Whole-genome sequencing of allotetraploid bermudagrass reveals the origin of Cynodon and candidate genes for salt tolerance

Bermudagrass (Cynodon dactylon) is a globally distributed, extensively used warm-season turf and forage grass with high tolerance to salinity and drought stress in alkaline environments. However, the origin of the species and genetic mechanisms for salinity tolerance in the species are basically unknown. Accordingly, we set out to study evolution divergence events in the Cynodon genome and to identify genes for salinity tolerance. We developed a 604.0 Mb chromosome-level polyploid genome sequence for bermudagrass 'A12359' (n = 18). The C. dactylon genome comprises 2 complete sets of homoeologous chromosomes, each with approximately 30 000 genes, and most genes are conserved as syntenic pairs. Phylogenetic study showed that the initial Cynodon species diverged from Oropetium thomaeum approximately 19.7-25.4 million years ago (Mya), the A and B subgenomes of C. dactylon diverged approximately 6.3-9.1 Mya, and the bermudagrass polyploidization event occurred 1.5 Mya on the African continent. Moreover, we identified 82 candidate genes associated with seven agronomic traits using a genome-wide association study, and three single-nucleotide polymorphisms were strongly associated with three salt resistance genes: RAP2-2, CNG channels, and F14D7.1. These genes may be associated with enhanced bermudagrass salt tolerance. These bermudagrass genomic resources, when integrated, may provide fundamental insights into evolution of diploid and tetraploid genomes and enhance the efficacy of comparative genomics in studying salt tolerance in Cynodon.

Dairy Effluent-Saturated Biochar's Short-Term Effects on Vigna unguiculata and Cynodon dactylon Performance and Soil Properties

We compared the effects of wood-, manure-, and blend-derived biochar (BC) saturated/unsaturated with dairy effluents on Vigna unguiculata and Cynodon dactylon performance and soil characteristics in a greenhouse pot study. Plant samples were assayed for herbage and root dry weight and N and C percentages. Soil samples were assayed for nutrients, pH, and conductivity. Variance analysis, Tukey's tests, Pearson's correlations, and multiple regression analysis were performed. The performance of C. dactylon was not affected. V. unguiculata's herbage and root production responded negatively to manure BC and 2% of any BC, respectively, which is mainly explained by the conductivity and soil P increase, respectively. When V. unguiculata was grown, BC inclusion decreased NO3-N and increased the soil P content. When C. dactylon was grown, only P was altered (increased) when manure or the blend BC were applied. The soil total C increased as the BC loading rate increased. The application of high BC rates was detrimental for V. unguiculata, but showed a neutral effect for C. dactylon. To improve dairy waste recycling, saturated 1% blend BC and saturated 2% blend or manure BC could be applied to V. unguiculata and C. dactylon, respectively, with no short-term negative impacts. Only wood BC avoided soil P build-up. BC application increased the soil total C, showing potential for C sequestration.

Biochar and Dairy Manure Amendment Effects on Cynodon dactylon Performance and Soil Properties

Studies have determined the separate effects of biochar (BC) and manure application on forage species and soil, but few examined the effects of BCs made from different feedstock applied along with dairy manure. We compared the effect of wood- and manure-derived feedstock BC as well as dairy manure amendment application on Cynodon dactylon performance and soil properties in sandy loam and clay loam soils in a greenhouse pot study. Plant samples were assayed for herbage and root dry weight as well as herbage and root N and C percent and yield. Soil samples were assayed for macronutrients, micronutrients, metals, pH and conductivity. Data analyses involved variance analysis and Tukey's tests using R in RStudio (the IDE). In general, C. dactylon yields or mineral content were not affected by either manure or BC. However, an increase in the total herbage dry weight (30%) and in herbage N% (55%) was observed for clay loam and sandy loam soil, respectively, due to manure amendment application. There were no alterations in clay loam NO3-N and P due to any treatment; however, in sandy loam, these nutrients were not altered only when wood BC was applied. In sandy loam soil, NO3-N and P increased when manure BC along with dairy manure and when manure BC alone were applied, respectively. Thus, wood BC application should be considered to avoid these nutrient buildups when dairy manure is used as a soil amendment. This research shows a neutral (BC) or positive (dairy manure amendment) impact on C. dactylon performance. BC incorporation increases soil total C, showing potential for C sequestration. Long-term field trials could corroborate plant performance and soil parameters.

Evaluation of antimicrobial, anti-inflammatory and cytotoxic effects of silver nanoparticles synthesised from Cynodon dactylon

Plant mediated synthesis of metal nanoparticles (MNPs) has been considered as a reliable green technique for mitigating the involvement of toxic chemicals and which is widely used for desired applications. In the present study, a simple and environment friendly approach for the synthesis of silver nanoparticles (AgNPs) using the aqueous extract of Cynodon dactylon was proposed. The phytochemicals present in C. dactylon acted as the reducing as well as the capping agents during the nanoparticle synthesis. The aqueous extract of C. dactylon added to AgNO3 solution showed a colour change from brown to black at room temperature which confirmed the formation of AgNPs. UV-Vis spectral analysis revealed the surface plasmon resonance band of synthesised AgNPs at around 380 nm, while FT-IR spectroscopy confirmed the role of biomolecules present in the plant extract in the reduction and efficient stabilisation of AgNPs. The X-ray diffraction (XRD) patterns confirmed distinctive peaks corresponding to the crystalline planes of cubic silver. Shape and surface morphology of green AgNPs were examined by SEM. Biosynthesized AgNPs were predominantly cubical and spherical with an average particle size of 30.5 nm approximately as observed through SEM and DLS analysis respectively. The EDS analysis displayed intense signals of silver element. The stability of AgNPs was confirmed by zeta potential analysis. A negative zeta potential value of -17.1 mV indicated the stability and good dispersion of AgNPs. Antimicrobial and anti-inflammatory potentials of green synthesised AgNPs were analysed through in vitro techniques. The cytotoxic effect of green AgNPs on normal fibroblast cells (L929) was studied to analyse its effect on normal cells.

Growth characteristics of Cynodon dactylon and mechanical properties of slope with different sludge contents

The utilization of dredged sludge can reduce environmental pollution and save land resources. To explore using sludge resources in ecological slope-protection projects, dredged sludge was incorporated into ecological slope-protection soil. Cynodon dactylon was planted to analyze the effect of sludge content on its growth. Direct-shear tests on the slope-protection soil with and without Cynodon dactylon were conducted to elaborate on the effect of sludge content, water content, and roots on the mechanical properties of the sludge-clay mixture. When the sludge content was <50%, Cynodon dactylon's growth improved with the sludge content increase, but at >50%, the sludge content's effect was meagre. As the sludge content increased, the cohesion and internal friction angle of the sludge-clay mixture without roots decreased, lowering the shear strength. The soil's cohesive force and internal friction angle follows the sequence: natural state with roots > natural state without roots > saturated state with roots > saturated state without roots. The cohesion and shear strength of the sludge-clay mixture with roots increased at first before decreasing with an increase in sludge content, optimized at 50% sludge content. Here, the ecological slope stability was the best, meaning that the optimum sludge proportion was 50%.

Application of Three Compounds Extracted from Cynodon dactylon against Streptococcus mutans Biofilm Formation to Prevent Oral Diseases

Streptococcus mutans bacteria form a biofilm called plaque that causes oral diseases, including tooth decay. Therefore, inhibition of biofilm formation is essential to maintaining good oral health. The health and nutritional benefits of Cynodon dactylon are well documented, but very little is known about its use to treat against oral diseases. The aim of this study was to detect the adhesion strength of the S. mutans bacterial biofilm in 100 cases in the Rajshahi region and evaluate the inhibitory activity of different compound extracts of C. dactylon on the S. mutans bacterial biofilm by determining the composition of isolated compounds using phytochemical analysis. Nuclear magnetic resonance (NMR) spectroscopy confirmed that three specific compounds from C. dactylon were discovered in this study: 3,7,11,15 tetramethyl hexadec-2-4dien 1-o1, compound 3,7,11,15 tetramethylhexadec-2-en-1-o1 from phytol derivatives, and stigmasterol. Results indicated that the compound of 3,7,11,15-tetramethyl-hexadec-2-en-1-ol exhibited higher antibiofilm activities on S. mutans than those of the other compound extracts. A lower level of minimum inhibitory concentration was exposed by 3, 7, 11,15 tetramethyl hexadeca-2-en-1-o1 (T2) on S. mutans at 12.5 mL. In this case, the compound of 3,7,11,15 tetramethyl hexadec 2en-1-o1 was used, and patients showed a mean value and standard error reduced from 3.42 ± 0.21 to 0.33 ± 0.06 nm. The maximum inhibition was (80.10%) in the case of patient no. 17, with a value of p < 0.05 found for S. mutans to which 12.5 μL/mL ethyl acetate extract was applied. From these findings, it may be concluded that C. dactylon extracts can be incorporated into various oral preparations to prevent tooth decay.

