Plants — Open Access Journal

Stem mustard is a stem variety of mustard, an important Brassica vegetable. The formation and development of the tumorous stem, which is the key organ for the direct yield and quality, is a complex biological process involving morphogenesis, material accumulation and gene regulation. In this study, we demonstrated through anatomical studies that stem swelling is mainly dependent on the increase in the number of cells and the volume of parenchyma cells in the cortex and pith. To further understand transcript and metabolic changes during stem swelling, we obtained 27,901 differentially expressed genes, of which 671 were specifically detected using transcriptome sequencing technology in all four stages of stem swelling. Functional annotation identified enrichment for genes involved in photosynthesis, energy metabolism, cell growth, sulfur metabolism and glucosinolate biosynthesis. Glucosinolates are a group of nitrogen- and sulfur-containing secondary metabolites, which largely exist in the Cruciferous vegetables. HPLC analysis of the contents and components of glucosinolates in four different stem development stages revealed eight glucosinolates, namely, three aliphatic glucosinolates (sinigrin, glucoalyssin and gluconapin), four indole glucosinolates (4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin and neoglucobrassicin) and one aromatic glucosinolate (gluconasturtiin). All these types of glucosinolates showed a significant downward trend during the stem swelling period. The content of aliphatic glucosinolates was the highest, with sinigrin being the main component. In addition, qPCR was used to validate the expression of nine genes involved in glucosinolate biosynthesis. Most of these genes were down-regulated during stem swelling in qPCR, which is consistent with transcriptome data. These data provide a basic resource for further molecular and genetic research on Brassica juncea. Full article

Many strains of Trichoderma fungi have beneficial effects on plant growth and pathogen control, but little is known about the importance of plant genotype, nor the underlying mechanisms. We aimed to determine the effect of sugar beet genotypic variation on Trichoderma biostimulation. The effect of Trichoderma afroharzianum T22 on sugar beet inbred genotypes were investigated in soil and on sterile agar medium regarding plant growth, and by quantitative reverse transcriptase-linked polymerase chain reaction (qRT-PCR) analysis for gene expression. In soil, T22 application induced up to 30% increase or decrease in biomass, depending on plant genotype. In contrast, T22 treatment of sterile-grown seedlings resulted in a general decrease in fresh weight and root length across all sugar beet genotypes. Root colonization of T22 did not vary between the sugar beet genotypes. Sand- and sterile-grown roots were investigated by qRT-PCR for expression of marker genes for pathogen response pathways. Genotype-dependent effects of T22 on, especially, the jasmonic acid/ethylene expression marker PR3 were observed, and the effects were further dependent on the growth system used. Thus, both growth substrate and sugar beet genotype strongly affect the outcome of inoculation with T. afroharzianum T22. Full article

We have succeeded in selecting four higher yield mutants from five gamma-ray irradiated high-yielding Japanese rice varieties using a novel approach. A total of 464 M₂ plants which had heavier total panicle weights per plant were first selected from 9801 irradiated M₂ plants. Their higher yields were confirmed by yield trials conducted for three years with a six to ten-pairwise replicated plot design. FukuhibikiH6 and FukuhibikiH8 were selected from an irradiated high-yielding variety Fukuhibiki and showed 1.2% to 22.5% higher yield than their original significantly. YamadawaraH3 was selected from an irradiated high-yielding variety Yamadawara and its yield advantages were 2.7% to 3.9%. However, there was no difference in the genotypes of the 96 SNP (single nucleotide polymorphism) markers between the higher yield mutants and their respective original varieties. The differences in the measured phenotypical traits between each mutant and its original variety were not constant and the actual differences were marginal. Therefore, the higher yields of the selected mutants were likely to have been caused by physiological traits rather than phenotypical traits. The selection method used in this study is an application of the directed evolution method which has long been commonly used in the substantial improvements of microorganisms and their proteins. Full article

