摘要：
Maintaining permanent forest canopy cover and eventually harvesting timber by predetermined target diameter are often considered as a prototype for future management of the oak natural forest. However, target diameters and harvest age based on average forest growth rates from wide geographical areas often hamper improved management of oak forests. In this study, based on the sampling of 129 target trees from 51 oak natural secondary forest plots in Hunan Province, China, an individual-tree DBH (diameter at breast height) growth model of oak target trees was developed, and the site type (41 levels) was related to the model as random effects by a nonlinear mixed-effects approach. Moreover, the 41 site types were clustered into four site type groups (STG1, STG2, STG3, and STG4) by the K-means clustering algorithm to improve the model performance and practicality. With the help of the model, the five target diameters (including 24, 30, 40, 50, and 60 cm) were simulated in each of the four STGs, and the minimum target diameter was determined for each STG based on the theory of quantitative maturity. In the four STGs, the harvest age of the 24 cm diameter target ranged from 30 to 51 years; the harvest age of the 60 cm target diameter ranged from 131 to 220 years, with the oaks failing to reach 60 cm in the lowest-quality STG4; the minimum target diameter ranged from 21 cm to 29 cm. Results showed that lower-quality sites exclude higher target diameters from optimal harvesting strategies, in contrast to the higher target diameter as a more reasonable strategy in higher quality sites, and that the minimum target diameter is significantly influenced by site conditions. Therefore, it is necessary to develop a diverse target-diameter-harvesting strategy adapted for the complex site conditions of oak forests in Hunan Province towards site-specific timber management to improve the sustainability of timber production in oak forests.
期刊：
Journal of Soils and Sediments,2024年:1-14 ISSN：1439-0108
通讯作者：
Sheng Lu
作者机构：
[Yukun Lu; Qi Sun; Qin Deng; Sheng Lu] Key Laboratory of Soil and Water Conservation and Desertification Combating in Hunan Province, College of Forestry, Central South University of Forestry and Technology, Changsha, People’s Republic of China;[Zipei Luo] National Engineering Laboratory of Applied Technology for Forestry & Ecology in Southern China, Central South University of Forestry and Technology, Changsha, People’s Republic of China;[Jun Yuan] Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of National Ministry of Education, College of Forestry, Central South University of Forestry and Technology, Changsha, People’s Republic of China;[Jiayuan Liao] School of Atmospheric Sciences, Sun Yat-Sen University, and, Southern MarineScience and Engineering GuangdongLaboratory (Zhuhai), Zhuhai, People’s Republic of China;[Lichao Wu] Key Laboratory of Soil and Water Conservation and Desertification Combating in Hunan Province, College of Forestry, Central South University of Forestry and Technology, Changsha, People’s Republic of China<&wdkj&>Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of National Ministry of Education, College of Forestry, Central South University of Forestry and Technology, Changsha, People’s Republic of China
通讯机构：
[Sheng Lu] K;Key Laboratory of Soil and Water Conservation and Desertification Combating in Hunan Province, College of Forestry, Central South University of Forestry and Technology, Changsha, People’s Republic of China
关键词：
Camellia oleifera;Macro and microelements;Stoichiometry;Bioaccumulation factor;Translocation factor
摘要：
Understanding the accumulation rule of nutrients is crucial to promote the production of Camellia oleifera. The stoichiometry of soil macro and microelements is more critical than their content in affecting the growth and yield of plants. However, research on C. oleifera in these aspects is limited. In this study, we examined microelement content in soil and various parts of the C. oleifera plant and analyzed the relationship between the bioaccumulation, distribution, and production of plant macro and microelements with the stoichiometry of soil macro and microelements. Our findings indicated that high-yield plants transported more Ca, Mg, and B to the shoot, while low-yield plants stored higher Fe, Zn, and Al in the root. The significantly lower bioaccumulation factor and translocation factor of B and Mg in the high-yield plants highlighted the importance of nutrient storage in promoting C. oleifera yield. Multiple regression analysis and the Mantel test demonstrated that plant yield and bioaccumulation and transportation of macro and microelements were more closely correlated with the stoichiometry of macro and microelements than their content. The significantly different stoichiometry of macro and microelements in soil of different yields revealed that the stoichiometry of macro and microelements was more sensitive and reliable in reflecting the balance in soil nutrients of C. oleifera and regulating its growth. This study provides a comprehensive understanding of the balance in soil macro and microelements and their relationship with the growth of C. oleifera and highlights the critical role of the stoichiometry of soil macro and microelements in promoting high and stable production of C. oleifera.
