Search Results (13)

The cigarette butt (CB) recycling process yields several byproducts, including cleaned filters, solid debris (mainly paper and tobacco), and wastewater. This study aimed to assess, for the first time, the long-term suitability of these recycled byproducts for turfgrass cultivation. Under controlled conditions, Paspalum vaginatum Swartz was grown in sand–peat substrate, either unmodified (control) or amended with small pieces of uncleaned CBs or solid byproducts from CB recycling at concentrations of 25% or 50% (v/v). In additional tests, turfgrass grown in unmodified substrate received wastewater instead of tap water once or twice weekly. Over 7 weeks, physiological and biometric parameters were assessed. Plants grown with solid debris showed traits comparable to the control. Those grown with intact CBs or cleaned filters had similar biomass and coverage as the control but accumulated more carotenoids and antioxidants. Wastewater significantly enhanced plant growth when applied once weekly, while becoming toxic when applied twice, reducing biomass and coverage. After scalping, turfgrass recovered well across all treatments, and in some cases biomass improved. Overall, recycled CB byproducts, particularly wastewater used at optimal concentrations, can be a sustainable resource for promoting turfgrass growth. Full article

The NAC gene family plays a crucial role in plant growth, development, and responses to biotic and abiotic stresses. Paspalum Vaginatum, a warm-season turfgrass with exceptional salt tolerance, can be irrigated with seawater. However, the NAC gene family in seashore paspalum remains poorly understood. In this study, genome-wide screening and identification were conducted based on the NAC (NAM) domain hidden Markov model in seashore paspalum, resulting in the identification of 168 PvNAC genes. A phylogenetic tree was constructed, and the genes were classified into 18 groups according to their topological structure. The physicochemical properties of the PvNAC gene family proteins, their conserved motifs and structural domains, cis-acting elements, intraspecific collinearity analysis, GO annotation analysis, and protein–protein interaction networks were analyzed. The results indicated that the majority of PvNAC proteins are hydrophilic and predominantly localized in the nucleus. The promoter regions of PvNACs are primarily enriched with light-responsive elements, ABRE motifs, MYB motifs, and others. Intraspecific collinearity analysis suggests that PvNACs may have experienced a large-scale gene duplication event. GO annotation indicated that PvNAC genes were essential for transcriptional regulation, organ development, and responses to environmental stimuli. Furthermore, the protein interaction network predicted that PvNAC73 interacts with proteins such as BZIP8 and DREB2A to form a major regulatory hub. The transcriptomic analysis investigates the expression patterns of NAC genes in both leaves and roots under varying durations of salt stress. The expression levels of 8 PvNACs in roots and leaves under salt stress were examined and increased to varying degrees under salt stress. The qRT-PCR results demonstrated that the expression levels of the selected genes were consistent with the FPKM value trends observed in the RNA-seq data. This study established a theoretical basis for understanding the molecular functions and regulatory mechanisms of the NAC gene family in seashore paspalum under salt stress. Full article

Cadmium (Cd) is considered to be one of the most toxic metals, causing serious harm to plants’ growth and humans’ health. Therefore, it is necessary to study simple, practical, and environmentally friendly methods to reduce its toxicity. Until now, people have applied zinc sulfate to improve the Cd tolerance of plants. However, related studies have mainly focused on physiological and biochemical aspects, with a lack of in-depth molecular mechanism research. In this study, we sprayed high (40 mM) and low (2.5 mM) concentrations of zinc sulfate on seashore paspalum (Paspalum vaginatum Swartz) plants under 0.5 mM Cd stress. Transcriptome sequencing and physiological indicators were used to reveal the mechanism of Cd tolerance. Compared with the control treatment, we found that zinc sulfate decreased the content of Cd²⁺ by 57.03–73.39%, and that the transfer coefficient of Cd decreased by 58.91–75.25% in different parts of plants. In addition, our results indicate that the antioxidant capacity of plants was improved, with marked increases in the glutathione content and the activity levels of glutathione reductase (GR), glutathione S-transferase (GST), and other enzymes. Transcriptome sequencing showed that the differentially expressed genes in both the 0.5 Zn and 40 Zn treatments were mainly genes encoding GST. This study suggests that genes encoding GST in the glutathione pathway may play an important role in regulating the Cd tolerance of seashore paspalum. Furthermore, the present study provides a theoretical reference for the regulation mechanism caused by zinc sulfate spraying to improve plants’ Cd tolerance. Full article

