Camellia Japonica Research Articles

Transcriptome Profiling of Two Camellia japonica Cultivars with Different Heat Tolerance Reveals Heat Stress Response Mechanisms.

Camellia (Camellia japonica) is a semi-shaded plant that is highly vulnerable to heat stress. To investigate the mechanisms underlying heat stress in C. japonica, two C. japonica cultivars, "Xiaotaohong" and "Zhuapolian", which exhibit significant differences in heat tolerance, were selected from four common cultivars. The selection methods included phenotypic observations and physiological index detection, including relative electric conductivity (REC), malondialdehyde (MDA) content, superoxide dismutase (SOD) enzyme activity, relative water content (RWC), and chlorophyll content. RNA-seq analysis yielded 980 million reads and identified 68,455 differentially expressed genes (DEGs) in the two C. japonica cultivars during heat stress compared to the control samples. Totals of 12,565 and 16,046 DEGs were differentially expressed at 16 h and 32 h, respectively, in "Xiaotaohong" during heat stress. In "Zhuapolian", 40,280 and 37,539 DEGs were found at 16 h and 32 h, respectively. KEGG enrichment analysis revealed that both cultivars were enriched in the "plant hormone signal transduction" and "circadian rhythm" pathways at two stages, indicating the critical role these pathways play in the heat stress response. The differences in the tolerance between the two cultivars are likely linked to pathways such as "plant hormone signal transduction", "photosynthesis", and "circadian rhythm". Some members of heat shock proteins (HSPs) are associated with the heat stress response. It is speculated that transcription factor families contributing to the tolerance differences include AP2/ERF, C3H, bHLH, bZIP, and MYB-related with a small number of heat shock factors (HSFs) also induced by the stress. In conclusion, these results reveal the changes in the physiological indices and molecular networks of two C. japonica cultivars under heat stress. This study lays the foundation for the breeding of superior heat-resistant C. japonica cultivars and for further molecular research.

A Review of Medicinal Plants and Phytochemicals for the Management of Gout.

Gout, characterized by elevated uric acid levels, is a common inflammatory joint disease associated with pain, joint swelling, and bone erosion. Existing treatments for gout often result in undesirable side effects, highlighting the need for new, safe, and cost-effective anti-gout drugs. Natural products, including medicinal plants and phytochemicals, have gained attention as potential sources of anti-gout compounds. In this review, we examined articles from 2000 to 2020 using PubMed and Google Scholar, focusing on the effectiveness of medicinal plants and phyto-chemicals in managing gout. Our findings identified 14 plants and nine phytochemicals with anti-gout properties. Notably, Teucrium polium, Prunus avium, Smilax riparia, Rhus coriaria, Foenic-ulum vulgare, Allium cepa, Camellia japonica, and Helianthus annuus exhibited the highest xa-thine oxidase inhibitory activity, attributed to their unique natural bioactive compounds such as phenolics, tannins, coumarins, terpenoids, and alkaloids. Herbal plants and their phytochemicals have demonstrated promising effects in reducing serum urate and inhibiting xanthine. This review aims to report recent studies on plants/phytochemicals derived from herbs beneficial in gout and their different mechanisms.

First Report of Neofusicoccum parvum causing leaf spot on Camellia japonica in China.

