Search Results (59)

Seed germination is a critical phase in the plant lifecycle of Camellia oleifera (oil tea), directly influencing seedling establishment and crop reproduction. In this study, we examined transcriptomic and physiological changes across five defined germination stages (G0–G4), from radicle dormancy to cotyledon emergence. Using RNA sequencing (RNA-seq), we assembled 169,652 unigenes and identified differentially expressed genes (DEGs) at each stage compared to G0, increasing from 1708 in G1 to 10,250 in G4. Functional enrichment analysis revealed upregulation of genes associated with cell wall organization, glucan metabolism, and Photosystem II assembly. Key genes involved in cell wall remodeling, including cellulose synthase (CESA), phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), caffeoyl-CoA O-methyltransferase (COMT), and peroxidase (POD) showed progressive activation during germination. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed dynamic regulation of phenylpropanoid and flavonoid biosynthesis, photosynthesis, carbohydrate metabolism, and hormone signaling pathways. Transcription factors such as indole-3-acetic acid (IAA), ABA-responsive element binding factor (ABF), and basic helix–loop–helix (bHLH) were upregulated, suggesting hormone-mediated regulation of dormancy release and seedling development. Physiologically, cytokinin (CTK) and IAA levels peaked in G4, antioxidant enzyme activities were highest in G2, and starch content increased toward later stages. These findings provide new insights into the molecular mechanisms underlying seed germination in C. oleifera and identify candidate genes relevant to rootstock breeding and nursery propagation. Full article

As a unique woody oil crop in China, Camellia oleifera Abel. germplasm resources show significant genetic diversity in Ya’an City. This study measured 60 phenotypic traits (32 quantitative, 28 qualitative) of 302 accessions to analyze phenotypic variation, establish a classification system, and screen high-yield, high-oil germplasms. The phenotypic diversity index for fruit (H’ = 1.36–1.44) was significantly higher than for leaf (H’ = 1.31) and flower (H’ < 1), indicating genetic diversity concentrated in reproductive traits, suggesting potential genetic variability in these traits. Fruit quantitative traits (e.g., single fruit weight CV = 35.37%, fresh seed weight CV = 38.93%) showed high genetic dispersion. Principal component analysis confirmed the fruit factor and economic factor as main phenotypic differentiation drivers. Quantitative traits were classified morphologically, and correlation analysis integrated them into 13 key indicators classified using LSD and range methods. Finally, TOPSIS evaluation selected 10 excellent germplasms like TQ122 and TQ49, with fruit weight, fresh seed yield, and kernel oil content significantly exceeding the population average. This study provides data for C. oleifera DUS test guidelines and proposes a multi-trait breeding strategy, supporting high-yield variety selection and germplasm resource protection. Full article

Camellia oleifera Abel (C. oleifera) is an evergreen shrub classified under the Camellia genus. It is an important oil species and has great economic benefits. At present, C. oleifera is widely cultivated in the Yangtze River Basin in South China, and its wild species are mainly distributed in the native forests of Hainan Province. Therefore, in the current study, we used the MaxEnt model to predict the suitable habitat for C. oleifera and different environmental factors affecting its current and future distribution. The AUC values exceeded 0.98, showing that the simulation of the model was good, and the TSS values were all above 0.96, indicating that the model was feasible. The results showed that C. oleifera was mainly distributed in Southern China, with a total area of 56.68 × 10⁴ km². The suitable habitats of Camellia oleifera are affected by the precipitation of the warmest quarter (bio18), human activity, soil available water content (awc_class), and minimum temperature of the coldest month and seasonal temperature (bio04). Furthermore, rainfall in the warmest quarter (bio18) was recognized as a crucial factor impacting its distribution. Under future climate conditions, the suitable habitat area of C. oleifera is projected to expand with a slight northward shift in its distribution center. Therefore, in addition to maintaining the current planting area of C. oleifera, the planting area can be appropriately expanded upward along the current area and along the Yangtze River Basin. Full article