摘要：
Crossing Wolbachia‐infected males with uninfected females reduced the hatching rate by 28% compared with that when infected males were crossed with infected females. The number of eggs laid by Wolbachia‐free females was significantly lower than laid by infected females. Wolbachia had a dual effect on Velarifictorus aspersus reproduction, inducing incomplete cytoplasmic incompatibility and promoting the fertility of infected females. Abstract Wolbachia is a maternally inherited endosymbiont of the phylum α‐Proteobacteria that is found widely in arthropods and nematodes. Cytoplasmic incompatibility (CI) is the commonest endosymbiotic manipulation among arthropods, namely reduced embryo viability when Wolbachia‐infected males fertilize Wolbachia‐uninfected females. In this study, endosymbiont infection was investigated and crossing experiments were performed in the wing‐dimorphic cricket Velarifictorus aspersus (Walker) (Orthoptera: Gryllidae) to clarify the effects of Wolbachia on host reproduction. All the tested individuals were infected with two Wolbachia strains, wAsp‐a and wAsp‐f, which belong to supergroup A and supergroup F, respectively. There were no obvious differences in the duration of nymph development or the proportions of females between the Wolbachia‐infected and Wolbachia‐free lines. However, crossing Wolbachia‐infected males with uninfected females reduced the hatching rate by 28% compared with that when infected males were crossed with infected females. The number of eggs laid by Wolbachia‐free females was significantly lower than laid by infected females, either mating with infected males or uninfected males. These results suggest that Wolbachia induced incomplete CI and enhanced female fertility in V. aspersus. Because no homologous cifA and cifB genes, which are involved in CI, were found in supergroups C, D and F, it might be considered that the CI of V. aspersus was induced by strain wAsp‐a of supergroup A. Moreover, the significant increase in the density of wAsp‐a Wolbachia with nymph development might be related to the regulation of CI.
作者机构：
[Cao, Yunpeng; Cao, YP] Chinese Acad Sci, CAS Key Lab Plant Germplasm Enhancement & Specialt, Wuhan Bot Garden, Wuhan 430074, Peoples R China.;[Cao, Yunpeng; Cao, YP; Zhang, Lin; Zhang, L] Wuchang Univ Technol, Sch Hlth & Nursing, Wuhan, Peoples R China.;[Li, XX; Li, Xiaoxu] Beijing Life Sci Acad, Beijing 102209, Peoples R China.;[Zhang, Lin; Zhang, L] Hubei Univ Chinese Med, Sch Basic Med Sci, Hubei Shizhen Lab, Wuhan 430065, Peoples R China.;[Lin, Mengfei; Lin, MF] Jiangxi Acad Sci, Inst Biol Resources, Nanchang 330224, Jiangxi, Peoples R China.
通讯机构：
[Cao, YP; Zhang, L ] W;[Cao, YP ] C;[Lin, MF ] J;[Li, XX ] B;Chinese Acad Sci, CAS Key Lab Plant Germplasm Enhancement & Specialt, Wuhan Bot Garden, Wuhan 430074, Peoples R China.
关键词：
NBS-LRR;Tung tree;Functional;VIGS;Fusarium
摘要：
Most disease resistance (R) genes in plants encode proteins that contain leucine-rich-repeat (LRR) and nucleotide-binding site (NBS) domains, which belong to the NBS-LRR family. The sequenced genomes of Fusarium wilt-susceptible Vernicia fordii and its resistant counterpart, Vernicia montana, offer significant resources for the functional characterization and discovery of novel NBS-LRR genes in tung tree. Here, we identified 239 NBS-LRR genes across two tung tree genomes: 90 in V. fordii and 149 in V. montana. Five VmNBS-LRR paralogous were predicted in V. montana, and 43 orthologous were detected between V. fordii and V. montana. The orthologous gene pair Vf11G0978-Vm019719 exhibited distinct expression patterns in V. fordii and V. montana: Vf11G0978 showed downregulated expression in V. fordii, while its orthologous gene Vm019719 demonstrated upregulated expression in V. montana, indicating that this pair may be responsible for the resistance to Fusarium wilt in V. montana. Vm019719 from V. montana, activated by VmWRKY64, was shown to confer resistance to Fusarium wilt in V. montana by a virus-induced gene silencing (VIGS) experiment. However, in the susceptible V. fordii, its allelic counterpart, Vf11G0978, exhibited an ineffective defense response, attributed to a deletion in the promoter’s W-box element. This study provides the first systematic analysis of NBS-LRR genes in the tung tree and identifies a candidate gene that can be utilized for marker-assisted breeding to control Fusarium wilt in V. fordii.
关键词：
Bottom-up control;Carbon flow;Enzymatic activities;Legume intercropping;Nitrogen fertilization;Soil nematode food web
摘要：
Excessive nitrogen (N) loading poses a substantial risk to soil biodiversity and disrupts carbon (C) flows within the soil food web. Intercropping with legumes is often considered a sustainable way to maintain soil N availability and mitigate the associated detrimental effects. However, it remains unclear whether and how legume crops restore energetic attenuation caused by N loading within the soil food web. Here, we conducted a two-year field experiment using randomized block design in a subtropic Camellia oleifera plantation with high wet N deposition. We examined the effects of applying N fertilizers at normal or half levels (168 or 84kgN ha(-1)yr(-1)) and intercropping legumes (Arachis hypogaea or Cassia tora) on the soil nematode food web. We observed that N fertilization suppressed the majority of nematode trophic groups, weakened the stability of food web structure, and diminished the C flows across the bacterial and fungal energy channels. Conversely, intercropping with legumes (particularly with C. tora) bolstered the densities of bacterivore and fungivore nematodes. This enhancement facilitated interactions within the soil micro-food web, and subsequently augmented the C flows within their respective channels. Model predictions suggested that the detrimental effects of N fertilizers on the nematode food web are primarily linked to decreased soil pH resulting from soil N accumulation. Notably, higher soil organic C was found to mitigate these effects. Furthermore, N-enriched legume substrates played a beneficial role in stimulating soil microbial activities and facilitating C flows through bottom-up control. Our findings emphasize the positive impacts of legume crops on mitigating soil biodiversity loss and restoring energetic attenuation within soil food web under N-saturated soil conditions. These findings provide valuable insights for agroforestry management practices aimed at sustaining soil health and ecosystem resilience.