Camellia japonica is an important garden landscape plant in southern China. In April 2022, leaf spot symptoms were observed at the camellia garden of Jiaying University (24°32'83″N, 17 116°12'31″E) in Meizhou city, Guangdong Province, China. The initial symptoms were grayish brown spots on the leaves, as the disease progressed, the lesions were enlarged and affected the whole leaf and eventually led to the loss of its ornamental value. The disease incidence was above 15%. Leaf pieces (5 × 5 mm) from 3 diseased Camellia leaves were sterilized in 75% ethanol for 1 min, then in 1% NaOCl for 1 min; and rinsed three times with sterile water. Leaf pieces were inoculated on potato dextrose agar (PDA) medium and incubated at 25 °C. Three days later, fungal colonies initially showed a white aerial mycelium, turning gray after 5 days, and dark gray after 7 days of incubation. Conidia were single-celled, hyaline, ellipsoidal and without septa. Dimensions of conidia (n≥50) were 14.27 to 20.65 × 4.28 to 6.56 μm. The morphological characteristics matched the genus Neofusicoccum (Pavlic et al. 2009). For molecular identification, the rDNA internal transcribed spacer (ITS1, 5.8S and ITS2) region, translation elongation factor 1-alpha (tef1-α), and beta-tubulin (tub2) of a representative isolate SC6-2 were amplified using the primer pairs ITS1/ITS4, EF1/EF2 and BT2a/-BT2b, respectively (Golzar and Burgess，2011). The sequences obtained were deposited in GenBank (accession nos. PP064173, PP479650 and PP082457 for ITS, tef1-α and tub2, respectively). Nucleotide BLAST analysis showed a 99.81% homology with N. parvum (519/520 bp, OQ509869; 519/520 bp, KF294003; 518/519 bp KF293989) for ITS, 100% homology with N. parvum (398/398 bp, MN318108; 398/398 bp, MK294085; 398/398 bp, MH936021) for tub2, and >99% homology with N. parvum (259/259 bp, 100%, MW390561; 263/265 bp, 99.25%，MN175952; 263/265 bp, 99.25%, MK781982) for tef1-α. The combined phylogenetic analyses (ITS, tef1-α, and tub2) showed that the sequence of the tested isolate and the corresponding sequence of N. parvum (CMW9081, SHSJ1-2) in GenBank grouped in the same branch of the phylogenetic tree. Based on morphological characters, DNA sequencing, and the phylogenetic tree, it can be determined that the pathogen was Neofusicoccum parvum. Inoculation on Camellia leaves was performed to confirm pathogenicity. Nine healthy camellia leaves were pin-pricked with a sterile needle and inoculated with mycelial plugs of isolate SC6-2. Nine other healthy leaves were pin-pricked and inoculated with noncolonized PDA plugs as control leaves. The inoculated leaves were maintained on water agar solid medium at 25°C. To keep a high-humidity environment the inoculation sites were covered by moistened cotton for 2 days. The experiment was repeated three times. Five days after inoculation, all the inoculated leaves showed similar symptoms to those observed in the field, whereas control leaves were asymptomatic for 6 days. The fungal isolates recovered from inoculated leaves were morphologically identical to the N. parvum isolates originally recovered from symptomatic leaves collected in the field, fulfilling Koch's postulates. Neofusicoccum parvum is an aggressive pathogen that causes severe disease on important tree and woody species (Liddle et al. 2019). It has been reported that N. parvum can infect the leaves and branches of grapes (Otoya-Martinez et al. 2023), dieback on Camellia japonica (Pintos, et al. 2012), Brazilian pepperwood (Bertetti et al. 2022), mango (Giancarlo et al. 2023) and other plants. To our knowledge, this is the first report of N. parvum causing leaf spot on Camellia japonica in China.

Flavor Chemical Research on Different Bee Pollen Varieties Using Fast E-Nose and E-Tongue Technology.

Bee pollen, derived from various plant sources, is renowned for its nutritional and bioactive properties, aroma, and taste. This study examined the bee pollen with the highest yield in China obtained from four plant species, namely Brassica campestris (Bc), Nelumbo nucifera (Nn), Camellia japonica (Cj), and Fagopyrum esculentum (Fe), using fast e-nose and e-tongue technology to analyze their flavor chemistry. Results showed substantial differences in scent profiles among the varieties, with distinct odor compounds identified for each, including n-butanol, decanal, and ethanol, in Bc, Nn, and Cj, respectively. The primary odorants in Fe consist of E-2-hexen-1-ol and (Z)-3-hexen-1-ol. Additionally, e-tongue analysis revealed seven distinct tastes in bee pollen samples: AHS, PKS, CTS, NMS, CPS, ANS, and SCS, with variations in intensity across each taste. The study also found correlations between taste components and specific odor compounds, providing insights for enhancing product quality control in bee pollen processing.

First Report of Leaf Blight of Camellia japonica Caused by Diaporthe fukushii in Tennessee and the United States.