Background: Camellia oleifera Abel (C. oleifera) is widely cultivated and serves as an important source of edible oil. Yet, during oil production, pruned branches generate significant waste and contribute to environmental pollution. Objectives: In this work, we obtain a natural polysaccharide from the branches of C. oleifera and optimize its extraction using Box–Behnken design (BBD), which is a statistical method commonly used in response surface methodology. Additionally, we study its properties, such as monosaccharide composition, structural features, antioxidant, and anti-inflammatory abilities. Results: BBD was employed to optimize polysaccharide extraction (solid-liquid ratio = 1:40; 90 °C; 130 min) for a higher yield. After purification, the major monosaccharides of branches of C. oleifera’s polysaccharide (CBP) were disclosed as glucose and galactose. Subsequent structural features of CBP were measured. The antioxidant and anti-inflammatory abilities were measured. The highly scavenging rates of the 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radicals, with the chelating capacity of Fe²⁺, indicate potent antioxidant activity of CBP. Conclusions: In general, CBP demonstrated significant anti-inflammatory activity with down-regulating the expression of IL-6 and IL-1β in the LPS-induced macrophage RAW264.7 model. This bioactive polysaccharide adds value to waste branches by offering a novel approach to waste recycling and the development of C. oleifera. Full article

Background: Section Camellia is the most diverse group in the genus Camellia L., and this group of plants has a long history of cultivation in China as popular ornamental flowers and oil plants. Sect. Camellia plants present diverse morphological variations and complexity among species, resulting in uncertainty in the classification of species, which has resulted in a degree of inconvenience and confusion in the use of plant resources and research. Methods: Here, We sequenced and assembled the chloroplast genomes of 6 sect. Camellia and performed comparative chloroplast genome analysis and phylogenetic studies combined with 15 existing sect. Camellia plants. Results: The chloroplast genome of 21 species in sect. Camellia species were quadripartite with length of 156,587–157,068 bp base pairs (bp), and a highly conserved and moderately differentiated chloroplast genome arrangement. The 21 sect. Camellia chloroplast genomes were similar to those of angiosperms, with high consistency in gene number, gene content and gene structure. After the annotation process, we identified a total of 132 genes, specifically 87 sequences coding for proteins (CDS), 37 transfer RNA (tRNA) genes, and 8 ribosomal RNA (rRNA) genes. The ycf1 gene in 21 species of the sect. Camellia was present only in the small single-copy/inverted repeat of a (SSC/IRa) region. Sequence variation was greater in the large single-copy (LSC) region than in the IR region, and the majority of the protein-coding genes presented high codon preferences. The chloroplast genomes of 21 plant species exhibit relatively conserved SC (single copy region)/IR (inverted repeat region) boundaries. We detected a total of 2975 single sequence repeats (SSRs) as well as 833 dispersed nuclear elements (INEs). Among these SSRs, A/T repeats and AT/AT repeats dominated, while among INEs, forward repeats and palindromic repeats predominated. Codon usage frequencies were largely similar, with 30 high-frequency codons detected. Comparative analysis revealed five hotspot regions (rps16, psaJ, rpl33, rps8, and rpl16) and two gene intervals (atpH-atpI and petD-rpoA) in the cp genome, which can be used as potential molecular markers. In addition, the phylogenetic tree constructed from the chloroplast genome revealed that these 21 species and Camellia oleifera aggregated into a single branch, which was further subdivided into two evolutionarily independent sub-branches. Conclusions: It was confirmed that sect. Camellia and C. oleifera Abel are closely related in Camellia genus. These findings will enhance our knowledge of the sect. Camellia of plants, deepen our understanding of their genetic characteristics and phylogenetic pathways, and provide strong support for the scientific development and rational utilization of the plant resources of the sect. Camellia. Full article