Primary plant nutrients modulate the reactive oxygen species metabolism and mitigate the impact of cold stress in overseeded perennial ryegrass

Overseeded perennial ryegrass (Lolium perenne L.) turf on dormant bermudagrass (Cynodon dactylon Pers. L) in transitional climatic zones (TCZ) experience a severe reduction in its growth due to cold stress. Primary plant nutrients play an important role in the cold stress tolerance of plants. To better understand the cold stress tolerance of overseeded perennial ryegrass under TCZ, a three-factor and five-level central composite rotatable design (CCRD) with a regression model was used to study the interactive effects of nitrogen (N), phosphorus (P), and potassium (K) fertilization on lipid peroxidation, electrolyte leakage, reactive oxygen species (ROS) production, and their detoxification by the photosynthetic pigments, enzymatic and non-enzymatic antioxidants. The study demonstrated substantial effects of N, P, and K fertilization on ROS production and their detoxification through enzymatic and non-enzymatic pathways in overseeded perennial ryegrass under cold stress. Our results demonstrated that the cold stress significantly enhanced malondialdehyde, electrolyte leakage, and hydrogen peroxide contents, while simultaneously decreasing ROS-scavenging enzymes, antioxidants, and photosynthetic pigments in overseeded perennial ryegrass. However, N, P, and K application mitigated cold stress-provoked adversities by enhancing soluble protein, superoxide dismutase, peroxide dismutase, catalase, and proline contents as compared to the control conditions. Moreover, N, P, and, K application enhanced chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in overseeded perennial ryegrass under cold stress as compared to the control treatments. Collectively, this 2-years study indicated that N, P, and K fertilization mitigated cold stress by activating enzymatic and non-enzymatic antioxidants defense systems, thereby concluding that efficient nutrient management is the key to enhanced cold stress tolerance of overseeded perennial ryegrass in a transitional climate. These findings revealed that turfgrass management will not only rely on breeding new varieties but also on the development of nutrient management strategies for coping cold stress.

Nitrogen fixation of Cyndon dactylon: A possible strategy coping with long-term flooding in the Three Gorges Reservoir

The Three Gorges Reservoir (TGR) is one of the largest hydropower projects around the world which greatly alters the ecological function of the original ecosystem. The riparian zone of TGR is subject to a frequent fluctuation of water level, leading to severe nitrogen loss by leaching. Cyndon dactylon, a perennial stress tolerant plant, is one of the dominant plant species in the riparian zone of TGR. The underlying mechanism that C. dactylon can survive the nitrogen limitation has been under debate. In this study, we sampled the plant tissues of C. dactylon and the surrounding soils across different water levels and seasons in the riparian zone of TGR to explore the possible strategy for them to mining nitrogen. Our study found that the C. dactylon in the TGR riparian zone had endophytic nitrogen-fixing bacteria, particularly enriched in the plant foliage. The abundance of endophytic nitrogen-fixing bacteria was significantly negatively correlated with soil ammonia, nitrate, and organic matter, and significantly positively correlated with total phosphorous and moisture content. The endophytic nitrogen-fixing bacteria in C. dactylon were highly diverse, with Proteobacteria as the main dominant genera. The mutual cooperation mode among bacterial species made the endophytic nitrogen-fixing bacteria community of C. dactylon more resilient to environmental pressure, thus more readily adapting to conditions of repeated long-term flooding in the riparian zone of the TGR.

Interspecific Drought Cuing in Plants

Plants readily communicate with their pollinators, herbivores, symbionts, and the predators and pathogens of their herbivores. We previously demonstrated that plants could exchange, relay, and adaptively utilize drought cues from their conspecific neighbors. Here, we studied the hypothesis that plants can exchange drought cues with their interspecific neighbors. Triplets of various combinations of split-root Stenotaphrum secundatum and Cynodon dactylon plants were planted in rows of four pots. One root of the first plant was subjected to drought while its other root shared its pot with one of the roots of an unstressed target neighbor, which, in turn, shared its other pot with an additional unstressed target neighbor. Drought cuing and relayed cuing were observed in all intra- and interspecific neighbor combinations, but its strength depended on plant identity and position. Although both species initiated similar stomatal closure in both immediate and relayed intraspecific neighbors, interspecific cuing between stressed plants and their immediate unstressed neighbors depended on neighbor identity. Combined with previous findings, the results suggest that stress cuing and relay cuing could affect the magnitude and fate of interspecific interactions, and the ability of whole communities to endure abiotic stresses. The findings call for further investigation into the mechanisms and ecological implications of interplant stress cuing at the population and community levels.

Cytotoxic Potential of Bioactive Compounds from Aspergillus flavus, an Endophytic Fungus Isolated from Cynodon dactylon, against Breast Cancer: Experimental and Computational Approach

Endophytic fungi are a diverse group of microorganisms that colonize the inter- or intracellular spaces of plants and exhibit mutual benefits. Their interactions with the host plant and other microbiomes are multidimensional and play a crucial role in the production of secondary metabolites. We screened bioactive compounds present in the extracts of Aspergillus flavus, an endophytic fungus isolated from the roots of the medicinal grass Cynodon dactylon, for its anticancer potential. An in vitro analysis of the Ethyl acetate extract from A. flavus showed significant cytostatic effects (IC₅₀: 16.25 μg/mL) against breast cancer cells (MCF-7). A morphological analysis of the cells and a flow cytometry of the cells with annexin V/Propidium Iodide suggested that the extract induced apoptosis in the MCF-7 cells. The extract of A. flavus increased reactive oxygen species (ROS) generation and caused a loss of mitochondrial membrane potential in MCF-7 cells. To identify the metabolites that might be responsible for the anticancer effect, the extract was subjected to a gas chromatography-mass spectrometry (GC-MS) analysis. Interestingly, nine phytochemicals that induced cytotoxicity in the breast cancer cell line were found in the extract. The in silico molecular docking and molecular dynamics simulation studies revealed that two compounds, 2,4,7-trinitrofluorenone and 3α, 5 α-cyclo-ergosta-7,9(11), 22t-triene-6beta-ol exhibited significant binding affinities (-9.20, and -9.50 Kcal/mol, respectively) against Bcl-2, along with binding stability and intermolecular interactions of its ligand-Bcl-2 complexes. Overall, the study found that the endophytic A. flavus from C. dactylon contains plant-like bioactive compounds that have a promising effect in breast cancer.

Proteome-wide analyses reveal diverse functions of protein acetylation and succinylation modifications in fast growing stolons of bermudagrass (Cynodon dactylon L.)

BACKGROUND

Bermudagrass (Cynodon dactylon L.) is an important warm-season turfgrass species with well-developed stolons, which lay the foundation for the fast propagation of bermudagrass plants through asexual clonal growth. However, the growth and development of bermudagrass stolons are still poorly understood at the molecular level.

RESULTS

In this study, we comprehensively analyzed the acetylation and succinylation modifications of proteins in fast-growing stolons of the bermudagrass cultivar Yangjiang. A total of 4657 lysine acetylation sites on 1914 proteins and 226 lysine succinylation sites on 128 proteins were successfully identified using liquid chromatography coupled to tandem mass spectrometry, respectively. Furthermore, 78 proteins and 81 lysine sites were found to be both acetylated and succinylated. Functional enrichment analysis revealed that acetylated proteins regulate diverse reactions of carbohydrate metabolism and protein turnover, whereas succinylated proteins mainly regulate the citrate cycle. These results partly explained the different growth disturbances of bermudagrass stolons under treatment with sodium butyrate and sodium malonate, which interfere with protein acetylation and succinylation, respectively. Moreover, 140 acetylated proteins and 42 succinylated proteins were further characterized having similarly modified orthologs in other grass species. Site-specific mutations combined with enzymatic activity assays indicated that the conserved acetylation of catalase and succinylation of malate dehydrogenase both inhibited their activities, further implying important regulatory roles of the two modifications.

CONCLUSION

In summary, our study implied that lysine acetylation and succinylation of proteins possibly play important regulatory roles in the fast growth of bermudagrass stolons. The results not only provide new insights into clonal growth of bermudagrass but also offer a rich resource for functional analyses of protein lysine acetylation and succinylation in plants.

Synthesis of copper nanoparticles from the aqueous extract of Cynodon dactylon and evaluation of its antimicrobial and photocatalytic properties

The copper nanoparticles (CuNPs) synthesizing potential of Cynodon dactylon aqueous leaf extract and their antibacterial as well as dye degradation potentials were investigated. The synthesized CuNPs was initially characterized by gradual colour change from dark brown to blue in colour and then found absorbance peak at 469 nm. Furthermore, the SEM and DLS analyses showed that biosynthesized CuNPs were spherical in shaped and size ranging from 120 to 129 nm. The FTIR spectrum confirmed the presence of flavonoids, alkaloids, terpenoids, and phenols, which involved in the reduction, capping, and stabilization of CuNPs. This green synthesized CuNPs also demonstrated remarkable antibacterial activity against the bacterial pathogens such as Escherichia coli, Bacillus subtilis and Staphylococcus aureus and Klebsiella pneumoniae. This green synthesized CuNPs exhibited considerable dye degrading potential in the following order as methyl organge > methyl red > Erichrome black T dyes in the presence of sunlight through photocatalytic degradation process. These results conclude that C. dactylon aqueous leaf extract mediated nanoparticles possess remarkable antibacterial and dye degrading potential.

