it was found that among the 12 mixed grass species and seeding rates, the comprehensive evaluation value of HF was the highest (0.848). In summary, it is recommended that the mixed grass species and seeding rate of Poa pratensis cv Qinghai + Poa crymophila cv. Qinghai + Puccinellia tenuiflora cv. Tongde + Pedicularis kansuensis be adopted for ecological restoration in alpine mining areas; this mixed grass species and seeding rate can effectively promote plant growth and development and improve the physicochemical properties of the soil, which can improve the stability and sustainability of the artificial grassland in the alpine mining area. Full article

The antioxidative enzyme ascorbate peroxidase (APX) exerts a critically important function through scavenging reactive oxygen species (ROS), alleviating oxidative damage in plants, and enhancing their tolerance to salinity. Here, we identified 28 CmAPX genes that display an uneven distribution pattern throughout the 12 chromosomes of the melon genome by carrying out a bioinformatics analysis. Phylogenetic analyses revealed that the CmAPX gene family comprised seven different clades, with each clade of genes exhibiting comparable motifs and structures. We cloned 28 CmAPX genes to infer their encoded protein sequences; we then compared these sequences with proteins encoded by rice APX proteins (OsAPX2), Puccinellia tenuiflora APX proteins (PutAPX) and with pea APX proteins. We found that the CmAPX17, CmAPX24, and CmAPX27 genes in Clade I were closely related, and their structures were highly conserved. CmAPX27 (MELO3C020719.2.1) was found to promote resistance to 150 mM NaCl salt stress, according to quantitative real-time fluorescence PCR. Transcriptome data revealed that CmAPX27 was differentially expressed among tissues, and the observed differences in expression were significant. Virus-induced gene silencing of CmAPX27 significantly decreased salinity tolerance, and CmAPX27 exhibited differential expression in the leaf, stem, and root tissues of melon plants. This finding demonstrates that CmAPX27 exerts a key function in melon’s tolerance to salt stress. Generally, CmAPX27 could be a target in molecular breeding efforts aimed at improving the salt tolerance of melon; further studies of CmAPX27 could unveil novel physiological mechanisms through which antioxidant enzymes mitigate the deleterious effects of ROS stress. Full article

In this study, we analyzed the C, N, and P contents and stoichiometric characteristics of forage leaves of five species (Elymus breviaristatus cv. Tongde, Poa crymophila cv. Qinghai, Puccinellia tenuiflora cv. Qinghai, Festuca sinensis cv. Qinghai, and Poa pratensis cv. Qinghai) in “fertilizer-reconstructed soil” through integrative soil amendment with parched sheep manure and granular organic fertilizer in an alpine mining area. A model is fitted in order to screen out the best forage species suitable for vegetation restoration in the alpine mining area and the most favorable fertilizer dosage to improve the nutrient content of forage leaves. The results showed that (1) increasing the dosages of granular organic fertilizer and sheep manure had little effect on the C content of the five types of forage grasses, but they could significantly increase the N and P contents and N/P of the manually restored grassland in the alpine mining area (p < 0.05). (2) The productivity and stability of the five species were ranked as follows: Elymus breviaristatus cv. Tongde > Puccinellia tenuiflora cv. Qinghai > Festuca sinensis cv. Qinghai > Poa pratensis cv. Qinghai > Poa crymophila cv. Qinghai. (3) According to the fitted least squares model and the willingness to maximize the C, N, and P contents of the leaves, the ranking of the five forage grasses was described by the Prediction Profiler as follows: Elymus breviaristatus cv. Tongde > Puccinellia tenuiflora cv. Qinghai > Festuca sinensis cv. Qinghai > Poa crymophila cv. Qinghai > Poa pratensis cv. Qinghai. (4) The predictive model suggested that the optimal contents of C, N, and P in Elymus breviaristatus cv. Tongde, Festuca sinensis cv. Qinghai, and Poa pratensis cv. Qinghai leaves could be achieved with the application of 3.6 kg/m² of granular organic fertilizer and 45.0 kg/m² of sheep manure. For Poa crymophila cv. Qinghai leaves, the ideal content was attained by applying 0 kg/m² of granular organic fertilizer and 45.0 kg/m² of sheep manure. Lastly, the optimal C, N, and P contents in Puccinellia tenuiflora cv. Qinghai leaves could be obtained through the application of 3.6 kg/m² of granular organic fertilizer combined with 0 kg/m² of sheep manure. In conclusion, the study’s results highlight the significant practical value of the fertilizer-reconstructed soil for vegetation restoration in alpine mining regions. Full article