Turfgrasses are considered an important part of the landscape and ecological system of golf courses, sports fields, parks, and home lawns. Turfgrass species are affected by many abiotic stresses (e.g., drought, salinity, cold, heat, waterlogging, and heavy metals) and biotic stresses (mainly diseases and pests). In the current study, seashore paspalum (Paspalum vaginatum Sw.) and Tifway bermudagrass (Cynodon transvaalensis Burtt Davy × C. Dactylon) were selected because they are popular turfgrasses frequently used for outdoor lawns and sport fields. The effect of the combined stress from both soil salinity and cold on these warm season grasses was investigated. Some selected organic and inorganic amendments (i.e., humic acid, ferrous sulphate, and silicon) were applied as foliar sprays five times during the winter season from late October to March. This was repeated over two years in field trials involving salt-affected soils. The physiological and chemical parameters of the plants, including plant height; fresh and dry weight per plot; total chlorophyll content; and nitrogen, phosphorus, iron, and potassium content, were measured. The results showed that all the studied amendments improved the growth of seashore paspalum and Tifway bermudagrass during this period compared to the control, with a greater improvement observed when using ferrous sulphate and humic acid compared to silicon. For seashore paspalum, the highest chlorophyll content in April was recorded after the application of ferrous sulphate at a level of 1000 ppm. The current research indicates that when grown on salt-affected soils, these amendments can be used in warm-season grasses to maintain turf quality during cold periods of the year. Further research is needed to examine any negative long-term effects of these amendments and to explain their mechanisms. Full article

Seashore paspalum (Paspalum vaginatum Swartz) is a perennial warm-season turfgrass which is known for its superb salinity tolerance. Compared to bermudagrass, seashore paspalum exhibited the adverse character of faster vertical growth, wider leaf, weak cold-, drought- and disease-resistance. In this study, we aimed to improve these unfavorable traits of seashore paspalum through the strategy of callus irradiation. The results showed that 2108 regenerated plants were obtained following the method of the seashore paspalum calluses irradiated by ⁶⁰Co-γ rays (dose: 60 Gy, dose rate: 1 Gy/min). Morphological traits were measured combining with cluster analysis on the regenerated plants to select mutant lines with short leaves (A24 and A82) and thin leaves (A24, A83, and A120) as well as dwarfism (B73, B28, B3, A29, and B74). In addition, we found various mutant characters such as greenish leaf sheath (A69 and A71), soft leaf (B77, B17, and B110), and strong erectness (B5 and B9) under continuous observation. Through the comprehensive tolerance analysis following the index of survive rate, relative water content, leaf electrolyte leakage, MDA content; photochemical efficiency and leaf wilting coefficient, three drought-tolerant lines (A55, B72, and B44) and one cold-tolerant line (B59) were screened. This research proved that callus irradiation is an effective way to create new seashore paspalum germplasm, which provides valuable materials for accelerating the breeding process of seashore paspalum and further excavating the molecular regulatory mechanisms of these traits in turfgrass. Full article

The use of slow-growing Seashore paspalum dwarf varieties is an effective way to reduce mowing frequency. Here, the differences in metabolism and hormone levels between Seashore paspalum dwarf mutant T51 and WT were investigated. Finally, the genes associated with the dwarf phenotype were screened in combination with our previous studies. At the metabolic level, 236 differential metabolites were identified. Further screening of hormone-related differential metabolites found that ABA and SA of T51 were increased significantly, while IAA and its intermediate metabolite indolepyruvate of T51 were decreased significantly. Endogenous hormone content assay showed that there was no difference in GA and BR content between T51 and WT; However, the IAA content of T51 was significantly reduced compared with WT. The results of exogenous hormone treatment showed that the sensitivity of T51 to exogenous hormones was IAA > GA > BR. TAA1, YUCCA, and NIT were down-regulated at both the transcriptional and protein levels; CYP79B2 and CYP79B3 were down-regulated at the protein level but had no difference at the transcriptional level. In conclusion, we propose that the down-regulated expression of TAA1, YUCCA, NIT, CYP79B2, and CYP79B3 leads to the decrease of IAA content, which is one of the important reasons for the dwarf phenotype of T51; TAA1, YUCCA, and NIT are important candidate genes related to T51 dwarf. Full article