This study aimed to assess effect of nitrogen (N) form and phosphorus (P) level on the growth and mineral composition of hybrid Napier grass. Experimental plants were grown with different N forms (NO₃⁻, NH₄NO₃, and NH₄⁺; 500 µM) and P concentrations (100 and 500 µM) under greenhouse conditions for 42 days. Growth rate, morphology, pigments, and mineral nutrients in the plant tissue were analysed. At the low P concentration, the better growth was found in the plants supplied with NH₄⁺ (relative growth rate (RGR) = 0.05 g·g⁻¹·d⁻¹), but at the high P concentration, the NH₄⁺-fed plants had 37% lower growth rates and shorter roots and stems. At the high P level, the NH₄NO₃⁻-fed plants had the highest RGR (0.04 g·g⁻¹·d⁻¹). The mineral nutrient concentrations in the plant tissues were only slightly affected by N form and P concentration, although the P concentrations in the plant tissue of the NO₃⁻-fed plants supplied with the high P concentration was 26% higher compared to the low P concentration plants. The N concentrations in the plant tissues did not vary between treatments. The results showed that the optimum N form for the plant growth and biomass productivity of hybrid Napier grass depends on P level. Hybrid Napier grass may be irrigated by treated wastewater containing high concentrations of N and P, but future studies are needed to evaluate biomass production and composition when irrigating with real wastewater from animal farms. Full article

Heavy metals in soil, as selective agents, can change the structure of plant-associated bacterial communities and their metabolic properties, leading to the selection of the most-adapted strains, which might be useful in phytoremediation. Trifolium repens, a heavy metal excluder, naturally occurs on metal mine waste heaps in southern Poland characterized by high total metal concentrations. The purpose of the present study was to assess the effects of toxic metals on the diversity and metabolic properties of the microbial communities in rhizospheric soil and vegetative tissues of T. repens growing on three 70–100-years old Zn–Pb mine waste heaps in comparison to Trifolium-associated bacteria from a non-polluted reference site. In total, 113 cultivable strains were isolated and used for 16S rRNA gene Sanger sequencing in order to determine their genetic affiliation and for in vitro testing of their plant growth promotion traits. Taxa richness and phenotypic diversity in communities of metalliferous origin were significantly lower (p < 0.0001) compared to those from the reference site. Two strains, Bacillus megaterium BolR EW3_A03 and Stenotrophomonas maltophilia BolN EW3_B03, isolated from a Zn–Pb mine waste heap which tested positive for all examined plant growth promoting traits and which showed co-tolerance to Zn, Cu, Cd, and Pb can be considered as potential facilitators of phytostabilization. Full article

The current study on the traditional use of medicinal plants was carried out from February 2018 to March 2020, in Gokand Valley, District Buner, Pakistan. The goal was to collect, interpret, and evaluate data on the application of medicinal plants. Along with comprehensive notes on individual plants species, we calculated Use Value (UV), Relative Frequency of Citation (RFC), Use Report (UR), Fidelity Level (FL), Informant Consensus Factor (FCI), as well as Family Importance Value (FIV). During the current study, a total of 109 species belonging to 64 families were reported to be used in the treatment of various ailments. It included three families (four species) of Pteridophytes, 58 families (99 species) of angiosperm, one family (three species) of Gymnosperms, and two families (three species) of fungi. The article highlights the significance of domestic consumption of plant resources to treat human ailments. The UV varied from 0.2 (Acorus calamus L.) to 0.89 (Acacia modesta Wall.). The RFC ranged from 0.059 (Acorus calamus L. and Convolvulus arvensis L.) to 0.285 (Acacia modesta Wall.). The species with 100% FL were Acacia modesta Wall. and the fungus Morchella esculenta Fr., while the FCI was documented from 0 to 0.45 for gastro-intestinal disorders. The conservation ranks of the medicinal plant species revealed that 28 plant species were vulnerable, followed by rare (25 spp.), infrequent (17 spp.), dominant (16 spp.), and 10 species endangered. The traditional use of plants needs conservation strategies and further investigation for better utilization of natural resources. Full article

Artemisia arborescens is an aromatic shrub whose essential oils are considered a potential source of molecules with industrial and pharmaceutical interest. The chemical profile of A. arborescens essential oils (EOs) was shown to be quite variable and various chemotypes have been identified. In this study, we compared the EOs composition of A. arborescens leaves and flowers collected from four different locations in Sicily. The EOs were assayed for their antiproliferative activity against A375 human malignant melanoma cells, also testing cell viability and cell membrane integrity. The evaluation of DNA fragmentation and caspase-3 activity assay was employed for the detection of apoptosis. The expression of Bcl-2, Bax, cleaved caspase-9, PTEN (Phosphatase and tensin homolog), Hsp70 (Heat Shock Protein 70 kilodaltons) and SOD (superoxide dismutase) proteins was evaluated by Western blot analysis. The levels of ROS and GSH were also analyzed. Results show that EOs presented significant differences in their composition, yield, and cytotoxic activity depending on the collection site. The chamazulene/camphor-rich EOs from plants collected in Acqua Calda (Lipari) resulted particularly active on melanoma cancer cells (IC₅₀ values of 6.7 and 4.5 µg/mL), being able to trigger apoptotic death probably interfering with endogenous defense mechanisms. These oils may be considered as a natural resource of chamazulene, containing this compound up to 63%. Full article