Coexisting salt and alkaline stresses seriously threaten plant survival. Most studies have focused on halophytes; however, knowledge on how plants defend against saline–alkali stress is limited. This study investigated the role of Taraxacum mongolicum in a Puccinellia tenuiflora community under environmental saline–alkali stress to analyse the response of elements and metabolites in T. mongolicum, using P. tenuiflora as a control. The results show that the macroelements Ca and Mg are significantly accumulated in the aboveground parts (particularly in the stem) of T. mongolicum. Microelements B and Mo are also accumulated in T. mongolicum. Microelement B can adjust the transformation of sugars, and Mo contributes to the improvement in nitrogen metabolism. Furthermore, the metabolomic results demonstrate that T. mongolicum leads to decreased sugar accumulation and increased amounts of amino acids and organic acids to help plants resist saline–alkali stress. The resource allocation of carbon (sugar) and nitrogen (amino acids) results in the accumulation of only a few phenolic metabolites (i.e., petunidin, chlorogenic acid, and quercetin-3-O-rhamnoside) in T. mongolicum. These phenolic metabolites help to scavenge excess reactive oxygen species. Our study primarily helps in understanding the contribution of T. mongolicum in P. tenuiflora communities on coping with saline–alkali stress. Full article

Soil alkalization is a major environmental threat that affects plant distribution and yield in northeastern China. Puccinellia tenuiflora is an alkali-tolerant grass species that is used for salt-alkali grassland restoration. However, little is known about the molecular mechanisms by which arbuscular mycorrhizal fungi (AMF) enhance P. tenuiflora responses to alkali stress. Here, metabolite profiling in P. tenuiflora seedlings with or without arbuscular mycorrhizal fungi (AMF) under alkali stress was conducted using liquid chromatography combined with time-of-flight mass spectrometry (LC/TOF-MS). The results showed that AMF colonization increased seedling biomass under alkali stress. In addition, principal component analysis (PCA) and orthogonal projections to latent structures discriminant analysis (OPLS-DA) demonstrated that non-AM and AM seedlings showed different responses under alkali stress. A heat map analysis showed that the levels of 88 metabolites were significantly changed in non-AM seedlings, but those of only 31 metabolites were significantly changed in AM seedlings. Moreover, the levels of a total of 62 metabolites were significantly changed in P. tenuiflora seedlings after AMF inoculation. The results suggested that AMF inoculation significantly increased amino acid, organic acid, flavonoid and sterol contents to improve osmotic adjustment and maintain cell membrane stability under alkali stress. P. tenuiflora seedlings after AMF inoculation produced more plant hormones (salicylic acid and abscisic acid) than the non-AM seedlings, probably to enhance the antioxidant system and facilitate ion balance under stress conditions. In conclusion, these findings provide new insights into the metabolic mechanisms of P. tenuiflora seedlings with arbuscular mycorrhizal fungi under alkali conditions and clarify the role of AM in the molecular regulation of this species under alkali stress. Full article

The depth distribution of soil organic carbon (SOC) in a soil profile is important to examine the effects of different treatments on SOC sequestration. This study was conducted to determine the effects of different vegetation types on the concentration, storage, and stratification ratio (SR) of SOC in northeastern China. Five vegetation types, Leymus chinensis (LEY), Puccinellia tenuiflora (PUC), Echinochloa phyllopogon (ECH), saline seepweed (SUA), and Chloris virgata Swartz (CHL), were selected as treatments. Soil bulk density and SOC concentration were measured at 0 to 50 cm depth, and SOC storage and four SRs (SR1 [0–10:10–20 cm], SR2 [0–10:20–30 cm], SR3 [0–10:30–40 cm], and SR4 [0–10:40–50 cm]) were calculated under the five vegetation types. Results showed a pronounced reduction in SOC concentration with increasing soil depth. Vegetation types had significant effects on SOC concentration and storage. Under PUC, ECH, SUA, and CHL treatments, SOC concentrations (2.150, 1.068, 4.110, and 2.542 g kg⁻¹, respectively) and storages (15.075, 7.273, 30.024, and 18.078 Mg ha⁻¹, respectively) at 0–50 cm depth were lower than those under the LEY treatment. SR1 values were all < 2, while SR2, SR3, and SR4 values were all > 2 except for SR2 under ECH and SUA treatments. Vegetation types had significant effects on SR3 (p < 0.001) and SR4 (p = 0.040), while no significant differences were found for SR1 and SR2 due to the narrow range, with values of 0.248 and 0.553 for SR1 and SR2, respectively, among the vegetation types. These results indicated that the degraded soils have great potential to sequester organic carbon in northeastern China, and SR3 could be used as an effective index to show the changes in SOC concentration and soil quality in northeastern China. Full article