Camellia oleifera (Camellia oleifera Abel.) is a key woody oilseed tree. In recent years, China’s Camellia oleifera industry has shifted from extensive to refined management, with an action plan launched to boost productivity and efficiency. This study utilized remote sensing technology to diagnose crop nutrient levels. Focusing on 240 Camellia oleifera trees from four varieties at the Dechang Cooperative in Shucheng County, Anhui Province, the study collected full-spectrum canopy reflectance data (350–2500 nm) across five growing stages: spring shoot, summer shoot, fruit expanding, fruit ripening, and full blooming. First-order derivative (FD) and second-order derivative (SD) transformations were used to preprocess the spectral data and analyze the relationships between leaf potassium concentration (LKC) and the raw spectra (R), FD, and SD. The VCPA-IRIV strategy was then applied to identify sensitive wavelengths and artificial neural network algorithms were used to construct LKC estimation models. The main conclusions are as follows. (1) In the spring shoot stage, LKC ranged from 1.93 to 8.06 g/kg, with an average of 3.70 g/kg; in the summer shoot stage, LKC ranged from 2.01 to 8.82 g/kg, with an average of 4.96 g/kg; in the fruit expanding stage, LKC ranged from 1.40 to 18.27 g/kg, with an average of 4.90 g/kg; in the fruit ripening stage, LKC ranged from 1.45 to 8.90 g/kg, with an average of 3.71 g/kg.; and in the full blooming stage, LKC ranged from 2.38 to 9.57 g/kg, with an average of 5.79 g/kg. Across the five growth stages, the LKC content of Camellia oleifera showed a pattern of initially increasing, then decreasing, and subsequently increasing again. (2) The optimal LKC model for the spring shoot stage was FD-[7,6,2], with ${\mathrm{R}}_{\mathrm{c}}^2$ = 0.6559, RMSEC = 0.1906 in the calibration set, ${\mathrm{R}}_{\mathrm{T}}^2$ = 0.4531, RMSET = 0.2009 in the test set. The optimal LKC model for the summer shoot stage was FD-[6,5,4], with ${\mathrm{R}}_{\mathrm{c}}^2$ = 0.7419, RMSEC = 0.2489 in the calibration set, and ${\mathrm{R}}_{\mathrm{T}}^2$ = 0.7536, RMSET = 0.2259 in the test set; the optimal LKC model for the fruit expanding stage was SD-[7,6,2], with ${\mathrm{R}}_{\mathrm{c}}^2$ = 0.3036, RMSEC = 0.2113 in the calibration set, and ${\mathrm{R}}_{\mathrm{T}}^2$ = 0.3314, RMSET = 0.1800 in the test set; the optimal LKC model for the fruit ripening stage was FD-[10,3,2], with ${\mathrm{R}}_{\mathrm{c}}^2$ = 0.4197, RMSEC = 0.2375 in the calibration set, and ${\mathrm{R}}_{\mathrm{T}}^2$ = 0.5649, RMSET = 0.1772 in the test set, and the optimal LKC model for the full blooming stage was SD-[10,3,2], with ${\mathrm{R}}_{\mathrm{c}}^2$ = 0.7013, RMSEC = 0.2322 in the calibration set, and ${\mathrm{R}}_{\mathrm{T}}^2$ = 0.5621, RMSET = 0.2507 in the test set. Full article

Soil physicochemical properties, root characteristics, and fruit economic traits were determined in Camellia oleifera plantations under spontaneous vegetation + mowing (W1), spontaneous vegetation + glyphosate (W2), and no weeding (CK) treatments. Compared with CK, W1 reduced soil bulk density and increased total nitrogen, total phosphorus, ammonium nitrogen, nitrate nitrogen, and effective potassium content. W2 treatment resulted in higher bulk density than W1 and lower water-holding capacity, total nitrogen, total phosphorus, total potassium, ammonium nitrogen, nitrate nitrogen, and available potassium of the soil. Generally, both W1 and W2 inhibited weed morphological traits while favoring the C. oleifera root system, with the W1 treatment resulting in the greatest increase. Fruit transverse diameter, longitudinal diameter, yield, and oil yield were higher in W1 than in CK and W2 treatments. Weed root systems and C. oleifera root systems ultimately affect oil production and yield by affecting bulk density, ammonium nitrogen, nitrate nitrogen, fruit transverse diameter, seed yield, and seed kernel oil content. In summary, W1 treatment improved the physicochemical properties, root growth, fruit growth, and soil quality in C. oleifera plantations. Full article