The nonexpressor of pathogenesis-related 1 (NPR1) family plays diverse roles in gene regulation in the defense and development signaling pathways in plants. Less evidence is available regarding the significance of the NPR1-like gene family in cotton (Gossypium species). Therefore, to address the importance of the cotton NPR1-like gene family in the defense pathway, four Gossypium species were studied: two tetraploid species, G.hirsutum and G. barbadense, and their two potential ancestral diploids, G. raimondii and G. arboreum. In this study, 12 NPR1-like family genes in G. hirsutum were recognized, including six genes in the A-subgenome and six genes in the D-subgenome. Based on the phylogenetic analysis, gene and protein structural features, cotton NPR-like proteins were grouped into three different clades. Our analysis suggests the significance of cis-regulatory elements in the upstream region of cotton NPR1-like genes in hormonal signaling, biotic stress conditions, and developmental processes. The quantitative expression analysis for different developmental tissues and fiber stages (0 to 25 days post-anthesis), as well as salicylic acid induction, confirmed the distinct function of different cotton NPR genes in defense and fiber development. Altogether, this study presents specifications of conservation in the cotton NPR1-like gene family and their functional divergence for development of fiber and defense properties. Full article

Invasive species are considered as one of the major threats to ecosystems worldwide. Although invasive plants are regarded as a foe, they could be considered as natural resources for valuable bioactive compounds. The present study aimed to characterize the chemical composition of the essential oil (EO) from the invasive plant Argemone ochroleuca Sweet, collected from Saudi Arabia, as well as to evaluate its phytotoxic activity. Seventy-four compounds were characterized via GC-MS analysis of EO representing 98.75% of the overall mass. The oxygenated constituents (79.01%) were found as the main constituents, including mono- (43.27%), sesqui- (17.67%), and di-terpenes (0.53%), as well as hydrocarbons (16.81%) and carotenoids (0.73%). Additionally, 19.69% from the overall mass was characterized as non-oxygenated compounds with mono- (1.77%), sesquiterpenes (17.41%), and hydrocarbons (0.56%) as minors. From all identified constituents, trans-chrysanthenyl acetate (25.71%), γ-cadinene (11.70%), oleic acid, methyl ester (7.37%), terpinene-4-ol (4.77%), dihydromyrcenol (2.90%), α-muurolene (1.77%), and γ-himachalene (1.56%) were found as abundant. The EO of A. ochroleuca showed significant phytotoxic activity against the test plant Lactuca sativa and the noxious weed Peganum harmala. The EO attained IC₅₀ values of 92.1, 128.6, and 131.6 µL L⁻¹ for seedling root growth, germination, and shoot growth of L. sativa, respectively, while it had IC₅₀ values of 134.8, 145.7, and 147.9 µL L⁻¹, respectively, for P. harmala. Therefore, this EO could be used as a bioherbicide against weeds, while further study is recommended for the characterization of the authentic materials of the main compounds in the EO as well as for the evaluation of potency of this oil on a field scale and the determination of its biosafety. Full article

Magnolia lucida (Magnoliaceae) is classified as an endangered species by the International Union for Conservation of Nature. It has high commercial value owing to its attractive tree shape and flowers. We adopted an excellent genotype of M. lucida as the parent material and established a mini-cut orchard through grafting to provide trunk shoots explants over the long-term. Optimal sterilization was achieved using a combination of 75% ethanol for 30 s, one percent benzalkonium bromide for five minutes, and 0.1% mercuric chloride for five minutes. Modified Murashige and Skoog medium (ML) was the optimal medium for the growth of M. lucida. Addition of one mg/L of 6-benzyl adenine (BA) and 0.05 mg/L of α-naphthaleneacetic acid (NAA) to the medium increased the shoot induction rate to 95.56%, and the ML medium containing 0.4 mg/L BA and 0.04 mg/L NAA achieved the maximum multiplication rate (284.56%). Dark treatment for seven days, followed by continuous light treatment could better resolve the challenge of difficult rooting in M. lucida plants. Using random amplified polymorphic DNA and inter simple sequence repeat markers, we confirmed the genetic uniformity and stability of the regenerated plants. Our protocol should be helpful for the propagation and conservation of this endangered plant. Full article