Expression of a Cytochrome P450 Gene from Bermuda Grass Cynodon dactylon in Soybean Confers Tolerance to Multiple Herbicides

Bermuda grass (Cynodon dactylon) is notoriously difficult to control with some commonly used herbicides. We cloned a cytochrome P450 gene from Bermuda grass, named P450-N-Z1, which was found to confer tolerance to multiple herbicides in transgenic Arabidopsis. These herbicides include: (1) acetolactate synthase (ALS) inhibitor herbicides nicosulfuron and penoxsulam; (2) p-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide mesotrione; (3) synthetic auxin herbicide dicamba; (4) photosynthesis inhibitor bentazon. We further generated transgenic soybean plants expressing P450-N-Z1, and found that these transgenic soybean plants gained robust tolerance to nicosulfuron, flazasulfuron, and 2,4-dichlorophenoxyacetic acid (2,4-D) in greenhouse assays. A field trial demonstrated that transgenic soybean is tolerant to flazasulfuron and 2,4-D at 4-fold and 2-fold the recommended rates, respectively. Furthermore, we also demonstrated that flazasulfuron and dicamba are much more rapidly degraded in vivo in the transgenic soybean than in non-transgenic soybean. Therefore, P450-N-Z1 may be utilized for engineering transgenic crops for herbicide tolerance.

A High-Quality Haplotype-Resolved Genome of Common Bermudagrass (Cynodon dactylon L.) Provides Insights Into Polyploid Genome Stability and Prostrate Growth

Common bermudagrass (Cynodon dactylon L.) is an important perennial warm-season turfgrass species with great economic value. However, the reference genome is still deficient in C. dactylon, which severely impedes basic studies and breeding studies. In this study, a high-quality haplotype-resolved genome of C. dactylon cultivar Yangjiang was successfully assembled using a combination of multiple sequencing strategies. The assembled genome is approximately 1.01 Gb in size and is comprised of 36 pseudo chromosomes belonging to four haplotypes. In total, 76,879 protein-coding genes and 529,092 repeat sequences were annotated in the assembled genome. Evolution analysis indicated that C. dactylon underwent two rounds of whole-genome duplication events, whereas syntenic and transcriptome analysis revealed that global subgenome dominance was absent among the four haplotypes. Genome-wide gene family analyses further indicated that homologous recombination-regulating genes and tiller-angle-regulating genes all showed an adaptive evolution in C. dactylon, providing insights into genome-scale regulation of polyploid genome stability and prostrate growth. These results not only facilitate a better understanding of the complex genome composition and unique plant architectural characteristics of common bermudagrass, but also offer a valuable resource for comparative genome analyses of turfgrasses and other plant species.

Integrated physiological and transcriptomic analyses of two warm- and cool-season turfgrass species in response to heat stress

Warm- and cool-season turfgrasses were originated from different locations with contrasting heat tolerance. The molecular mechanisms of heat tolerance have not been extensively studied in turfgrass species. In this study, transcriptomic analysis showed that bermudagrass was more tolerant to heat stress as evidenced by lower contents of H₂O₂, proline and glutathione than those in tall fescue after heat treatment. RNA sequencing analysis revealed that 32.7% and 17.7% more genes were changed in tall fescue than in bermudagrass after 2 and 12h heat treatment, respectively. GO terms of redox were enriched in bermudagrass whereas metabolite transportation ones were over-represented in tall fescue after 2h treatment. Ubiquitin dependent degradation pathways were commonly regulated in both grass species. CdF-box and FaF-box transgenic Arabidopsis exhibited improved tolerance to heat stress. Regulatory elements analysis revealed that four ABA-responsive elements present in CdF-box promoter, indicating CdF-box could be potentially regulated by ABRE binding factors (ABFs). All these findings provide evidences for understanding heat stress response in warm- and cool-season grass species.

Graph theoretical network analysis, in silico exploration, and validation of bioactive compounds from Cynodon dactylon as potential neuroprotective agents against α-synuclein

Introduction: Parkinson's disease (PD) is a chronic, devastating neurodegenerative disorder marked by the death of dopaminergic neurons in the midbrain's substantia nigra pars compacta (Snpc). In alpha-synuclein (α-Syn) self-aggregation, the existence of intracytoplasmic inclusion bodies called Lewy bodies (LBs) and Lewy neurites (LNs) causes PD, which is a cause of neuronal death. Methods: The present study is aimed at finding potential bioactive compounds from Cynodon dectylon that can degrade α-Syn aggregation in the brain, through in silico molecular docking investigations. Graph theoretical network analysis was used to identify the bioactive compounds that target α-Syn and decipher their network as a graph. From the data repository, twenty-nine bioactive chemicals from C. dactylon were chosen and their structures were retrieved from Pubchem. On the basis of their docking scores and binding energies, significant compounds were chosen for future investigation. The in silico prediction of chosen compounds, and their pharmacokinetic and physicochemical parameters were utilized to confirm their drug-likeness profile. Results: During molecular docking investigation the bioactive compounds vitexin (-7.3 kcal.mol^-1) and homoorientin (-7.1 kcal.mol^-1) showed significant binding energy against the α-Syn target protein. A computer investigation of molecular dynamics simulation study verifies the stability of the α-Syn-ligand complex. The intermolecular interactions assessed by the dynamic conditions indicate that the bioactive compound vitexin has the potency to prevent α-Syn aggregation. Conclusion: Interestingly, the observed results indicate that vitexin is a potential lead compound against α-Syn aggregation, and in vitro and in vivo studies are warranted to confirm the promising therapeutic capability.

Synthesis of novel adsorbent by incorporation of plant extracts in amino-functionalized silica-coated magnetic nanomaterial for the removal of Zn2+and Cu2+from aqueous solution

Magnetic nanoparticles owing to their superparamagnetic behaviour and specific reactive sites are facilitated to regenerate and reuse. Our present study determines the cointegration of the plant extracts of Cynodon dactylon and Muraya koenigii with the magnetic nanoparticle coated with silica layer and surface engineered with a specific amine group. The cointegrated magnetic nano adsorbent is characterized for its analytical feature and batch studies are performed to remove zinc (Zn²⁺) copper (Cu²⁺) metal ions. Fourier transform infrared spectroscopy reveals the presence of functional entities such as NH₂, Si-O-Si, C=C. The size of the cointegrated nano adsorbent (12-30 nm) was confirmed by field emission scanning electron microscopy whereas, a high-resolution transmission electron microscope affirms the nanosize of the particle constituted around 20 nm. Energy dispersive x-ray analysis confirms the presence of elements like Fe, N, Si and was confirmed by X-ray diffraction analysis and vibrating sample magnetometer affirms the superparamagnetic nature with the high magnetic saturation value (M_s - 30 emug^-1). The cointegrated nano adsorbent reveals the maximum adsorption capacity of Zn²⁺ as 78.24 mg.g^-1 and Cu²⁺ as 81.76 mg.g^-1 of the adsorbent under the optimized conditions of contact time 45 min, pH 6.0 and temperature 35 °C. Kinetics such as pseudo-first-order, pseudo-second-order, Elovich, intraparticle diffusion and isotherm studies like Langmuir, Freundlich, Dubinin-Radushkevich and Temkin were performed to understand the mechanism of interaction between the nanoadsorbent and metal ions. The reaction system follows the pseudo-second-order kinetics and Langmuir isotherm model for both the Cu²⁺ and Zn²⁺ metal ions. To determine the reusing capacity of the cointegrated nanoadsorbent, the adsorption efficiency was studied for continuous twelve cycles with 80% recovery after subsequent acid treatment.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40201-021-00696-9.

Electrophysiological responses of Philaenus spumarius and Neophilaenus campestris females to plant volatiles

The spittlebugs Philaenus spumarius and Neophilaenus campestris (Hemiptera: Aphrophoridae) are xylem-feeder insects that have been identified as vectors of Xylella fastidiosa in Europe. In the present study, we aim to identify volatile organic compounds (VOCs) that may act as semiochemicals for these species. Using the dynamic headspace technique, we collected VOCs from Olea europaea L. and Polygala myrtifolia L., highly susceptible plant species to X. fastidiosa, Pinus halepensis Mill., a common plant where N. campestris is found during summer, and from host plant species that are used as cover crops or exist as natural vegetation in olive orchards, such as Cistus creticus L., Medicago sativa L., Cynodon dactylon (L.) Pers., Lolium arundinaceum (Schreb.) Darbysh., Apium graveolens L. and Petroselinum crispum (Mill.) Fuss. We tested the response of female antennae on those blends with Gas Chromatography-Electroantennographic Detection (GC-EAD). The chemical profile of C. creticus and P. halepensis was rich in terpenes, alcohols, aldehydes, and esters. In the O. europaea profile, the main compounds were terpenes. As for P. myrtifolia, the volatile profile consisted mostly of alkanes and their substitutes. In the volatile profile of M. sativa, C. dactylon and L. arundinaceum, common volatile compounds were detected. Petroselinum crispum and Apium graveolens chemical profiles were dominated by terpenes. Several compounds elicited a consistent response to the female antennae of both species. In total, 65 compounds elicited consistent EAD responses for P. spumarius and 16 compounds for N. campestris. α-pinene was found in all tested plants and elicited consistent EAD responses of P. spumarius in five plants. In addition, antennae of P. spumarius females responded to camphor, limonene, 4-methyl octane and sabinene. These compounds were found in the volatile profile of at least 5 out of 8 examined plant species. Behavioral bioassays using Y-tube olfactometry were performed on volatiles that elicited antennal responses during electrophysiological studies. Among the compounds tested in behavioral studies, namely (-)-α-pinene, (+)-α-pinene, sabinene, (-)-S-limonene and (1R)-(+)-camphor, only the last one elicited a significant attraction response by P. spumarius females. The results achieved shed light on the VOCs from selected host plant species of X. fastidiosa that are perceived by two important insect vectors and a non-host plant, P. crispum. The identification of semiochemicals for manipulating spittlebugs' behavior contribute to the development of efficient monitoring tools for X. fastidiosa vectors.