Camellia oleifera C. Abel is a woody oil crop with multiple purposes. This study aims to investigate the mutagenic effects of ⁶⁰Co-γ radiation on C. oleifera seedlings and to screen anthracnose-resistant mutants. Two C. oleifera varieties were investigated: ‘Xianglin 1’ (XL1) and ‘Xianglin 210’ (XL210). Seeds were irradiated with 0 Gy, 30 Gy, 50 Gy, and 80 Gy of ⁶⁰Co-γ, and after one year of planting, the mutagenic lines were studied, and disease-resistant mutants were screened. Results showed that as the radiation intensity was increased, the emergence percentage of both C. oleifera XL210 and XL1 was significantly decreased. Radiation significantly changed the SOD and POD activities in both varieties. Furthermore, 80 Gy irradiated lines showed reduced anthracnose resistance in both varieties. However, 50 Gy irradiated lines showed enhanced disease resistance in XL210 while reducing it in XL1. The 30 Gy irradiated lines did not affect the disease resistance of either variety. Colletotrichum gloeosporioides infection tests were conducted on 94 mutant C. oleifera seedlings, resulting in 8 highly resistant mutants (A3, A8, A10, A19, A21, A32, A35, B17) and 3 susceptible mutants (A4, B15, B27) in XL210 and XL1. Differences in SOD and POD activities led to variations in disease resistance among different mutants. Additionally, the expression levels of CoSOD1, CoPOD, CoIDD4, and CoWKRY78 were varied among the different mutants. This study delivers the screening of disease-resistant mutants in C. oleifera through mutagenic breeding, providing material for the development of new C. oleifera varieties and serving as a resource for further research in mutagenic breeding. Full article

Camellia oleifera Abel, one of the most valuable woody oil plants, has been widely cultivated for extracting edible oil. The shell of C. oleifera is a by-product generated in the processing of edible oil extraction. However, there is still limited research on the maturity and high-value resource utilization of shell by-products. We found that the C. oleifera ‘Huashuo’ (HS) fruit shells contained a high content of catechins. Abscisic acid (ABA) and methyl jasmonate (MeJA) enhanced the accumulation of catechins in C. oleifera fruit shells, providing a basis for production and application of the catechins in fruit shells of C. oleifera. We further found that 500 μM ABA and 900 μM MeJA significantly promoted the accumulation of catechin (C) and epicatechin (EC) in fruit shells. Following treatment with 900 μM MeJA, the expressions of CoPAL1, CoC4H1, CoC4H2, CoC4H3, Co4CL1, Co4CL2, CoF3′H1, CoLAR1, CoLAR2, CoLAR3, CoANR2, and CoANRL2 were significantly upregulated, while after 500 μM ABA treatment the expressions of CoPAL3, CoCHS1, CoCHS4, CoF3′H1, CoDFR, CoLAR1, CoLAR2, CoLAR3, CoANS1, CoANR1, and CoANR2 increased dramatically. These results indicate that appropriate concentrations of ABA and MeJA activate C and EC biosynthesis and promote their accumulation in fruit shells. Our results provide new ideas and guidance for promoting the resource utilization of C. oleifera fruit shells. Full article

Drought stress is a critical environmental factor that significantly impacts plant growth and productivity. However, the transcriptome analysis of differentially expressed genes in response to drought stress in Camellia oleifera Abel. is still unclear. This study analyzed the transcriptome sequencing data of C. oleifera under drought treatments. A total of 20,674 differentially expressed genes (DEGs) were identified under drought stress, with the number of DEGs increasing with the duration of drought. Specifically, 11,793 and 18,046 DEGs were detected after 8 and 15 days of drought treatment, respectively, including numerous upregulated and downregulated genes. Gene Ontology (GO) enrichment analysis showed that the DEGs were primarily involved in various biological processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that carbon metabolism, glyoxylate and dicarboxylate metabolism, proteasome, glycine, serine, and threonine metabolism were the main affected pathways. Among the DEGs, 376 protein kinases, 42 proteases, 168 transcription factor (TF) genes, and 152 other potential functional genes were identified, which may play significant roles in the drought response of C. oleifera. The expression of relevant functional genes was further validated using quantitative real-time PCR (qRT-PCR). These findings contribute to the comprehension of drought tolerance mechanisms in C. oleifera and bolster the identification of drought-resistant genes for molecular breeding purposes. Full article