Japanese camellia (Camellia japonica), is an important ornamental species that has an increasing economic value in China, Japan, Australia and the USA (Vela et al. 2013). Leaf blight symptoms were observed on 20-year-old C. japonica 'April Tryst' leaves collected from a research plot in McMinnville, TN in March 2022. Leaf blight first appeared in the leaf tips and was irregular in shape (2 to 3 cm in diameter). Affected areas displayed gray color discoloration with a deep black margin and gradually expanded in size along the leaf margin, eventually causing leaf death and defoliation. Dark brown globose to subglobose conidiomata (pycnidia) were observed abundantly on the infected leaves (Fig. 1a). Disease severity was 25 to 50% of leaf area and incidence was 10% out of 60 plants. Three leaves were collected from each symptomatic plant and the surface disinfected with 10% NaOCl for 60 s, washed thrice with distilled water, and plated on potato dextrose agar (PDA). Colony growth of the isolates FBG4744 and FBG6184 on PDA, 15 days after incubation at 25°C (light/dark: 12/12h) were white to pale grey with dense and felted mycelium with concentric zonation. Spherical black pycnidia were observed on the concentric rings 2-3 weeks after incubation. Alpha conidia were on average 7.15 × 4.82 µm (4.89 to 9.37 µm × 2.91 to 6.74 µm) in size and were aseptate, hyaline, smooth, and ellipsoidal (n=50). Beta conidia were not observed. Pathogen identity was confirmed by extracting total DNA using the DNeasy PowerLyzer Microbial Kit from 7-day-old cultures. Primer pairs ITS1/ITS4 (White et al. 1990), T1/T222 and EF1/EF2 (Stefańczyk et al. 2016) were used to amplify and sequence the ribosomal internal transcribed spacer (ITS), beta-tubulin (BT), and translation elongation factors 1-α (EF1-α) genetic markers, respectively. The sequences (GenBank accession nos. OR607729, ITS; OR608485, BT; OR608487, EF1-α) were 100% similar to Diaporthe fukushii (=Phomopsis fukushii) in the NCBI nr/nt database (JQ807450: ITS; MG812590: BT, and MG281573: EF1-α). A phylogenetic analysis was performed using concatenated sequences of ITS, BT, and EF1-α of D. fukushii and other closely related taxa retrieved from GenBank (Fig. 2). Pathogenicity tests were performed on 1-year-old 10 healthy potted plants of C. japonica 'April Tryst' per isolate (Mathew et al. 2015; Yang et al. 2019). One leaf per plant was wounded with a sterilized 0.2-mm needle. PDA plugs (5 mm) taken from 7-day old cultures of FBG4744 and FBG6184 isolates were deposited on the wounded leaves and covered with moist cotton (Yang et al. 2019; Zhao et al. 2020). Ten additional plants were used as control and sterile PDA plugs were placed on the wounded leaves. Plants were covered with clear plastic bags and kept inside a greenhouse at 21 to 23°C, 70% RH, 16 h photoperiod. All inoculated leaves exhibited blight symptoms 14 days after inoculation (Fig. 1b) while control plants remained asymptomatic (Fig. 1c). The pathogen was reisolated from all the inoculated leaves and was confirmed as D. fukushii using morphological and molecular tools. Diaporthe species (D. tulliensis, D. passiflorae and D. perseae) have been previously reported to cause leaf spot on Camellia sinensis in Taiwan (Ariyawansa et al. 2021), but to our knowledge, this is the first report of leaf blight of C. japonica caused by Diaporthe fukushii in Tennessee and the United States. Identification of this novel disease is important in developing necessary management approaches.

Enrichment process, structural prediction, isolation, in vitro cytotoxic and anti-inflammatory effects of triterpenoid saponins in Camellia japonica L. leaves water extract through UPLC-Q-TOF based mass spectrometry similarity networking

Camellia japonica L. is rich in bioactive compounds, but its health-enhancing potential is often overshadowed by its ornamental value. Notably, triterpenoid saponins are prominent due to their surfactant properties. MolNetEnhancer revealed 537 compounds in C. japonica leaves water extract, classified into 32 categories, including 38 triterpenoid saponins. To enrich triterpenoid saponins, the process of D101 resin chromatography was employed. Molecular networking analysis based on UPLC-Q-TOF and quantitative analysis based on HPLC revealed saponins concentrated in fractions 3 and 4 (68.3% transfer). MS2LDA and NAP predicted structures for 38 triterpenoid saponins, revealing nearly half of them are potential new compounds. Comprehensive chromatographic and spectroscopic methods were used for purification and structural illustration of triterpenoid saponins, yielding 13, including 7 new compounds. Statistical analysis and in vitro assays revealed the cytotoxic and anti-inflammatory activities of these triterpenoid saponins played a crucial role in the anticancer effects.

Anti-oxidant activities of ethanol extract and fractions from defatted Camellia japonica L. seeds

Anti-oxidant activities of ethanol extract and fractions from defatted <i>Camellia japonica</i> L. seeds

Pest categorisation of Pochazia shantungensis.