Non-linear genetic diversity and notable population differentiation caused by low gene flow of bermudagrass [Cynodon dactylon (L.) Pers.] along longitude gradients

Background

Environmental variation related to ecological habitat is the main driver of plant adaptive divergence. Longitude plays an important role in the formation of plant population structure, indicating that environmental differentiation can significantly shape population structure.

Methods

Genetic diversity and population genetic structure were estimated using 105 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. A total of 249 C. dactylon (L.) Pers. (common bermudagrass) individuals were sampled from 13 geographic sites along the longitude (105°57′34″–119°27′06″E).

Results

There was no obvious linear trend of intra-population genetic diversity along longitude and the intra-population genetic diversity was not related to climate in this study. Low gene flow (Nm = 0.7701) meant a rich genetic differentiation among populations of C. dactylon along longitude gradients. Significantly positive Mantel correlation (r = 0.438, P = 0.001) was found between genetic distance and geographical interval while no significant partial Mantel correlation after controlling the effect of mean annual precipitation, which indicated geographic distance correlated with mean annual precipitation affect genetic distance. The genetic diversity of C. dactylon with higher ploidy level was higher than that with lower ploidy level and groups of individuals with higher ploidy level were separated further away by genetic distance from the lower ploidy levels. Understanding the different genetic bases of local adaptation comparatively between latitude and longitude is one of the core findings in the adaptive evolution of plants.

Organ-Specific Transcriptome Analysis Identifies Candidate Genes Involved in the Stem Specialization of Bermudagrass (Cynodon dactylon L.)

As an important warm-season turfgrass and forage grass species with wide applications, bermudagrass (Cynodon dactylon L.) simultaneously has shoot, stolon and rhizome, three types of stems with different physiological functions. To better understand how the three types of stems differentiate and specialize, we generated an organ-specific transcriptome dataset of bermudagrass encompassing 114,169 unigenes, among which 100,878 and 65,901 could be assigned to the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Gene Ontology (GO) terms, respectively. Using the dataset, we comprehensively analyzed the gene expression of different organs, especially the shoot, stolon and rhizome. The results indicated that six organs of bermudagrass all contained more than 52,000 significantly expressed unigenes, however, only 3,028 unigenes were enrich-expressed in different organs. Paired comparison analyses further indicated that 11,762 unigenes were differentially expressed in the three types of stems. Gene enrichment analysis revealed that 39 KEGG pathways were enriched with the differentially expressed unigenes (DEGs). Specifically, 401 DEGs were involved in plant hormone signal transduction, whereas 1,978 DEGs were transcription factors involved in gene expression regulation. Furthermore, in agreement with the starch content and starch synthase assay results, DEGs encoding starch synthesis-related enzymes all showed the highest expression level in the rhizome. These results not only provided new insights into the specialization of stems in bermudagrass but also made solid foundation for future gene functional studies in this important grass species and other stoloniferous/rhizomatous plants.

Proteome analysis of bermudagrass stolons and rhizomes provides new insights into the adaptation of plant stems to aboveground and underground growth

As an important perennial warm-season turfgrass species, bermudagrass (Cynodon dactylon L.) forms underground-growing rhizomes and aboveground-growing stolons simultaneously, making it a fast propagating clonal plant with strong regeneration ability. In the current study, we compared the internode proteomes of rhizomes and stolons at the same developmental stage in the bermudagrass cultivar Yangjiang using iTRAQ. The results indicated that 228 protein species were differentially accumulated in the two specialized stems. In agreement with the different contents of starch, chlorophyll, anthocyanin and H₂O₂ in the two types of stems, photosynthesis and flavonoid biosynthesis were enriched with differentially accumulated protein species (DAPs) in stolons, whereas starch and sucrose metabolism, glycolysis, and H₂O₂ metabolism were enriched with DAPs in rhizomes. Burying stolons in the soil resulted in the gradual degradation of chlorophyll and anthocyanin, accumulation of starch, and increment of H₂O₂, which is similar to the physiological characteristics of rhizomes. These results collectively revealed that stolons and rhizomes of bermudagrass have significant differences at the proteome level and light might play important regulatory roles in the discrepancy of the proteome profiles and specialization of the two stems, providing new insights into the adaptation of plant stems to aboveground and underground growth. BIOLOGICAL SIGNIFICANCE: As two types of specialized stems that grow underground and aboveground respectively, rhizomes and stolons play important roles in overwintering and ecological invasion of many perennial and clonal plants. However, because rhizomes and stolons rarely coexist in single plant species, the differences between the two stems remain unclear at the molecular level. In this study, through an iTRAQ comparative proteomic analysis, we reported the identification of 228 differentially accumulated protein species (DAPs) in rhizomes and stolons of bermudagrass for the first time. We found that the 228 DAPs were interconnected to form protein networks in regulating diverse cellular activities and biochemical reactions. We also observed that stolons growing underground showed similar physiological activities and DAP expression as those of underground-growing rhizomes, suggesting that light might play important regulatory roles in the specialization of stolons and rhizomes. These results expanded our understanding of the mysterious adaption of plant stems to different growth conditions.

Genome Resources for Seven Fungal Isolates That Cause Dollar Spot Disease in Turfgrass, Including Clarireedia jacksonii and C. monteithiana

Fungi in the genus Clarireedia are widespread and destructive pathogens of grasses worldwide, and are best known as the causal agents of dollar spot disease in turfgrass. Here, we report genome assemblies of seven Clarireedia isolates, including ex-types of the two most widespread species, Clarireedia jacksonii and C. monteithiana. These datasets provide a valuable resource for ongoing studies of the dollar spot pathogens that include population diversity, host-pathogen interactions, marker development, and disease control.

C4 herbs dominate the reservoir flood area of the Three Gorges Reservoir

Dam operations can dramatically degenerate riparian vegetation. To improve the restoration practices of reservoir riparian vegetation, it is important to understand which and how a dominant species physiologically and ecologically maintain high fitness in this type of ecosystems. We explored the compositional change of riparian plants during the long-term flood-dry-flood cycle in the reservoir flood area (RFA) of the Three Gorges Reservoir Area (TGRA), China. In total 769 vascular plant species (belonging to 415 genera in 122 families) existed in the study area before damming (prior to 2006, i.e. the natural riparian zone). Following damming (2008-2018), plant species diversity rapidly declined, with only 51 species identified in 2018 (45 genera in 22 families). Before damming, perennial herbs, annual herbs and shrubs co-dominated the study area. After damming, the proportion of shrubs decreased significantly, and the proportion of annuals to total plants increased by 20%. Alien invasive species proportion increased from 5% to 18%. Notably, the proportion of C₄ species increased significantly from 7% to 31%. Ten of the 16 dominant species in RFA since 2015 were C₄ Poaceae species. Our study indicates that dam construction could cause severe biodiversity loss of riparian plants and draw alien species invasion. Besides, C₄ herbs would dominate the RFA. A higher photosynthetic rate could help C₄ plants grow faster to cope with the nitrogen deficiency and short growth cycles in RFA. Hence, screening C₄ herbs for vegetation restoration might aid in maintaining biodiversity and ecosystem functions in flood-dry-flood reservoir flood areas.

Potential ameliorative effect of Cynodon dactylon (L.) pers on scopolamine-induced amnesia in rats: Restoration of cholinergic and antioxidant pathways

AIM:

The present study explored Cynodon dactylon hydro-ethanolic extract (CDE) effect on scopolamine-induced amnesic rats.

MATERIALS AND METHODS:

C. dactylon extract was subjected to antioxidant (DPPH and H₂O₂) and acetylcholinesterase enzyme tests by in vitro methods. Scopolamine (1 mg/kg, i.p) was administered to rats except for normal control. Donepezil (3 mg/kg, p.o), CDE (100, 200, and 400 mg/kg p.o) were administered to treatment groups. Behavioral paradigm: Morris water maze (MWM), elevated plus maze (EPM), and passive avoidance test (PAT) were conducted. Later, rats were sacrificed and brain homogenate was tested for levels of acetylcholinesterase, glutathione, and lipid peroxidase. Histopathology examination of cortex and hippocampus of all the groups was done.