We sampled 127 turfgrass soil samples from 33 golf courses in NC, EC, and SC for plant-parasitic nematodes (PPNs). PPNs were extracted from soil samples using the shallow dish method and were identified at the genus or species levels with a combination of morphological and molecular methods. The results revealed 41 species of nematode belonging to 20 genera and 10 families. Nine genera are new records of PPNs associated with turfgrass in China. The PPNs show strong geographical distributions. Of the 20 genera, Helicotylenchus, Paratrichodorus, Hoplolaimus, Meloidogyne, Hemicriconemoides, and Mesocriconema showed higher infestation and frequency, and most of these genera had numbers in soil samples above established damage thresholds. Four golf courses had soil samples with PPNs > 30%, indicating the potential for nematode damage. The biodiversity indices H’, SR, J’, λ, and H₂ showed significant differences among different regions and turfgrass species; H’, SR, J’, and H₂ were significantly higher in EC than in NC and SC, while λ was lowest in EC. Creeping bentgrass had the highest H’, SR, J’, and H₂ and the lowest λ in comparison with seashore paspalum and hybrid bermudagrass. These findings provide baseline information on the occurrence of turfgrass-associated PPNs in China, and have important implications for the effective management of PPNs causing damage on turfgrass. Full article

A plastic pot open-air trial was conducted with the Paspalum vaginatum (seashore paspalum) using different rates of biochar or compost addition to sandy loam soil and two water treatments (60% and 20% of the water-holding capacity of the control) during three seasons (winter, spring, and summer). Paspalum growth, physiological characteristics, and physicochemical properties of soil were investigated. The effect of biochar on soil properties was assessed using factor analysis of mixed data (FAMD). Additionally, multiple factorial designs (MFA) were used to examine the impact of three biochars on physiological functions. Peanut hull biochar application increased soil fertility and chlorophyll concentration of paspalum leaves significantly compared to the other biochars. Physiological characteristics were significantly improved with peanut hull biochar under summer compared to winter and spring due to the accumulation of nutrients in the soil by the decomposition of biochar. The application rate of the three biochars reduced the water requirements of paspalum. The best result was obtained by incorporating 6% peanut hull biochar into the soil, which resulted in better soil quality and healthy grass in dryland conditions while using 47.5% less water. These findings can be suitable for golf managers and can serve as a solution for dry zones. Full article

The effects of pyrolyzed agricultural waste generated from banana leaves on the development and physiological responses of Paspalum vaginatum in different water conditions were investigated. X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) computations were utilized to describe the banana-waste biochar and determine the crystalline structure and functional groups. A plastic pot was used in two trials to examine the effectiveness of the studied biochar under two situations (well-watered Ww and limited-watered Lw). Seashore paspalum was cultivated in loam soil that had been modified with biochar as a single addition and a biochar compost mix. Six water scarcity scenarios were chosen (100, 80, 60, 25, 20, and 15% of water holding capacity (WHC) of the control soil). To analyze the varied responses of P. vaginatum in well-watered and limited-water environments, principal component analysis (PCA) was used. Under Ww, photosynthesis, biomass, fluorescence, and chlorophyll content increased, whereas, under Lw and control, they declined. Biochar and compost combinations enhanced the relative water content (RWC) more than biochar alone or in combination. Conversely, stomatal density in drought-stricken plants showed the reverse trend. Full article

Seashore paspalum is a major warm-season turfgrass requiring frequent mowing. The use of dwarf cultivars with slow growth is a promising method to decrease mowing frequency. The present study was conducted to provide an in-depth understanding of the molecular mechanism of T51 dwarfing in the phenylpropane pathway and to screen the key genes related to dwarfing. For this purpose, we obtained transcriptomic information based on RNA-Seq and proteomic information based on iTRAQ for the dwarf mutant T51 of seashore paspalum. The combined results of transcriptomic and proteomic analysis were used to identify the differential expression pattern of genes at the translational and transcriptional levels. A total of 8311 DEGs were detected at the transcription level, of which 2540 were upregulated and 5771 were downregulated. Based on the transcripts, 2910 proteins were identified using iTRAQ, of which 392 (155 upregulated and 237 downregulated) were DEPs. The phenylpropane pathway was found to be significantly enriched at both the transcriptional and translational levels. Combined with the decrease in lignin content and the increase in flavonoid content in T51, we found that the dwarf phenotype of T51 is closely related to the abnormal synthesis of lignin and flavonoids in the phenylpropane pathway. CCR and HCT may be the key genes for T51 dwarf. This study provides the basis for further study on the dwarfing mechanism of seashore paspalum. The screening of key genes lays a foundation for further studies on the molecular mechanism of seashore paspalum dwarfing. Full article