The EFSA Panel on Plant Health performed a pest categorisation of Pochazia shantungensis (Hemiptera: Auchenorrhyncha: Ricaniidae) for the EU following commodity risk assessments of Malus domestica, Prunus persica, P. dulcis and Robinia pseudoacacia plants for planting from Türkiye in which P. shantungensis was identified as a pest that could potentially enter the EU. The native range of P.shantungensis is China (Shaanxi, Shandong and Zhejiang provinces), but around 2010, the species entered the Republic of Korea and rapidly spread. Small and localised populations were also recently found in Türkiye (Marmara) and southern Russia (Krasnodyarskiy kray). Within the EU, a few individuals have been recorded in Italy (Pistoia province, Tuscany), in one locality in southern France (Alpes-Maritimes), in the Netherlands (Western Netherlands) and in one garden in Germany (Baden-Württemberg) where it was eradicated. P. shantungensis is not listed in Annex II of Commission Implementing Regulation (EU) 2019/2072. It is polyphagous, feeding on plants belonging to more than 200 species including many crop and ornamental plants. Economically important hosts in the EU include apple (M. domestica), citrus (Citrus spp.), walnut (Castanea sp.) and ornamentals such as hibiscus (Hibiscus spp.) and camellia (Camellia japonica), as well as forest trees, mostly deciduous. In the Republic of Korea, the species has one generation per year. It overwinters as eggs and goes through five nymphal instars. Its impact is due to oviposition obstructing the vascular system of its hosts, depletion of the host resources and egestion of honeydew promoting the development of sooty moulds. Plants for planting constitute the main pathway for entry into the EU and for spread. Climatic conditions in southern EU countries and host plant availability in those areas would allow establishment and spread. The introduction of P. shantungensis is expected to have an economic impact in the EU through the reduction in yield, quality and commercial value of fruits and ornamental plants. Phytosanitary measures are available to reduce the likelihood of entry and further spread. P.shantungensis meets the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Untargeted metabolomics and in vitro functional analysis unravel the intraspecific bioactive potential of flowers from underexplored Camellia japonica cultivars facing their industrial application

The Camellia genus comprises a vast array of underexplored medicinal plants that merit a systematic valorization to exploit their potential as natural sources of phytochemicals with associated health-promoting properties. In this work, flower extracts from eight poorly characterized Camellia japonica L. cultivars were subjected to polyphenol profiling through untargeted metabolomics combined with in vitro functional analysis. Anthocyanins, mostly represented by cyanidin 3-O-glycosides, flavones, and flavonols, were found as the major constituents of C. japonica flowers, together with hydroxycinnamic acids, tyrosols, alkylphenols, and stilbenes, which were detected for the first time in this species. The application of multivariate statistics revealed a flower color-dependent fingerprint of C. japonica cultivars, featuring anthocyanins and other flavonoids as metabolite markers associated with color-flowered cultivars with respect to white-flowered ones. The accumulation of anthocyanins, especially reported in ‘Eugenia de Montijo’ flowers, was highly correlated with the cytotoxic and anti-inflammatory properties of the derived extracts, including AGS, Caco-2, and MCF7 cancer cell lines. Moreover, the flavones accumulation reported in ‘Carolyn Tuttle’ extracts was also associated with high rates of free-radical scavenging activity, as well as a potent cytotoxicity against the Caco-2 cell line. In general, C. japonica anthocyanin-enriched flower extracts were revealed as promising candidates for the industrial production of polyphenols with associated biological activities of high interest for critical sectors in the food, pharmaceutical, and cosmetic industries.

Preference of Helopsaltes pleskei (Taczanowski, 1890) (Aves: Passeriformes: Locustellidae) on uninhabited islets (Chengdo, Jikgudo, and Heukgeomdo) in South Korea as breeding sites

This study was conducted to investigate the habitat and breeding status of the Pleske's Grasshopper Warbler (Locustella pleskei) inhabiting unmanned coastal islets (Cheongdo, Jikgudo and Heukgeomdo) on the Jeju Chuja Marine Provincial Park in South Korea. A total of 13 nesting sites were observed between April 2019 and April 2021. Six Camellia japonica (4 ea), Pinus thunbergii (1 ea) and Eurya emarginata (1 ea) nesting sites were found in the Cheongdo islet. Four C. japonica (2 ea), P. thunbergii (1 ea) and Elaeagnus macrophylla (1 ea) tree sites in Jikgudo islet were found, whereas only three C. japonica sites on the Heukgeomdo islet were observed. During the study period, 36 individuals were observed: 14 in Cheongdo, 10 in Jikgudo and 12 in the Heukgeomdo Islets. Most nesting sites were located in the bushy areas of the inner islets. Thus, birds tended to select nesting locations in response to predation and microclimates to increase reproductive rates and maximize offspring survival. This study highlights the importance of unmanned islands (islets) and the presence of bushy shrubs as important nesting and hiding sites for the ecologically vulnerable Pleske's Grasshopper Warbler.