STATISTICAL METHOD:

The statistical methods used were ANOVA and Tukey's post hoc test.

RESULTS:

CDE antioxidant activity was demonstrated by decreasing DPPH and H₂O₂ levels confirmed through in vitro analysis. Treatment group rats reversed scopolamine induced amnesia by improvement in spatial memory, decreased transfer latency and increased step through latency significantly (P<0.001) in behavior models such as morris water maze, elevated plus maze and passive avoidance task respectively. CDE modulated acetylcholine transmission by decreased acetylcholinesterase enzyme level (P < 0.001) and scavenging scopolamine-induced oxidative stress by increased reduced glutathione levels and decreased lipid peroxidation levels in the rat brain. CDE and donepezil-treated rats showed mild neurodegeneration in comparison to scopolamine-induced severe neuronal damage on histopathology examination.

CONCLUSION:

C. dactylon extract provides evidence of anti-amnesic activity by the mechanism of decreased acetylcholinesterase enzyme level and increased antioxidant levels in scopolamine-induced amnesia in rats.

Response of dominant plant species to periodic flooding in the riparian zone of the Three Gorges Reservoir (TGR), China

Human-induced disturbances such as dam construction and regulation often change the duration and frequency of flooding and thus notably influence plant dominance in riparian zones. Even though numerous studies have indicated that the oxidative stress and antioxidative stress systems are essential for plant defenses against adverse flooding stress, the mechanism of vegetation distribution due to hydrological regimes is still unclear. In the current study, the riparian zone of the Three Gorges Reservoir (TGR), which experiences seasonal and anti-seasonal water-level fluctuations, was used to investigate the dominant species. To our knowledge, this is the first study that links molecular-physiological-morphological mechanisms to explore the development of flooding tolerance of dominant riparian species. Physiological traits (e.g., chlorophyll and protein contents), morphological traits (e.g., leaf length), and molecular traits (e.g., enzymatic antioxidant activity and the malondialdehyde content) were analyzed at different water-level gradient zones of the dominant species to evaluate the influence of flooding. To explore the regulation mechanisms of submergence for the vegetation distribution, correlation analysis, PCA (principal component analysis) and laboratory flooding experiments were conducted. The results showed that Cynodon dactylon, which has a rapid antioxidative system, was the dominant species in the riparian zone of the TGR. The leaf length varied significantly along with water level gradients (p < 0.05) with the minimum values appearing in the lowest part of the riparian zone and the maximum values observed in the highest areas. The chlorophyll and protein contents fluctuated in different water level gradient zones, but significant differences were not observed. Within the antioxidative system, catalase was found to be essential for riparian plants in their response to flooding. The current study could provide insight to explore the specific mechanism of resistance for dominant plants to periodic flooding, and the reason why dominant species can survive adverse stress.

Assessment of monoamine neurotransmitters in the cortex and cerebellum of gamma-irradiated mice: A neuromodulatory role of Cynodon dactylon

INTRODUCTION:

Radiation is an important tool in the diagnostic and curative treatment of many cancers. Ionizing radiation induces many biochemical changes in the cells. The present study was designed to estimate the level of neurotransmitters in the distinct brain tissue of Swiss albino mice before exposing gamma radiation.

MATERIALS AND METHODS:

The mice were treated with 0.25 and 1 g/kg body weight of Cynodon dactylon extract (CDE) via oral gavage for 7 days and subjected to 5 Gy of gamma radiation. The estimation of monoamines was performed in the cortex and cerebellum separately.

RESULTS:

Mice exposed to a sublethal dose 5 Gy of gamma radiation causes a significant decrease in dopamine, norepinephrine, epinephrine, and serotonin levels compared to normal. The mice treated with 0.25 and 1 g/kg body weight of CDE via oral gavage for 7 days showed significant improvement in the level of monoamine neurotransmitters in both the cortex and cerebellum homogenate.

CONCLUSION:

Oral administration of antioxidant-rich C. dactylon has shown a neuromodulatory effect against radiation-induced depletion of neurotransmitters in the brain tissues.

Adaptability and Comparative Biology of Fall Armyworm on Maize and Perennial Forage Species and Relation with Chemical-Bromatological Composition

This study compared the development of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), on forage species of different genera (Arachis, Axonopus, and Cynodon) in relation to maize (preferred host) as well as its adaptability on these forage species, which are the main cultivated forages in southern Brazil. The biological performance of S. frugiperda fed on host plants studied showed the highest adaptation index (AI) in maize (26.89), followed by bermudagrass (22.02), suggesting that bermudagrass is the most suitable alternative host for the development of S. frugiperda. In contrast, the giant missionary grass (18.80) and Pinto peanut (13.81) showed lower adequacy, with a relative adaptation index (RAI) 69.93 and 51.35%, respectively, using maize as standard. The cluster analysis based on similarity of the chemical-bromatological parameters showed that maize has a richer composition than the other plant species studied. The multivariate correlation analysis between AI and chemical-bromatological composition showed a positive correlation between AI and contents of ashes, ethereal extract, potassium, phosphorus, and magnesium and, to a lesser extent, with contents of nitrogen, crude protein, and copper. In this context, complexity of host composition and balance between components could explain the biological fitness of S. frugiperda on host plant species. Pasture diversification with giant missionary grass, or especially with Pinto peanut, may be an interesting strategy for integrated pest management of fall armyworm in pasturelands in a regional context.

Morphological variation in Cynodon dactylon (L.) Pers., and its relationship with the environment along a longitudinal gradient

Background

Geographical variation in morphological traits may reflect evolutionary patterns of morphological adaptability along environmental gradients. Comprehensive information on longitudinal patterns of morphological trait variation is very meaningful to explore morphological diversity and evolutionary trends in widespread bermudagrass.

Methods

To explore the spatial patterns of morphological traits, we investigated 10 morphological traits of bermudagrass and 10 soil nutrient indexes and collected local climate data for 13 different regions from 119°E to 105°E along the latitude 34°N.

Results

Considerable variations in morphological traits were observed at different longitudes, and the variations in most of the evaluated traits within populations were lower than those among populations. All of the 13 different longitudinal sites were divided into three groups based on morphological traits by cluster analysis. The major sources of diversity at the different longitudes were leaf length of the erect shoot, leaf width of the erect shoot, and the internode lengths of the erect shoot and stolon as determined by principal component analysis. Pearson correlation analysis also indicated that longitude was significantly and negatively correlated with these traits as well. Mean average rainfall was significantly correlated with leaf length of the erect shoot and the internode lengths of the erect shoot and stolon, while mean average temperature was only significantly correlated with internode length of the erect shoots. Available sulfur was significantly correlated with internode length of the erect shoot, plant height, and reproductive branch height, while the exchangeable Ca was significantly correlated with internode lengths of the erect shoot and stolon. Soil pH was significantly correlated with the internode length of the stolon. Longitude is an important factor that affects morphological trait variation in wild bermudagrass, and the leaves of the erect shoot and the internode length enlarged significantly with the collection sites moving from east to west.

Conclusion

Different combinations and interactions of environmental factors (soil and climate) along a longitudinal gradient may have strong effects on one or more morphological traits of bermudagrass.

Is Pasture Cropping a Valid Weed Management Tool

The aim of the present work was to study the feasibility of pasture cropping under the Mediterranean conditions prevailing in central Spain and its potential as a weed management tool. Three cropping systems were assessed: conventionally grown winter barley and winter barley in pasture cropping with two perennial summer species, Cynodon dactylon and Eragrostis curvula. The results showed that the growth of these two species in a pasture cropping system was limited by the severe drought conditions and high temperatures present during the summer in some of the study years. Although there were no differences in the establishment of winter barley in any of the treatments assessed, pasture cropping reduced winter barley yields up to 50%-60% in years with low rainfall in spring. Regarding weed control, pasture cropping showed a significant suppression of the total weed density and number of weed species. As a conclusion, pasture cropping can be considered as a valid weed management tool. However, the economic feasibility of this system under the climatic conditions of central Spain (characterized by a high risk of severe summer droughts) is still not clear. The availability of supplemental irrigation may reduce competition between pastures and winter crops and ensure a profitable production of summer pastures.