One of the main reasons for the low yield of Camellia oleifera Abel is the large number of flowers and fruits that fall off before ripening. The aim of this study was to investigate the effect of foliar spraying of potassium dihydrogen phosphate (KH₂PO₄) on the fruiting characteristics of C. oleifera, and to provide technical support for its flower and fruit preservation and yield increasing. Three C. oleifera cultivars, ‘Changlin 18’, ‘Changlin 166’, and ‘Changlin 40’, were used as experimental materials to conduct foliar spraying experiments with different water concentrations of KH₂PO₄. The effects of KH₂PO₄ on the fruit retention rate, fruit properties, and seed oil quality of each cultivar were measured and analyzed. The application of the optimal concentration of KH₂PO₄ significantly enhanced various fruit quality metrics of three C. oleifera cultivars. Specifically, the total fruit retention rate was increased by 30.02~87.53%, the transverse diameter by 7.36~21.21%, and the longitudinal diameter by 18.56%, and the fruit weight of ‘Changlin 40’ could increase by 83.63%. It also increased dry seed yield by 27.87~80.81%, dry kernel rate by 10.29~30.12%, dry seed oil content by 28.00~29.77%, total unsaturated fatty acids (TUFAs) by 0.63~5.3%, monounsaturated fatty acids (MUFAs) by 0.30~5.37%, and squalene by 0.09~0.14% during the maturing stage. However, camellia cultivars had the different responses to KH₂PO₄ concentrations. To promote the fruiting of C. oleifera, improve the economic traits of fruits, and enhance the quality of tea oil, the recommended concentrations of KH₂PO₄ solution are 4.50 g·L⁻¹, 1.50 g·L⁻¹, and 1.50 g·L⁻¹, for mist spraying on the trees of ‘Changlin 18’, ‘Changlin 166’, and ‘Changlin 40’, respectively. For mixed cultivars of C. oleifera which planted randomly, the recommended concentration range of KH₂PO₄ solution for spraying is 1.50 to 4.50 g·L⁻¹. Full article

Photoperiod is a pivotal regulatory factor in the flowering of Camellia oleifera Abel. (C. oleifera). GIGANTEA (GI) serves as a pivotal regulator, not only orchestrating the intricate circadian rhythm but also governing photoperiod-dependent flowering. In order to explore the function of GI in C. oleifera (CoGI), we obtained a CoGI gene-coding sequence and analyzed a CoGI protein sequence using bioinformatics. Furthermore, we conducted a spatiotemporal expression analysis of CoGI. And a yeast two-hybridization assay was used to screen the interacting proteins of CoGI. Evolutionary analysis revealed high conservation of the CoGI protein, which clustered with the GI protein from Camellia sinensis (CsGI) on a common evolutionary branch. The expression of CoGI was different in each part, and a tissue expression analysis revealed that the relative expression level of the CoGI gene is highest in the leaves of C. oleifera, while it is at its lowest in the seed coats. Transgenic Arabidopsis thaliana (Arabidopsis) overexpressing CoGI exhibited early flowering under long-day conditions. In addition, the yeast two-hybrid library screening revealed interactions between seven C. oleifera proteins and CoGI: CoACR9, CoLAO, CoDExH12-like, CoIT1K-like, CoUPF0481, CoIDM3, and CoAt4g27190-like. The findings demonstrated that CoGI is crucial to C. oleifera’s flowering. Full article