Terra Nostra Garden 2023 dataset of Camellia species, hybrids and their cultivars (Azores, Portugal).

Camellias cultivars collections, comprising an exquisite array of meticulously bred and curated camellia varieties, emerged as indispensable elements within the resplendent 19th century gardens that adorned landscapes across the globe. The heart of Terra Nostra Garden, nestled within the captivating surroundings of the Furnas volcano on S. Miguel Island (Azores, Portugal), started in the year 1782 as an enchanting fishpond garden, strategically positioned in front of the summer house belonging to the esteemed Thomas Hickling, the American vice-consul. Soon this garden was enlarged and embellished with species from several continents. This tradition continued during all the 19th century with the Viscount Duarte Borges da Câmara Medeiros (1848-1872) and his son the Marquis António Borges Medeiros Dias da Câmara e Sousa (1872-1913). In 1933, the 12 hectares property was acquired by the Terra Nostra Society, led by Vasco Bensaude and increased to 12.5 hectares. In 1935, the current Terra Nostra Garden Hotel was inaugurated and, two years later, the Terra Nostra Society reopened the botanical garden attached to the hotel, now called Terra Nostra Garden. Beginning in 1982, the Head Gardener embarked on a transformative journey, dedicating his expertise to the meticulous renovation and expansion of numerous botanical collections nestled within the garden's enchanting landscapes. Amongst the remarkable transformations, the revered camellias collection received special attention, as it underwent a comprehensive rejuvenation process under his skilful guidance. The recent publication of a global digital dataset of Camellia names provides the opportunity to publish the dataset of Camellia species, hybrids and its cultivars currently cultivated at Terra Nostra Garden with their validated names. In June 2023, a total of 669 Camellia phenotypes were identified across the 12.5 hectares of Terra Nostra Garden. These phenotypes include 38 species, 178 hybrids and 637 cultivars. Camelliajaponica represents 81.7% of the 459 species cultivars, while C. x williamsii accounts for 32% of 178 hybrid cultivars. The most prevalent genotypes in Camellia hybrids with known parentage are those of C.japonica, C.saluenensis and C.reticulata present respectively in 64.1%, 45.5% and 37.9% of the hybrids. Regarding cultivar registration, 46.9% were registered in the US, followed by 13% from Japan and 10.8% from Portugal. Although the most ancient cultivar registered growing at the garden is Camelliareticulata Lindl. 'Damanao' from 1621, the majority (69.4%) of cultivars in the garden were registered in the 20th century, followed by the 19th century cultivars (20.7%). One cultivar, Camellia 'Patrícia Bensaude Fernandes', was produced and registered specifically by this garden.

Occurrence of fatty acids in Camellia genus: Extractions technologies and potential applications: A review

The Camellia genus (Theaceae) comprises more than 200 species, including the most famous Camellia sinensis (L.) Kuntze, Camellia oleifera Abel, and Camellia japonica (L.). The commercial interest in these plants linked to their seed fatty acid content increased in the last decades due to their quality and health-enhancing properties, which significantly depend on different aspects such as environmental conditions. Nowadays, the traditional extraction methods of fatty acids from camellias include mechanical press extraction and solvent extraction, which have a high environmental impact. Therefore, it is essential to develop extraction techniques to achieve the maximum lipid yield with the minimum environmental impact and cost. These innovative methods include enzymatic extraction, supercritical fluid extraction (SFE), microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). However, they are often limited to the laboratory or pilot scale due to economic or technical bottlenecks. This article aims to explore recent advances and innovations related to the extraction of fatty acids from Camellia.

New biofunctional effects of oleanane-type triterpene saponins.