White clover (Trifolium repens L.) is a widely cultivated cool-season perennial forage legume in temperate grassland systems. Many studies have analyzed the gene expression in this grass species using quantitative real-time reverse transcription PCR (qRT-PCR). The selection of stable reference genes for qRT-PCR is crucial. However, there was no detailed study on reference genes in different tissues of white clover under various abiotic stress conditions. Herein, 14 candidate reference genes (ACT7, ACT101, TUA1109, TUB, CYP, 60SrRNA, UBQ, E3, GAPDH1, GAPDH2, PP2A, BAM3, SAMDC, and ABC) were selected and analyzed by four programs (GeNorm, NormFinder, BestKeeper, and RefFinder). Samples were taken from two tissues (leaves and roots) under five different abiotic stresses (drought, salt, heat, cold, and heavy metal stress). Our results showed that 60SrRNA and ACT101 were the two top-ranked genes for all samples. Under various experimental conditions, the most stable gene was different; however, SAMDC, UBQ, 60SrRNA, and ACT101 were always top ranked. The most suitable reference genes should be selected according to different plant tissues and growth conditions. Validation of these reference genes by expression analysis of Cyt-Cu/Zn SOD and CAT confirmed their reliability. Our study will benefit the subsequent research of gene function in this species. Full article

Alfalfa (Medicago sativa L.) is a major forage crop of family Fabaceae and is frequently cultivated in Egypt. The present study is concerned with the genetic discrimination of fifteen alfalfa cultivars from three different countries (Egypt, Australia, and USA) using two molecular approaches: inter-retrotransposon-amplified polymorphism (IRAP) markers and two chloroplast DNA barcodes matK and the trnH in addition to the analysis of fifteen morpho-agronomic traits. The genetic relatedness, based on analysis of IRAP marker polymorphism and produced using eleven primers by clustering via principal component analysis (PCA) and multivariate heatmap biostatistical methods differentiated the two Egyptian cultivars EGY1-Ismailia1 and EGY2-Nubaria1 from the three Australian and seven American cultivars, with some distinction of the cv. USA6-SW9720 and cv. AUS4-SuperFast. The results were also supported by the sequence analysis of the matK and the trnH genes on the genetic relatedness between eight cultivars. Moreover, it might be suggested that breeding lines from M. sativa cultivars may provide novel insights and a better understanding of the domestication of M. sativa genetic diversity. The classification of the eight cultivars, as revealed by morpho-agronomic traits, confirmed the close genetic relationship between the two Egyptian cultivars and indicated some resemblance between them and the AUS2-Siri Nafa, whereas the two American cultivars, USA1-Super supreme and USA4-Cuf101, were clearly isolated from a cluster of other three cultivars USA7-SW9628, USA8-Magna901, and USA9-Perfect. The results are useful sources of genetic information for future breeding programs in crop development and open new possibilities of producing M. sativa lines harboring high forage quality, productivity, and resistance to biotic and abiotic stresses. Full article

The essential oils (EOs) of three Caprifoliaceae species, the Eurasiatic Valeriana officinalis (Vo), the Himalayan Valeriana jatamansi (Vj) and Nardostachys jatamansi (Nj), are traditionally used to treat neurological disorders. Roots/rhizomes micromorphology, DNA barcoding and EOs phytochemical characterization were carried out, while biological effects on the nervous system were assessed by acetylcholinesterase (AChE) inhibitory activity and microelectrode arrays (MEA). Nj showed the highest inhibitory activity on AChE (IC₅₀ 67.15 μg/mL) followed by Vo (IC₅₀ 127.30 μg/mL) and Vj (IC₅₀ 246.84 μg/mL). MEA analyses on rat cortical neurons, carried out by recording mean firing rate (MFR) and mean bursting rate (MBR), revealed stronger inhibition by Nj (IC₅₀ 18.8 and 11.1 μg/mL) and Vo (16.5 and 22.5 μg/mL), compared with Vj (68.5 and 89.3 μg/mL). These results could be related to different EO compositions, since sesquiterpenes and monoterpenes significantly contribute to the observed effects, but the presence of oxygenated compounds such as aldehydes and ketones is a discriminating factor in determining the order of potency. Our multidisciplinary approach represents an important tool to avoid the adulteration of herbal drugs and permits the evaluation of the effectiveness of EOs that could be used for a wide range of therapeutic applications. Full article