Tea saponins have high surface-active and biological activities and are widely used in chemicals, food, pharmaceuticals, and pesticides. Tea saponins are usually extracted using ethanol or water, but both methods have their disadvantages, including a negative impact on the environment, high energy consumption, and low purity. In this study, we explored an effective process for extracting tea saponins from tea meal using deep eutectic solvents combined with ultrasonic extraction and enzymatic techniques. The experimental results showed that a high extraction efficiency of 20.93 ± 0.48% could be achieved in 20 min using an ultrasonic power of 40% and a binary DES consisting of betaine and ethylene glycol (with a molar ratio of 1:3) at a material–liquid ratio of 1:35 and that the purity of the tea saponins after purification by a large-pore adsorption resin reached 95.94%, which was higher than that of commercially available standard tea saponin samples. In addition, the extracted tea saponins were evaluated for their antioxidant and bacteriostatic activities using chemical and biological methods; the results showed that the tea saponins extracted using these methods possessed antioxidant properties and displayed significant antibacterial activity. Therefore, the present study developed a method for using deep eutectic solvents as an environmentally friendly technological solution for obtaining high-purity tea saponins from tea meal oil. This is expected to replace the current organic solvent and water extraction process and has great potential for industrial development and a number of possible applications. Full article

Camellia seed oil (CSO), as a nutrient-rich edible oil, is widely used in foods, cosmetics, and other fields. In this work, the extraction, deacidification, decolorization, and deodorization processes of CSO were respectively optimized for meeting injectable oil standards. The results showed that the CSO extraction rate reached the highest level of 94% at optimized conditions (ultrasonic time, 31.2 min; reaction pH, 9.2; and reaction time, 3.5 h). The physicochemical indexes of CSO and 10 other vegetable oils were evaluated by the principal component analysis method, and the overall scores of vegetable oils were ranked as camellia seed oil > olive oil > rice oil > peanut oil > sesame oil > corn oil > soybean oil > sunflower oil > rapeseed oil > walnut oil > flaxseed oil. The physicochemical indicators of CSO were the most ideal among the 11 vegetable oils, which means that CSO is suitable as an injectable oil. Through the optimized processes of the deacidification, decolorization, and deodorization, the CSO acid value was reduced to 0.0515 mg KOH/g, the decolorization rate reached a maximum of 93.86%, and the OD₄₃₀ was 0.015, meeting the requirement (≤0.045 of OD₄₃₀) of injectable oil. After the deodorization process, these parameters of the refractive index, acid value, saponification value, iodine value, absorbance, unsaponifiable, moisture and volatiles, fatty acid composition, and heavy metal limits all met the pharmacopoeia standards of injectable oil in many countries and regions. The possibility of CSO as an injectable oil was first verified through refining-process optimization and nutritional index analysis, providing an important technical reference for the high-value utilization of vegetable oil. Full article

Spodoptera frugiperda (J.E. Smith) is a highly significant agricultural pest that poses a threat to crop production worldwide. It is polyphagous, has a strong migratory ability, and is difficult to control, which makes it a threat not only to crops but also to woody plants. However, research on its adaptability to woody plants is limited. This study compares the feeding adaptations (survival rate, pupation time, pupation rate, weight, length, and daily food consumption), protective enzyme activities, and feeding preferences of S. frugiperda on leaves of six economically important tree species (Areca catechu L., Aquilaria sinensis (Lour.) Spreng, Cocos nucifera L., Camellia oleifera Abel, Dalbergia odorifera T. Chen, and Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg.), with Zea mays L. used as a control treatment. The results indicate that S. frugiperda did not survive when fed with A. catechu, C. oleifera, and D. odorifera. A. catechu had similar survival rates (83.33%), pupation (86.67%), weight, and length data compared to the maize control. C. nucifera had lower survival rates (46.67%) but no significant differences in pupation (76.67%), weight, and length data of S. frugiperda. H. brasiliensis exhibited significantly lower survival (50.00%) and pupation rates (46.67%) compared to maize. However, there was no significant difference in weight and length data, and its preference index was higher among the six tree species treatments. Therefore, A. sinensis is a vulnerable tree with a high risk, while H. brasiliensis and C. nucifera showed varying degrees of susceptibility. A. catechu, C. oleifera, and D. odorifera were found to be unsuitable hosts for S. frugiperda. In conclusion, this study extensively explores the feeding effects of S. frugiperda on six economically important tree species. It provides insights into the feeding preferences of the pest, thereby informing the potential threat posed by S. frugiperda to economically important trees. It helps to prevent further damage from S. frugiperda and provides a reference for agriculture and forestry to develop effective joint prevention and control measures. Full article