Rubredoxin is one of the simplest iron–sulfur (Fe–S) proteins. It is found primarily in strict anaerobic bacteria and acts as a mediator of electron transfer participation in different biochemical reactions. The PutRUB gene encoding a chloroplast-localized rubredoxin family protein was screened from a yeast full-length cDNA library of Puccinellia tenuiflora under NaCl and NaHCO₃ stress. We found that PutRUB expression was induced by abiotic stresses such as NaCl, NaHCO₃, CuCl₂ and H₂O₂. These findings suggested that PutRUB might be involved in plant responses to adversity. In order to study the function of this gene, we analyzed the phenotypic and physiological characteristics of PutRUB transgenic plants treated with NaCl and NaHCO₃. The results showed that PutRUB overexpression inhibited H₂O₂ accumulation, and enhanced transgenic plant adaptability to NaCl and NaHCO₃ stresses. This indicated PutRUB might be involved in maintaining normal electron transfer to reduce reactive oxygen species (ROS) accumulation. Full article

Puccinellia tenuiflora is an alkaline salt-tolerant monocot found in saline-alkali soil in China. To identify the genes which are determining the higher tolerance of P. tenuiflora compared to bicarbonate sensitive species, we examined the responses of P. tenuiflora and a related bicarbonate-sensitive Poeae plant, Poa annua, to two days of 20 mM NaHCO₃ stress by RNA-seq analysis. We obtained 28 and 38 million reads for P. tenuiflora and P. annua, respectively. For each species, the reads of both unstressed and stressed samples were combined for de novo assembly of contigs. We obtained 77,329 contigs for P. tenuiflora and 115,335 contigs for P. annua. NaHCO₃ stress resulted in greater than two-fold absolute expression value changes in 157 of the P. tenuiflora contigs and 1090 of P. annua contigs. Homologs of the genes involved in Fe acquisition, which are important for the survival of plants under alkaline stress, were up-regulated in P. tenuiflora and down-regulated in P. annua. The smaller number of the genes differentially regulated in P. tenuiflora suggests that the genes regulating bicarbonate tolerance are constitutively expressed in P. tenuiflora. Full article

Puccinellia tenuiflora is a monocotyledonous halophyte that is able to survive in extreme saline soil environments at an alkaline pH range of 9–10. In this study, we transformed full-length cDNAs of P. tenuiflora into Saccharomyces cerevisiae by using the full-length cDNA over-expressing gene-hunting system to identify novel salt-tolerance genes. In all, 32 yeast clones overexpressing P. tenuiflora cDNA were obtained by screening under NaCl stress conditions; of these, 31 clones showed stronger tolerance to NaCl and were amplified using polymerase chain reaction (PCR) and sequenced. Four novel genes encoding proteins with unknown function were identified; these genes had no homology with genes from higher plants. Of the four isolated genes, two that encoded proteins with two transmembrane domains showed the strongest resistance to 1.3 M NaCl. RT-PCR and northern blot analysis of P. tenuiflora cultured cells confirmed the endogenous NaCl-induced expression of the two proteins. Both of the proteins conferred better tolerance in yeasts to high salt, alkaline and osmotic conditions, some heavy metals and H₂O₂ stress. Thus, we inferred that the two novel proteins might alleviate oxidative and other stresses in P. tenuiflora. Full article

Soil salt-alkalinization is a widespread environmental stress that limits crop growth and agricultural productivity. The influence of soil alkalization caused by Na₂CO₃ on plants is more severe than that of soil salinization. Plants have evolved some unique mechanisms to cope with alkali stress; however, the plant alkaline-responsive signaling and molecular pathways are still unknown. In the present study, Na₂CO₃ responsive characteristics in leaves from 50-day-old seedlings of halophyte Puccinellia tenuiflora were investigated using physiological and proteomic approaches. Comparative proteomics revealed 43 differentially expressed proteins in P. tenuiflora leaves in response to Na₂CO₃ treatment for seven days. These proteins were mainly involved in photosynthesis, stress and defense, carbohydrate/energy metabolism, protein metabolism, signaling, membrane and transport. By integrating the changes of photosynthesis, ion contents, and stress-related enzyme activities, some unique Na₂CO₃ responsive mechanisms have been discovered in P. tenuiflora. This study provides new molecular information toward improving the alkali tolerance of cereals. Full article