Regulation of estrous cycle by Cynodon dactylon in letrozole induced polycystic ovarian syndrome in Wistars albino rats

Menstrual cycle is controlled by luteinizing hormone (LH) and follicle-stimulating hormone of anterior pituitary and regulated by gonadotropin-releasing hormone of hypothalamus. Any disturbance to this regulatory mechanism alters the pulsatile release of these hormones, especially LH; leads to polycystic ovarian syndrome (PCOS). Changes in vaginal cytology are used to interpret the changes in hormonal levels and modifications in estrous cycle. The aim of this study is to compare the pattern of vaginal cytology and body mass among PCOS rats which are treated with metformin and Cynodon dactylon. Twenty-four Wistar rats were selected and divided into four groups: control, induced, treatment, and referral. PCOS was induced in all groups except controls by giving letrozole through oral gavage for 21 days. After inducing PCOS, the referral and treatment group were treated for PCOS with metformin and C. dactylon respectively for next 21 days. Vaginal smear of all the groups were taken every day from day one and screened for estrous cycle. The body mass of the animals was measured on days 1, 21, and 42. Animals were sacrificed after 24 hours of the last dose and the reproductive organs were dissected out and weighed. Results of the study show the estrous cycle begins to revert after 1-week administration of C. dactylon; while the changes were slower in referral group. There was a rapid decrease in the body mass as well as reproductive organs among the treatment and referral group compared to that of induced and control. Finding of this study suggests that C. dactylon treats PCOS better than metformin.

Cysestermerol A, a rare stilbene sestermer with significant hypoglycemic activities from Cynodon dactylon

Cysestermerol A (1), a rare and new stilbene sestermer, was isolated from the whole herb of Cynodon dactylon. The planar and relative structures of 1 were elucidated based on HRESIMS, one- and two-dimensional NMR analyses, and its absolute configuration was further established by electronic circular dichroism calculations. Compound 1 obviously increased the glucose consumption in HepG2 cells equivalent to the positive control rosiglitazone and markedly inhibited the activity of α-glucosidase in vitro.

Unbiased phosphoproteome profiling uncovers novel phosphoproteins and phosphorylation motifs in bermudagrass stolons

As a widely used turfgrass species, bermudagrass (Cynodon dactylon L.) can be easily propagated through colonial growth of stolons. Previous studies collectively revealed that exotic environmental factors and intrinsic hormones and genes are all involved in the differentiation, development, and diageotropical growth of stolons. However, the detailed molecular mechanism how environmental and hormone signals regulate the gene expression and biochemical activities in bermudagrass stolons remains unclear. In this study, we observed that reversible phosphorylation modification plays important roles in normal growth and physiological functions of bermudagrass stolons. LC-MS/MS analyses of the total protein extracts of bermudagrass stolons without preliminary phosphopeptide-enrichment successfully identified 646 nonredundant phosphorylation sites and 485 phosphoproteins. The phosphoproteins were significantly enriched in protein phosphorylation regulation and starch metabolism processes. Motif-X analyses further revealed that phosphoproteins containing novel phosphorylation motifs might be involved in transcription regulation of bermudagrass stolons. These results greatly expanded our understanding of the growth and development of bermudagrass stolons at the post-translational level.

Comparative proteomic analysis provides new insights into the specialization of shoots and stolons in bermudagrass (Cynodon dactylon L.)

Background

Bermudagrass (Cynodon dactylon L.) is an important turfgrass species with two types of stems, shoots and stolons. Despite their importance in determining the morphological variance and plasticity of bermudagrass, the intrinsic differences between stolons and shoots are poorly understood.

Results

In this study, we compared the proteomes of internode sections of shoots and stolons in the bermudagrass cultivar Yangjiang. The results indicated that 376 protein species were differentially accumulated in the two types of stems. Pathway enrichment analysis revealed that five and nine biochemical pathways were significantly enriched in stolons and shoots, respectively. Specifically, enzymes participating in starch synthesis all preferentially accumulated in stolons, whereas proteins involved in glycolysis and diverse transport processes showed relatively higher abundance in shoots. ADP-glucose pyrophosphorylase (AGPase) and pyruvate kinase (PK), which catalyze rate-limiting steps of starch synthesis and glycolysis, showed high expression levels and enzyme activity in stolons and shoots, respectively, in accordance with the different starch and soluble sugar contents of the two types of stems.

Conclusions

Our study revealed the differences between the shoots and stolons of bermudagrass at the proteome level. The results not only expand our understanding of the specialization of stolons and shoots but also provide clues for the breeding of bermudagrass and other turfgrasses with different plant architectures.

Supplementary material

Supplementary information accompanies this paper at 10.1186/s12864-019-6077-3.

Phytoavailability of potentially toxic elements from industrially contaminated soils to wild grass

Topsoil and grass samples from 14 sites located in different distances from three copper mining factories and a copper smelter were collected in Srednogorie, Bulgaria. The paper discusses results of studies on the mobility of potentially toxic elements (As, Cd, Cr, Cu, Mn, Ni, Pb, Zn) from contaminated soils to wild grass Cynodon dactylon in terms of transfer (TF: soil to plant) and phytoavailability (PF: EDTA (ethylenediaminetetraacetic acid)-soluble to plant) factors. Soils located close to mine and smelter factories were heavily contaminated by As and Cu reaching levels up to 500 mg/kg and 2400 mg/kg, respectively for As and Cu. At seven sites arsenic and copper in grass were over the normal levels (1 mg/kg As; 20 mg/kg Cu). The content of Cu in grass averaged 63 mg/kg exceeding the maximum allowable for sheep. Relationship between PF and TF values was found for As, Cd, Cu, Ni, Pb, Zn but not for Mn and Cr. To some extent the soil pH, TOM (total organic matter) and CaCO₃ content are related to the phytoavailability of As, Cd and Cu since for Zn and Pb this relation is attributed to Al- and Fe-content of soil. Statistically significant correlation coefficients were determined between the EDTA-soluble fraction of soil and content in grass in the case of As, Cd, Cr, Cu, Mn and Pb indicating the suitability of the short procedure for phytoavailability studies of those elements. The application of hierarchical cluster analysis and self-organizing maps of Kohonen made it possible to reveal specific hidden relationships between the soil variables and transfer factors as well as between the sampling locations. This additional information helps in more detailed interpretation of phytoavailability and transfer processes in the region of interest. The novelty in this study is achieved by careful consideration of the possibility of using EDTA extracts of the toxic metals in investigating of the phytoavailability and transfer processes soil/plant. Additionally, chemometric expertise used makes it possible to differentiate the behavior of each toxic metal in the processes studied. The combination of easy option for rapid extraction and intelligent data analysis gives a new perspective for contributions in explanation of the complex interactions between soils and plants when assessing pollution events in a certain environment.

Collagen-silica bio-composite enriched with Cynodon dactylon extract for tissue repair and regeneration

Development of biomaterials for tissue engineering applications is of great interest to meet the demand of different clinical requirements. The wound heal dressing biomaterials should necessarily contain well-defined therapeutic components and desirable physical, chemical and biological properties to support optimal delivery of therapeutics at the site of the wound. In this study, we developed collagen-silica wound heal scaffold incorporated with the extract of Cynodon dactylon, characterized and evaluated for its wound heal potential in vitro and in vivo against collagen (Col) and Collagen-silica (CS) scaffolds that served as controls. The prepared Collagen-Silica-Cynodon extract (CSCE) scaffold exhibits porous morphology with preferable biophysical, chemical, mechanical and mass transfer properties besides its controlled biodegradation at the wound site. Stability of CSCE was found to be better than that of native collagen due to intermolecular interactions between collagen and constituents of C. dactylon as confirmed by FTIR analysis. Notably, in vitro biocompatibility assay using DAPI and Rhodamine 123 staining demonstrated that the proliferation of NIH3T3 fibroblast cells was better for CSCE when compared to the Col and CS scaffolds. In vivo wound healing experiments with full-thickness excision wounds in wistar rat model demonstrated that the wounds treated with CSCE showed accelerated healing with enhanced collagen deposition when compared to wounds treated with Col and CS scaffolds, and these studies substantiated the efficacy of CSCE scaffold for treating wounds.

Molecular cloning and sequence variance analysis of the TEOSINTE BRANCHED1 (TB1) gene in bermudagrass [Cynodon dactylon (L.) Pers]

TEOSINTE BRANCHED1 (TB1) encodes a TEOSINTE BRANCHED1, CYCLOIDEA, and PROLIFERATING CELL FACTOR (TCP) transcription factor that represses axillary bud outgrowth and lateral branch formation in plants. Previous studies have elucidated the essential tillering regulatory roles of TB1 in many grasses, including maize and rice; however, the functions of TB1 in turf grasses remain unclear. In this study, we cloned the CdTB1 gene from bermudagrass, an important turfgrass species, and characterized the transactivation function of the CdTB1 protein. Sequencing the CdTB1 gene locus in a mini-core germplasm collection of Chinese bermudagrasses led to the successful identification of 66 SNP and 2 indel mutations in the protein-coding region as well as 28 SNP and 11 indel mutations in the promoter region. Interestingly, mutations in the C-terminal transactivation domain of the CdTB1 protein had no significant influence on the transactivation activity, whereas a novel 335-bp insertion mutation located in the promoter region could significantly increase the expression of the CdTB1 gene. Furthermore, wild accessions of bermudagrass harboring the novel insertion mutation were found to have significantly reduced tillers compared with other accessions, suggesting a negative correlation between the mutation and tillering. The results of this study not only expanded our knowledge of TB1 gene expression regulation but also provided possible molecular markers to breed cultivars of turf and forage grasses with specific architectural features.