In the current review, we describe the novel biofunctional effects of oleanane-type triterpene saponins, including elatosides, momordins, senegasaponins, camelliasaponins, and escins, obtained from Aralia elata (bark, root cortex, young shoot), Kochia scoparia (fruit), Polygala senega var. latifolia (roots), Camellia japonica (seeds), and Aesculus hippocastanum (seeds), considering the following biofunctional activities: (1) inhibitory effects on elevated levels of blood alcohol and glucose in alcohol and glucose-loaded rats, respectively, (2) inhibitory effects on gastric emptying in rats and mice, (3) accelerative effects on gastrointestinal transit in mice, and (4) protective effects against gastric mucosal lesions in rats. In addition, we describe (5) suppressive effects of the extract and chakasaponins from Camellia sinensis (flower buds) on obesity based on inhibition of food intake in mice. The active saponins were classified into the following three types: (1) olean-12-en-28-oic acid 3-O-monodesmoside, (2) olean-12-ene 3,28-O-acylated bisdesmoside, and (3) acylated polyhydroxyolean-12-ene 3-O-monodesmoside. Furthermore, common modes of action, such as involvements of capsaicin-sensitive nerves, endogenous NO and PGs, and possibly sympathetic nerves, as well as common structural requirements, were observed. Based on our findings, a common mechanism of action might mediate the pharmacological effects of active saponins. It should be noted that the gastrointestinal tract is an important action site of saponins, and the role of the saponins in the gastrointestinal tract should be carefully considered.

Ecological Characteristics of Evergreen Forest in Yesong-ri, Wando-gun (Natural Monument No. 40)

Background and objective: Evergreen broad-leaved forests native to the islands of the southwest coast have been adapted to a range of climatic or geographical environmental factors. Although they are of high importance as cultural and ecological landscape resources, they have been damaged by tourism and climate change, and thus measures to protect and manage them are required. This study was conducted to suggest the characteristics of the vegetation structure and management plan of the evergreen forest in Yesong-ri, Natural Monument No. 40.Methods: Twenty-three quadrats were established in the vegetation communities where broad-leaved evergreens dominate or appear in the canopy, understory, and shrub layers, and the area where the vegetation was restored after the buildings was demolished. Based on survey data on the vegetation, the characteristics were identified after classifying the communities using TWINSPAN and DCA ordination techniques.Results: The plant communities were classified into a total of 5 dominant groups: &lt;i&gt;Castanopsis sieboldii-Camellia japonica, C. sieboldii, Celtis sinensis, Neolitsea sericea, Camellia japonica&lt;/i&gt;, and &lt;i&gt;Machilus thunbergii-Quercus glauca&lt;/i&gt;. The study site was a windbreak forest that has been protected and managed by the villagers for a long time. As time passes, broad-leaved evergreens including &lt;i&gt;N. sericea, Q. acuta&lt;/i&gt;, and &lt;i&gt;C. sieboldii&lt;/i&gt; have flowed into and spread to the surrounding area. It seems that a similar but unique ecosystem was formed. Looking into the relationship between environmental factors and vegetation distribution, it was analyzed that the slope, clay, and Na&lt;sup&gt;+&lt;/sup&gt; had direct or indirect effects on the vegetation distribution.Conclusion: The width of the windbreak forest was narrow, and the continuity was interrupted by the indiscriminate activities of tourists, installation of facilities, expansion and construction of warehouses and commercial facilities, and the destruction of peripheral and understory vegetation was in progress. To maintain the integrity of the forest, it is necessary to purchase and demolish buildings and facilities belonging to the interior after establishing boundaries and spheres of influence, and to restore it to a good evergreen broad-leaved forest using a reference model for areas with damaged vegetation and manage it.

Morphology, Phylogeny, and Pathogenicity of Colletotrichum Species Causing Anthracnose in Camellia japonica in China

Camellia japonica is a renowned flower and an influential plant in Chinese urban landscaping. However, Colletotrichum, one of the world’s most commercially important phytopathogenic genera that causes anthracnose on a wide range of plant species, have annually caused significant economic losses to Ca. japonica. In this study, 115 strains were isolated from Ca. japonica leaves with typical symptoms from the provinces of Hunan, Jiangxi, Hainan, Guangxi, Hubei, Chongqing, Guizhou, and Shanxi. They were then subjected to pathogen identification and using method of morphology combined with ApMat gene sequence analysis, along with the pathogenicity tests based on Koch’s postulates. The 115 strains were identified as C. gloeosporioides, C. fructicola, C. siamense, C. camelliae or C. aeschynomenes. Pathogenicity tests revealed that all species produced brown lesions on healthy Ca. japonica leaves, indicating significant virulence. Furthermore, C. fructicola had the broadest distribution and the highest isolation rate., Most importantly, this is the first report in China of C. aeschynomenes causing the anthracnose disease in Ca. japonica.

Gray Blight Disease on Euonymus japonicas Caused by Pestalotiopsis disseminata in China.