The continuing decline in global drinking water reserves necessitates finding alternative water sources for turfgrass irrigation, especially in southern semi-arid Mediterranean countries. The aim of the present study was to evaluate the potential of using seawater for irrigating two varieties of seashore paspalum (Paspalum vaginatum Sw.), “Marina” and “Platinum ΤΕ”, growing in shallow green roof substrates, and to determine their recuperative capacity after the termination of the salt stress period. The greenhouse study comprised of 48 lysimeters equipped with extensive green roof layering. Treatments included: (i) two substrate depths (7.5 cm or 15 cm) and (ii) three seawater irrigation regimes (7 mm, 15 mm, or 45 mm every two days). Measurements included the determination of green turf cover (GTC) as well as the leaching fraction (LF) and leachate electrical conductivity (EC_L) draining from the lysimeters. It was found that during the 46-d salt stress period, none of the seawater irrigation regimes managed to maintain acceptable GTC levels for both seashore paspalum varieties. Increasing the green roof substrate depth from 7.5 cm to 15 cm resulted in GTC improvement. During the recovery period, the use of potable water as irrigation source improved GTC levels. After 40 d the recovery was complete since GTC exceeded 90% in all treatments for both varieties. Regression curves correlating GTC response to EC_L can be used to estimate the leaching requirements of turfgrasses grown in shallow green roof systems when irrigated with saline water. Full article

Soil nitrification (microbial oxidation of ammonium to nitrate) can lead to nitrogen leaching and environmental pollution. A number of plant species are able to suppress soil nitrifiers by exuding inhibitors from roots, a process called biological nitrification inhibition (BNI). However, the BNI activity of perennial grasses in the nutrient-poor soils of Australia and the effects of BNI activity on nitrifying microbes in the rhizosphere microbiome have not been well studied. Here we evaluated the BNI capacity of bermudagrass (Cynodon dactylon L.), St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze), saltwater couch (Sporobolus virginicus), seashore paspalum (Paspalum vaginatum Swartz.), and kikuyu grass (Pennisetum clandestinum) compared with the known positive control, koronivia grass (Brachiaria humidicola). The microbial communities were analysed by sequencing 16S rRNA genes. St. Augustinegrass and bermudagrass showed high BNI activity, about 80 to 90% of koronivia grass. All the three grasses with stronger BNI capacities suppressed the populations of Nitrospira in the rhizosphere, a bacteria genus with a nitrite-oxidizing function, but not all of the potential ammonia-oxidizing archaea. The rhizosphere of saltwater couch and seashore paspalum exerted a weak recruitment effect on the soil microbiome. Our results demonstrate that BNI activity of perennial grasses played a vital role in modulating nitrification-associated microbial populations. Full article

Seashore paspalum (Paspalum vaginatum) is among the most salt- and cadmium-tolerant warm-season perennial grass species widely used as turf or forage. The objective of this study was to select stable reference genes for quantitative real-time polymerase chain reaction (qRT-PCR) analysis of seashore paspalum in response to four abiotic stresses. The stability of 12 potential reference genes was evaluated by four programs (geNorm, NormFinder, BestKeeper, and RefFinder). U2AF combined with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) showed stable expression in Cd-treated leaves and cold-treated roots. U2AF and FBOX were the most stable reference genes in Cd-treated roots and cold-treated leaves. In Polyethylene Glycol (PEG)- or salt-treated roots, the reference gene U2AF paired with either ACT or CYP were stable. SAND and CACS exhibited the most stability in salt-treated leaves, and combining UPL, PP2A, and EF1a was most suitable for PEG-treated leaves. The stability of U2AF and instability of UPL and TUB was validated by analyzing the expression levels of four target genes (MT2a, VP1, PIP1, and Cor413), and were shown to be capable of detecting subtle changes in expression levels of the target genes in seashore paspalum. This study demonstrated that FBOX, U2AF, and PP2A could be used in future molecular studies that aim to understand the mechanisms of abiotic stress tolerance in seashore paspalum. Full article