Variations in morphological traits of bermudagrass and relationship with soil and climate along latitudinal gradients

Background

This complex environmental heterogeneity coupled with the long-standing history offers scenario suitable for and favoring the evolution and existence of variation of morphological traits.

Methods

In this study, we measured 10 morphological traits of 310 Cynodon dactylon individuals sampled at 16 different locations along latitudinal gradients between 22°35′N and 36°18′N to reveal phenotypic plasticity influenced by latitude. In addition, the relationships between morphological variation and soil nutrient and climate factors were analyzed.

Results

Analysis of variance, divesity examination and Mantel correlation test detected a significant effect of latitude on morphological traits. Cluster analysis and principal component analysis clearly separated the selected populations into four groups according to latitude. Larger morphological sizes of C. dactylon appeared at the low- and high-latitude regions. Correlation analysis indicated that high morphological variations were significantly correlated with climate factors and soil nutrient.

Conclusion

This study suggests morphological variation of wild bermudagrass is greatly influenced by latitude as well as soil and climate, which could be useful resources for genetic studies and evolution.

Changes in Arsenic, Copper, Iron, Manganese, and Zinc Levels Resulting from the Application of Poultry Litter to Agricultural Soils

Twelve applications of poultry litter were made to a 2.1-ha field located in the Shenandoah Valley of Virginia, United States (USA), between March 1999 and August 2014. The field was planted with bermudagrass (Cynodon dactylon) and used as a pasture on an active farm. Copper, iron, manganese, zinc, and arsenic concentrations in the poultry litter were measured, and the application rates of these metals were calculated. The median application rates were: Cu, 1.32 kg/ha, Fe, 5.57 kg/ha, Mn, 1.80 kg/ha, Zn, 1.39 kg/ha, and As, 0.011 kg/ha. Twelve surface and subsurface soil samples were taken from the treated field in February 2016. Twelve samples were also taken from a comparison site. The comparison site was directly adjacent to the study site, consisted of the same soil type, and had been maintained as an undisturbed forest. Extractable Cu, Fe, Mn, Zn, and As concentrations in the soil samples were determined by atomic absorption spectroscopy, and the results of the chemical analysis were analyzed by ANOVA. Fe and Mn were depleted from the soil in the treated field, while Cu and Zn levels increased over the 12 years of treatment and grazing, and arsenic levels were unchanged in both the surface and subsurface soils between the comparison and the study site. The changes observed for Cu, Fe, Mn, and Zn are within the critical deficiency level and critical toxicity level for these metals, and no arsenic remains in the soil from roxarsone feed supplements, which were added to the poultry feed when the litter was applied to the study site.

In Vitro Antilithiatic Potential of Kalanchoe pinnata, Emblica officinalis, Bambusa nutans, and Cynodon dactylon

OBJECTIVE

The study aims at the exploration of calcium oxalate (CaOx) crystal growth inhibition potential of Cynodon dactylon, Emblica officinalis, Kalanchoe pinnata, and Bambusa nutans ethyl acetate fraction rich in polyphenol and flavonoid.

MATERIALS AND METHODS

Ethyl acetate fraction was separated from the hydromethanolic extract of C. dactylon, E. officinalis, K. pinnata, and B. nutans followed by quantitative analysis for total polyphenol and flavonoid content. Ethyl acetate fraction of all the plants were subjected to in vitro screening for the inhibition of CaO x crystals growth induced by sodium oxalate.

RESULTS

The results signify rich presence of polyphenols and flavonoids in K. pinnata and E. officinalis ethyl acetate fractions followed by C. dactylon and B. nutans. Ethyl acetate fractions of B. nutans shoot, E. officinalis fruit, and K. pinnata leaf have excellent in vitro CaO x crystal growth inhibition potential based on both the comparative concentration and the time level to achieve IC50.

CONCLUSION

The study outcome substantiates potential in vitro CaO x crystal dissolution and crystal growth inhibition properties of E. officinalis, B. nutans, C. dactylon, and K. pinnata. Rich presence of caffeic acid, ferulic acid, and luteolin in ethyl acetate fraction of B. nutans leaf, and chebulinic acid, chebulagic acid, gallic acid, ellagic acid, and quercetin of E. officinalis may have produced prominent crystal aggregation inhibition response.

Evaluation of Cynodon dactylon for wound healing activity

BACKGROUND AND AIMS

Research in the field of wound healing is very recent. The concept of wound healing is changing from day to day. Ayurveda is the richest source of plant drugs for management of wounds and Cynodon dactylon L. is one such. The plant is used as hemostatic and wound healing agent from ethnopharmacological point of view. Aim of the present study is scientific validation of the plant for wound healing activity in detail.

MATERIALS AND METHODS

Aqueous extract of the plant was prepared and phytochemical constituents were detected by HPLC analysis. Acute and dermatological toxicity study of the extract was performed. Pharmacological testing of 15% ointment (w/w) of the extract with respect to placebo control and standard comparator framycetin were done on full thickness punch wound in Wister rats and effects were evaluated based on parameters like wound contraction size (mm²), tensile strength (g); tissue DNA, RNA, protein, hydroxyproline and histological examination. The ointment was applied on selected clinical cases of chronic and complicated wounds and efficacy was evaluated on basis of scoring on granulation, epithelialization, vascularity as well as routine hematological investigations.

RESULTS

Significant results (p<0.05) were observed both in pharmacological and clinical studies.

CONCLUSION

The present research with aqueous extract of Cynodon dactylon explores its potential wound healing activity in animal model and subsequent feasibility in human subjects. Phenolic acids and flavonoids present in c. dactylon supports its wound healing property for its anti-oxidative activity that are responsible for collagenesis.

Anti-atherosclerotic effect of Cynodon dactylon extract on experimentally induced hypercholesterolemia in rats

Cynodon dactylon (Bermuda grass) is a perennial plant traditionally used as an herbal medicine in many countries. In the present study, anti-atherosclerotic property of ethanolic extract of C. dactylon was investigated in the experimentally induced hypercholesterolemia in rats. In this study, 36 male Wistar rats were selected and allocated into six groups (n = 6). The control group received a normal diet, sham group received a high cholesterol diet (HCD; 1.50% cholesterol and 24.00% fat) and other groups received a HCD and ethanolic extract of C. dactylon at low (100 mg kg^-1), moderate (200 mg kg^-1) and maximum (400 mg kg^-1) doses via gavages. The last group received atorvastatin (10 mg kg^-1) through gavage with a HCD. The study period for all groups was six months. At the end of this period, parameters including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were assessed in the blood samples. Additionally, histopathological and immunohistochemical examinations on coronary and aorta arteries sections were performed. The results showed an increase in vessels wall thickness and proliferation of smooth muscle cells in the HCD group, while these pathological changes were not seen in C. dactylon-treated groups. Treatment of HCD animals with C. dactylon positively changed lipid profile by lowering of TC, TG and LDL-C. The results indicate that C. dactylon prevents from early atherosclerotic changes in the vessels wall.

Photosynthesis, antioxidant system and gene expression of bermudagrass in response to low temperature and salt stress

There is widespread distribution of salinized lands in northern China. Harnessing such land is essential to environmental health. Bermudagrass [Cynodon dactylon (L.) Pers.] has the potential to improve the salinized lands. However, low temperature remarkably limits the growth of bermudagrass in winter. Currently, there is no information about the interaction of cold and salt in this plant. Hence, the objectives of this study were to figure out the effects of combined cold and salinity stress on bermudagrass. In this study, 4 °C and 200 mM salt solution was used as cold and salt treatments respectively while 4 °C along with 200 mM salt solution were applied as combined stress. After 5 days treatment, bermudagrass displayed a dramatic decline in the turf quality and chlorophyll content, but higher malonaldehyde, electrolyte leakage, hydrogen peroxide content, antioxidant enzyme activity in the combined stress regime as compared to cold or salt treated alone. Analysis of chlorophyll a revealed that the combined stress aggravated stress-induced inhibition of photosystem II. In addition, the expressions of stress-related genes were up-regulated with a lower expression level when cold and salt applied together. In summary, the grass exposed to combined stress presented a relatively lower stress tolerance and suffered a more severe damage than grass grown in the other regimes. These findings are crucial for elucidating the molecular mechanisms of cold and salt combined stress in bermudagrass, and provide information for breeding programs to select and develop bermudagrass cultivars that are suitable for improvement of the northern China salinized land.

Anti-chikungunya activity of luteolin and apigenin rich fraction from Cynodon dactylon

OBJECTIVE

To obtain luteolin and apigenin rich fraction from the ethanolic extract of Cynodon dactylon (L.) (C. dactylon) Pers and evaluate the fraction's cytotoxicity and anti-Chikungunya potential using Vero cells.

METHODS

The ethanolic extract of C. dactylon was subjected to silica gel column chromatography to obtain anti-chikungunya virus (CHIKV) fraction. Reverse phase-HPLC and GC-MS studies were carried out to identify the major phytochemicals in the fraction using phytochemical standards. Cytotoxicity and the potential of the fraction against CHIKV were evaluated in vitro using Vero cells. Reduction in viral replication was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) after treating the viral infected Vero cells with the fraction.