Purple seed stain disease, caused by (Cercospora kukuchii), is a major concern in soybean (Glycine max (L.)) in Mississippi, USA, due to its effects on seed quality, reducing soybean seed grade and potential market price at elevators. Therefore, investigating the effects of purple seed stain (PSS) on seed quality (germination and vigor) and seed composition (nutrition) is critical. The objective of this study was to investigate the effects of PSS on seed harvest index, seed germination, seed vigor, and seed composition components (protein, oil, fatty acids, and sugars). A field experiment was initiated in 2019 in Stoneville, MS, at the Delta Research and Extension Center (DREC) on a Commerce silt loam soil (fine-silty, mixed, superactive, nonacid, thermic Fluventic Epiaquepts). Soybean variety Credenz 4748 LL was used. The results showed that infected (symptomatic) seed had a 5.5% greater Seed Index (based on 100 seed weight) when compared to non-infected (non-symptomatic, as control) seed. Non-infected seed had greater percent germination and seedling vigor when compared to infected seed. Germination was 30.9% greater and vigor was 58.3% greater in non-infected seed. Also, the results showed that infected seed with PSS had higher protein content and some amino acids. No changes in total oil and fatty acids. Sucrose and stachyose were lower in infected seed than in non-infected seed. The research showed that PSS impacted seed health and seed quality (germination and vigor) and seed composition (protein, sugars, and some amino acids). Purple stained seed should be avoided when planting and should be managed properly as low germination is a potential risk. Planting population should be adjusted accordingly due to lack of germination and vigor if PSS is present. This research help growers for purple seed management, and scientists to further understand the potential negative impact on seed quality and nutrition. Further research is needed before conclusive recommendations are made. Full article

Research on biologically active compounds has been increased in order to improve plant protection against various environmental stresses. Among natural sources, plants are the fundamental material for studying these bioactive compounds as their immune system consists of many peptides, proteins, and hormones. Osmotin is a multifunctional stress-responsive protein belonging to pathogenesis-related 5 (PR-5) defense-related protein family, which is involved in inducing osmo-tolerance in plants. In this scenario, the accumulation of osmotin initiates abiotic and biotic signal transductions. These proteins work as antifungal agents against a broad range of fungal species by increasing plasma membrane permeability and dissipating the membrane potential of infecting fungi. Therefore, overexpression of tobacco osmotin protein in transgenic plants protects them from different stresses by reducing reactive oxygen species (ROS) production, limiting lipid peroxidation, initiating programmed cell death (PCD), and increasing proline content and scavenging enzyme activity. Other than osmotin, its homologous proteins, osmotin-like proteins (OLPs), also have dual function in plant defense against osmotic stress and have strong antifungal activity. Full article

Global warming and changes in rainfall patterns may put many ecosystems at risk of drought. These stressors could be particularly destructive in arid systems where species are already water-limited. Understanding plant responses in terms of photosynthesis and growth to drought and rewatering is essential for predicting ecosystem-level responses to climate change. Different drought responses of C3 and C4 species could have important ecological implications affecting interspecific competition and distribution of plant communities in the future. For this study, C₄ plant Pennisetum centrasiaticum and C₃ plant Calamagrostis pseudophragmites were subjected to progressive drought and subsequent rewatering in order to better understand their differential responses to regional climate changes. We tracked responses in gas exchange, chlorophyll fluorescence, biomass as well as soil water status in order to investigate the ecophysiological responses of these two plant functional types. Similar patterns of photosynthetic regulations were observed during drought and rewatering for both psammophytes. They experienced stomatal restriction and nonstomatal restriction successively during drought. Photosynthetic performance recovered to the levels in well-watered plants after rewatering for 6–8 days. The C4 plant, P. centrasiaticum, exhibited the classic CO₂-concentrating mechanism and more efficient thermal dissipation in the leaves, which confers more efficient CO₂ assimilation and water use efficiency, alleviating drought stress, maintaining their photosynthetic advantage until water deficits became severe and quicker recovery after rewatering. In addition, P. centrasiaticum can allocate a greater proportion of root biomass in case of adequate water supply and a greater proportion of above-ground biomass in case of drought stress. This physiological adaptability and morphological adjustment underline the capacity of C₄ plant P. centrasiaticum to withstand drought more efficiently and recover upon rewatering more quickly than C. pseudophragmites and dominate in the Horqin Sandy Land. Full article