Euonymus japonicas is widely planted as an important landscape species throughout China. In June 2021, a serious gray blight disease was detected on E. japonicas in Henan Province (32°30'58" N, 112°19'44" E), causing severe defoliation of infected trees with a foliar disease incidence of 52 to 70% (n = 100). Gray spots initially appeared on leaves, gradually expanded into irregular white blotches with dark brown borders, eventually leading to wilting and death of the leaves. The junctions between the lesion and healthy tissue of infected leaves were cut into 3 × 3-mm pieces, surface sterilized with 1% NaClO solution for 1 min, rinsed in sterile water, and placed on PDA plates with 50 μg/ml of streptomycin. Three isolates (HY94, HY95, and HY98) were selected for subsequent experiments. The colonies reached 80-85 mm diam after 7 days at 25°C, with undulated margins, white to pale in color, with moderate aerial mycelium on the surface. Conidiomata were globose, solitary, and dark black. Conidia were ellipsoid, straight to slightly curved, 4-septate, 19 to 26.4 × 5 to 7.5 μm (n=100). The apical cell was cylindrical and hyaline, with 2 to 3 tubular apical appendages, unbranched, filiform, 2.5 to 3.5 μm in length. The basal appendage was single, unbranched, centric, 1.5 to 3 μm long. The characteristics were close to those of Pestalotiopsis spp. (Maharachchikumbura et al. 2013). The genomic DNA was extracted, and the rDNA internal transcribed spacer (ITS), the β-tubulin gene (TUB), and the translation elongation factor 1-alpha gene (TEF1) were amplified by primers ITS1/ITS4, Bt2a/Bt2b, and EF1-728F/EF1-986R, respectively (Carbone and Kohn, 1999). Sequences were submitted to GenBank with accession numbers OL840327-OL840329(ITS), OL961454-OL961456(TUB), and OL961448-OL961450 (TEF1). BLASTn analyses of ITS, TUB, and TEF1 sequences exhibited 99.46, 99.05, and 96.53% similarity to the sequences of Pestalotiopsis disseminata strain MEAN1166 (ITS, 548/551 bp; MT374688) (Silva et al. 2020), PSH2000I-066 (TUB, 418/422 bp; DQ333575), and TAP29O082 (TEF1, 250/259 bp; AB453850), respectively in GenBank. The three isolates formed a clade with the type strains, MEAN 1166 and MAFF238347 of P. disseminata in phylogenetic trees, being clearly seperated from other Pestalotiopsis spp. Based on morphological and molecular evidence, the pathogen was identified as P. disseminata (Maharachchikumbura et al. 2011). To fulfill Koch's postulates, pathogenicity was tested with three isolates. Ten healthy leaves of 5-year-old intact plants were used per isolate and inoculated with mycelial plugs on both nonwounded and wounded leaves. Control leaves were inoculated with agar plugs. The inoculated plants were placed at 28°C in a greenhouse (90% relative humidity). Distinct lesions were observed after 10 days. The pathogen reisolated was identical to that of the original cultures according to phenotype and ITS sequences. The control leaves showed no obvious symptoms. P. disseminata is known to cause disease on several important plants in China, such as Camellia japonica (Zhang et al. 2012), Pinus armandii (Hu et al. 2007), and Tripterygium wilfordii (Kumar et al. 2004). This is the first report of gray blight disease caused by P. disseminata on E. japonicas in China and worldwide. The fungal pathogen identification will provide valuable information for prevention and management of gray blight disease associated with E. japonicas.

Assessment of the anti-hair loss potential of Camellia japonica fruit shell extract in vitro.

Hair loss is caused by various factors. Impacts of these factors are often overlapped and intensified. Currently, mitigation of hair loss is being studied by proliferating dermal papilla cells (DPCs) and inhibiting deleterious factors such as dihydrotestosterone (DHT) and oxidative stress on hair growth. Camellia japonica (C.japonica) fruit shell is a discarded part. Its biological activity remains to be elucidated. In this study, we investigated the capacity of C.japonica fruit shell extract (CJFSE) for hair loss mitigation. MTT assay, spheroid culture and quantitative RT-PCR were performed to observe the proliferative effect of CJFSE on hair follicle dermal papilla cells (HFDPCs). Effects of CJFSE on DHT-induced hair loss were confirmed by Dkk-1 ELISA, β-galactosidase (β-gal) and 5α-reductase activity assay. In addition, effects of CJFSE on oxidative stress were confirmed through DPPH and ROS production assays. CJFSE increased the proliferation and spheroid size of HFDPCs. Expression levels of VEGF-A, Wnt-1, c-Myc and Cyclin D1 were upregulated by CJFSE. CJFSE also suppressed 5α-reductase activity and DHT-induced decrease in cell proliferation, Dkk-1 secretion and β-gal activity. Moreover, CJFSE showed DPPH scavenging activity and ameliorated hydrogen peroxide-induced ROS production and β-gal activity. Finally, gallic acid and protocatechuic acid were observed in CJFSE through HPLC analysis. CJFSE has the potential to alleviate hair loss by promoting hair cell growth and suppressing effects of DHT and oxidative stress on hair.