RESULTS

Reverse Phase-HPLC and GC-MS studies confirmed the presence of flavonoids, luteolin and apigenin as major phytochemicals in the anti-CHIKV ethanolic fraction of C. dactylon. The fraction was found to exhibit potent viral inhibitory activity (about 98%) at the concentration of 50 µg/mL as observed by reduction in cytopathic effect, and the cytotoxic concentration of the fraction was found to be 250 µg/mL. RT-PCR analyses indicated that the reduction in viral mRNA synthesis in fraction treated infected cells was much higher than the viral infected control cells.

CONCLUSIONS

Luteolin and apigenin rich ethanolic fraction from C. dactylon can be utilized as a potential therapeutic agent against CHIKV infection as the fraction does not show cytotoxicity while inhibiting the virus.

Identification and determination of flavonoids, carotenoids and chlorophyll concentration in Cynodon dactylon (L.) by HPLC analysis

Cynodon dactylon (L.) is a potent medicinal plant in the traditional and current Indian medicinal systems. The objective of this research was to find out the levels of flavonoids, carotenoids and chlorophyll b in C. dactylon leaves by high-performance liquid chromatography (HPLC) equipped with a diode array detector. HPLC analysis revealed that total carotenoid and total flavonoid concentration were 62 mg/100 g and 249.1 μg/g, respectively. The mean chlorophyll b was 85.1 mg/100 g in C. dactylon. Among the flavonoids, quercetin (164.7 μg/g) was the major flavonoid followed by kaempferol (48.2 μg/g), rutin (18.4 μg/g), catechin (12.1 μg/g) and myricetin (5.7 μg/g). Of the carotenoids, β-carotene (35.2 mg/100 g) was predominant followed by lutein (17.0 mg/100 g), violaxanthin (5.8 mg/100 g) and zeaxanthin (4.2 mg/100 g). Chlorophyll b concentration was 85.1 mg/100 g in C. dactylon. The results of this investigation should be useful information for further pharmacological studies.

Field efficacy of furfural as a nematicide on turf

A commercial formulation of furfural was recently launched in the United States as a turfgrass nematicide. Three field trials evaluated efficacy of this commercial formulation on dwarf bermudagrass putting greens infested primarily with Belonolaimus longicaudatus, Meloidogyne graminis, or both these nematodes, and in some cases with Mesocriconema ornatum or Helicotylenchus pseudorobustus. In all these trials, furfural improved turf health but did not reduce population densities of B. longicaudatus, M. graminis, or the other plant-parasitic nematodes present. In two additional field trials, efficacy of furfural at increasing depths in the soil profile (0 to 5 cm, 5 to 10 cm, and 10 to 15 cm) against B. longicaudatus on bermudagrass was evaluated. Reduction in population density of B. longicaudatus was observed in furfural-treated plots for depths below 5 cm on several dates during both trials. However, no differences in population densities of B. longicaudatus were observed between the furfural-treated plots and the untreated control for soil depth of 0 to 5 cm during either trial. These results indicate that furfural applications can improve health of nematode-infested turf and can reduce population density of plant-parasitic nematodes in turf systems. Although the degree to which turf improvement is directly caused by nematicidal effects is still unclear, furfural does appear to be a useful nematode management tool for turf.

Factors affecting furfural as a nematicide on turf

Recently a furfural nematicide Multiguard Protect EC was launched for use on turfgrasses in the United States. A series of greenhouse experiments were conducted to determine the concentration and exposure time required for this formulation to irreversibly affect Belonolaimus longicaudatus, and to study factors that might affect the practicality of furfural use in turfgrass systems. One experiment exposed B. longicaudatus to increasing concentrations of furfural (0 to 990 ppm) in vitro for either 24 or 48 hr, followed by inoculation onto bermudagrass. A second experiment evaluated effects of exposure of B. longicaudatus to increasing concentrations of furfural in soil solution on bermudagrass with or without an organic thatch layer. A third experiment evaluated effects on B. longicaudatus of increasing concentrations of furfural applied as a spray treatment to creeping bentgrass. Results from the in vitro exposure experiment found decreasing numbers of B. longicaudatus with increasing furfural concentration beginning with the lowest concentration tested (270 ppm). Belonolaimus longicaudatus were virtually eliminated with furfural concentrations ≥ 720 ppm. Similarly, exposure to increasing concentration of furfural in soil solution resulted in increasing reduction in numbers of B. longicaudatus. Presence of thatch slightly reduced the population density of B. longicaudatus. Spray application of furfural only reduced numbers of B. longicaudatus at the two highest rates (3,600 and 4,950 ppm).

Interaction Between Belonolaimus longicaudatus and Helicotylenchus pseudorobustus on Bermudagrass and Seashore Paspalum Hosts

Belonolaimus longicaudatus and Helicotylenchus pseudorobustus are among the most common nematode parasites of turfgrasses in Florida. Bermudagrass (Cynodon dactylon × C. transvaalensis) and seashore paspalum (Paspalum vaginatum) are the two turf species most commonly used on Florida golf courses. This paper explores the interactions between B. longicaudatus and H. pseudorobustus on bermudagrass and seashore paspalum hosts. Data collected from thousands of nematode samples submitted to the Florida Nematode Assay Lab over a 8-yr period revealed a negative relationship between B. longicaudatus and H. pseudorobustus on bermudagrass, but not seashore paspalum. In a multi-year field plot experiment using multiple cultivars of bermudagrass, and seashore paspalum B. longicaudatus and H. pseudorobustus were negatively related on both turf species. Greenhouse trials where multiple cultivars of both turf species were inoculated with different combinations of B. longicaudatus and H. pseudorobustus found that each nematode species was inhibitory to the other on both host species. Belonolaimus longicaudatus and H. pseudorobustus clearly impact each other on turfgrass hosts, although the mechanism of the nematode-nematode interactions is unknown.

Secondary metabolites of Cynodon dactylon as an antagonist to angiotensin II type1 receptor: Novel in silico drug targeting approach for diabetic retinopathy

OBJECTIVES

To study the ability of the secondary metabolites of Cynodon dactylon to serve as an antagonist to angiotensin II type 1 receptor (AT(1)); activation of this receptor plays a vital role in diabetic retinopathy (DR).

MATERIALS AND METHODS

In silico methods are mainly harnessed to reduce time, cost and risk associated with drug discovery. Twenty-four compounds were identified as the secondary metabolites of hydroalcoholic extract of C. dactylon using the GCMS technique. These were considered as the ligands or inhibitors that would serve as an antagonist to the AT(1). The ACD/Chemsketch tool was used to generate 3D structures of the ligands. A molecular file format converter tool was used to convert the generated data to the PDB format (Protein Data Bank) and was used for docking studies. The AT(1) structure was retrieved from the Swissprot data base and PDB and visualized using the Rasmol tool. Domain analysis was carried from the Pfam data base; following this, the active site of the target protein was identified using a Q-site finder tool. The ability of the ligands to bind with the active site of AT(1) was studied using the Autodocking tool. The docking results were analyzed using the WebLab viewer tool.

RESULTS

Sixteen ligands showed effective binding with the target protein; diazoprogesteron, didodecyl phthalate, and 9,12-octadecadienoyl chloride (z,z) may be considered as compounds that could be used to bind with the active site sequence of AT(1).

CONCLUSIONS

The present study shows that the metabolites of C. dactylon could serve as a natural antagonist to AT(1) that could be used to treat diabetic retinopathy.

Effects of Cynodon dactylon on Stress-Induced Infertility in Male Rats

Cynodon dactylon (Family: Poaceae) is known to be a tackler in Indian mythology and is offered to Lord Ganesha. It is found everywhere, even on waste land, road side, dry places, and spreads vigorously on cultivated ground. This study was carried out with an objective to test if the constituents of this plant are useful in coping stress-induced sexual In this study, we considered immobilization stress to induce male infertility and the effect of C. dactylon in restoration of the dysfunction was evaluated by considering sexual behavioral observations, sexual performance, fructose content of the seminal vesicles, epididymal sperm concentration and histopathological examinations as parameters. Treatment of rats under stress with methanolic extract of C. dactylon has shown a promising effect in overcoming stress-induced sexual dysfunction, sexual performance, fructose content, sperm concentration and its effect on accessory sexual organs and body weight. We conclude that active constituents of C. dactylon present in methanolic extract have a potent aphrodisiac and male fertility activity.

Curative effect of Cynodon dactylon against STZ induced hepatic injury in diabetic rats

The aim of the study was to ascertain the role of ethanolic extract of Cynodon dactylon against hepatic complications in streptozotocin (STZ) induced type 2 diabetic models. Effect of the pre identified most effective dose of 500 mg/kg body weight was studied on hepatic injury caused by chemically induced diabetes by 55 mg/kg body weight i.p. injection of STZ in male Wistar rats. The dose of 500mg/kg body weight given once daily for 14 days reduced the levels of serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, alkaline phosphatase, creatinine and urine sugar significantly (P<0.05) with increase in total protein, haemoglobin and body weight was increased. High LD(50) validates its high margin of safety.