Convergence is commonly caused by environmental filtering, severe climatic conditions and local disturbance. The basic aim of the present study was to understand the pattern of leaf traits across diverse desert plant species in a common garden, in addition to determining the effect of plant life forms (PLF), such as herb, shrub and subshrub, phylogeny and soil properties on leaf traits. Six leaf traits, namely carbon (C), nitrogen (N), phosphorus (P), potassium (K), δ¹³C and leaf water potential (LWP) of 37 dominant desert plant species were investigated and analyzed. The C, N, K and δ¹³C concentrations in leaves of shrubs were found higher than herbs and subshrubs; however, P and LWP levels were higher in the leaves of subshrubs following herbs and shrubs. Moreover, leaf C showed a significant positive correlation with N and a negative correlation with δ¹³C. Leaf N exhibited a positive correlation with P. The relationship between soil and plant macro-elements was found generally insignificant but soil C and N exhibited a significant positive correlation with leaf P. Taxonomy showed a stronger effect on leaf C, N, P and δ¹³C than soil properties, explaining >50% of the total variability. C₃ plants showed higher leaf C, N, P, K and LWP concentration than C₄ plants, whereas C₄ plants had higher δ¹³C than C₃ plants. Legumes exhibited higher leaf C, N, K and LWP than nonlegumes, while nonlegumes had higher P and δ¹³C concentration than legumes. In all the species, significant phylogenetic signals (PS) were detected for C and N and nonsignificant PS for the rest of the leaf traits. In addition, these phylogenetic signals were found lower (K-value < 1), and the maximum K-value was noted for C (K = 0.35). The plants of common garden evolved and adapted themselves for their survival in the arid environment and showed convergent variations in their leaf traits. However, these variations were not phylogenetics-specific. Furthermore, marks of convergence found in leaf traits of the study area were most likely due to the environmental factors. Full article

The historical cultivation of common bean (Phaseolus vulgaris L.) has resulted in the development of local populations/cultivars in restricted Italian rural areas. Many common bean landraces, still cultivated in small mountain areas from Sicily, have become outdated and endangered due to the commercial varieties spreading. These accessions are poorly known but often represent a genetic heritage to be preserved and enhanced. The ex situ conservation of fifty-seven Sicilian common bean landraces was carried out at the “Living Plants Germplasm Bank” at Ucria (Messina, Italy), founded by the Nebrodi Regional Park, together with the “Sicilian Plant Germplasm Repository” of University of Palermo (SPGR/PA). To assess the germplasm genetic diversity, nineteen morphological traits and eight Simple Sequence Repeats (SSRs) were used. Genetic distances among landraces were calculated to construct a clustering tree by using unweighted pair group method arithmetic (UPGMA). Seed germplasm diversity of Sicilian common bean varied from 80.7% to 93.3%, based on six seed descriptors and six leaf, flower, and pod descriptors, respectively, while cluster genetic analysis depicted a clear separation among all the 57 landraces. Principal coordinates (PCoA) and STRUCTURE analyses showed a prevalent rate of admixture between Mesoamerican and Andean gene pools in Sicilian common bean collection, confirming its heterogeneity. The observed high level of diversity evidenced the needs to adopt accurate criterion to plan a definitive ex situ germplasm collection to share agrobiodiversity with local farmers and to avoid any further loss of genetic resources in rural and protected areas. Full article

This study analyzed the antimicrobial, cytotoxic, and antioxidant properties of Cnidiumofficinale (CO) extracts to confirm their antimicrobial activity toward oral microorganisms. The control group contained 0 μg/mL of CO, and the experimental groups contained 50, 100, 150, and 200 μg/mL of CO. To confirm the antibacterial activity of CO extracts against microorganisms in the oral cavity, an inhibition zone test, a colony-forming unit (CFU) analysis, an optical density (OD) evaluation, and a SEM (scanning electron microscopy) analysis were performed. A cytotoxicity test was also conducted to determine cell viability, and the contents of flavonoids and polyphenols were measured to analyze the extract components. In the control group, the growth inhibition zone increased, while the CFU and OD values decreased (p < 0.05). The SEM analysis confirmed that the number of microorganisms for both the microbes decreased. The cell viability was more than 80% in both the control and experimental groups, excluding the 200 μg/mL sample. The flavonoid and polyphenol contents in the experimental groups showed higher values than those of the control group. Therefore, the CO extract showed considerable antimicrobial activity toward both Streptococcus mutans and Candida albicans, suggesting that it may be used as a natural antimicrobial agent for dental applications. Full article