Transcriptome Analysis Reveals the Molecular Mechanisms Associated with Flower Color Formation in Camellia japonica ‘Joy Kendrick’

Camellia japonica is a woody flower with high ornamental and economic value used for landscaping and as a pot plant. Floral colors are among the most important ornamental traits of flower plants, particularly multicolored flowers. The C. japonica cultivar ‘Joy Kendrick’ has multicolored flowers; the corolla is pink with darker red stripes, but the molecular mechanism underlying this trait is unknown. Here, pigment analysis showed that there are more anthocyanins accumulate in red petal regions than in pink areas, which may be key to formation of red stripes. Furthermore, transcriptome analysis revealed that anthocyanin biosynthesis, modification, and transporter genes are highly expressed in red stripes, consistent with the observed anthocyanin accumulation. In addition, many plant hormone signal transduction genes, particularly auxin, may contribute to the regulation of red stripe formation. This study provides broad insights into pigment accumulation and the regulatory mechanisms underlying floral color formation in C. japonica, and lays a foundation for breeding new C. japonica varieties.

Visual preference of plant features in different living environments using eye tracking and EEG.

Plants play a very important role in landscape construction. In order to explore whether different living environment will affect people's preference for the structural features of plant organs, this study examined 26 villagers and 33 college students as the participants, and pictures of leaves, flowers and fruits of plants as the stimulus to conduct eye-tracking and EEG detection experiments. We found that eye movement indicators can explain people's visual preferences, but they are unable to find differences in preferences between groups. EEG indicators can make up for this deficiency, which further reveals the difference in psychological and physiological responses between the two groups when viewing stimuli. The final results show that the villagers and the students liked leaves best, preferring aciculiform and leathery leaves; solitary, purple and capitulum flowers; and medium-sized, spathulate, black and pear fruits. In addition, it was found that the overall attention of the villagers when watching stimuli was far lower than that of the students, but the degree of meditation was higher. With regard to eye movement and EEG, the total duration of fixations is highly positively correlated with the number of fixations, and the average pupil size has a weak negative correlation with attention. On the contrary, the average duration of fixations has a weak positive correlation with meditation. Generally speaking, we believe that Photinia×fraseri, Metasequoia glyptostroboides, Photinia serratifolia, Koelreuteria bipinnata and Cunninghamia lanceolata are superior landscape building plants in rural areas and on campuses; Pinus thunbergii, Myrica rubra, Camellia japonica and other plants with obvious features and bright colours are also the first choice in rural landscapes; and Yulania biondii, Cercis chinensis, Hibiscus mutabilis and other plants with simple structures are the first choice in campus landscapes. This study is of great significance for selecting plants for landscape construction and management according to different environments and local conditions.

Camellia japonica Root Extract Increases Antioxidant Genes by Induction of NRF2 in HeLa Cells.

Camellia japonica L. (Theaceae) has been used for medicinal and cosmetic purposes in East Asian countries. Most functional components were obtained from the upper parts of the tree, such as leaves, flowers, or seeds. Here, we report a functional effect of the 80% methanolic extract of C. japonica root (CJRE) on antioxidative stress in HeLa cells. The nuclear factor erythroid-derived 2-related factor 2 (NRF2) is a key transcription factor that triggers the induction of oxidative stress-relating genes and drug detoxification. As result, CJRE showed a strong anti-radical scavenging effect in a dose-dependent manner. In addition, the induction of antioxidant response elements (ARE)-luciferase activity was maximized at CJRE 200 µg/mL. Furthermore, CJRE induced the mRNA levels of HO-1 and NQO1 by the nuclear NRF2 accumulation. As a possible mechanism of Nrf2 activation, the phosphorylation of p38 and ERK1/2 signaling might fortify the NRF2 induction as well as its stability. However, the phosphorylation of AKT is rather decreased. Taken together, CJRE may potentiate the antioxidant effects by increasing the NRF2 signaling through MAP kinase signaling and the properties of its radical scavenging activity. Thus, CJRE could apply for other medicinal and cosmetic purposes.