摘要：
Oxygen is one of the determinants of root microbiome formation. However, whether plants regulate rhizosphere oxygen levels to affect microbiota composition and the underlying molecular mechanisms remain elusive. The receptor-like kinase (RLK) family member FERONIA modulates the growth-defense tradeoff in Arabidopsis. Here, we established that rice FERONIA-like RLK 7 (FLR7) controls rhizosphere oxygen levels by methylene blue staining, oxygen flux and potential measurements. The formation of oxygen-transporting aerenchyma in roots is negatively regulated by FLR7. We further characterized the root microbiota of 11 FLR mutants including flr7 and wild-type Nipponbare (Nip) grown in the field by 16S ribosomal RNA gene profiling and demonstrated that the 11 FLRs are involved in regulating rice root microbiome formation. The most abundant anaerobic-dependent genus Anaeromyxobacter in the Nip root microbiota was less abundant in the root microbiota of all these mutants, and this contributed the most to the community differences between most mutants and Nip. Metagenomic sequencing revealed that flr7 increases aerobic respiration and decreases anaerobic respiration in the root microbiome. Finally, we showed that a representative Anaeromyxobacter strain improved submergence tolerance in rice via FLR7. Collectively, our findings indicate that FLR7 mediates changes in rhizosphere oxygen levels and enriches the beneficial dominant genus Anaeromyxobacter and may provide insights for developing plant flood prevention strategies via the use of environment-specific functional soil microorganisms.
作者机构：
[Liu, Qin; Xue, Tian-Tian; Yu, Sheng-Xiang; Liang, Yun-Fen; Chen, Tian-Xiang; Han, Bao-Cai; Qin, Fei; Zhang, Wen-Di] Chinese Acad Sci, Inst Bot, State Key Lab Systemat & Evolutionary Bot, Beijing, Peoples R China.;[Xue, Tian-Tian; Yu, Sheng-Xiang; Liang, Yun-Fen; Chen, Tian-Xiang; Han, Bao-Cai; Qin, Fei; Zhang, Wen-Di] Univ Chinese Acad Sci, Beijing, Peoples R China.;[Xue, Tian-Tian; Yu, Sheng-Xiang; Liang, Yun-Fen; Chen, Tian-Xiang; Han, Bao-Cai; Qin, Fei; Zhang, Wen-Di] China Natl Bot Garden, Beijing, Peoples R China.;[Liu, Qin] Cent South Univ Forestry & Technol, Coll Forestry, Changsha, Peoples R China.;[Bussmann, Rainer W.] Ilia State Univ, Inst Bot, Tbilisi, Georgia.
通讯机构：
[Yu, SX ] C;Chinese Acad Sci, Inst Bot, State Key Lab Systemat & Evolutionary Bot, Beijing, Peoples R China.;Univ Chinese Acad Sci, Beijing, Peoples R China.;China Natl Bot Garden, Beijing, Peoples R China.
关键词：
distribution patterns;ensemble model;influencing factors;invasive alien plants;linear mixed-effect model;potential distribution areas
摘要：
Invasive alien plants (IAPs) have serious environmental and economic impacts, especially in vulnerable areas of China. However, IAP richness distribution patterns, their driving factors, and the dynamic shifts in potential distribution areas remain elusive. We assessed IAP richness distribution patterns and drivers using 402 IAPs recorded in China at 88 926 occurrence points, and then predicted their potential distribution areas. The results show that IAP hotspots were mainly located in southeastern China, especially coastal areas of the South and East and large inland cities. Population density, gross domestic product (GDP), and four climate variables associated with precipitation and temperature jointly influenced the richness distribution pattern of all IAPs. Specifically, population density and GDP impacted the richness distribution pattern of narrow‐range IAPs, and population density, GDP, distance to the nearest national highway, and five climate variables affected the richness distribution pattern of widespread IAPs. Only GDP contributed significantly to the richness distribution pattern of the top 5% hotspot grid cells, whereas population density, GDP, and precipitation in the driest month (BIO14) significantly influenced the richness distribution patterns of hotspots for both the top 10% and top 20%. Prediction analysis demonstrated that southeastern China would have particularly high invasion risk under both current and future climate scenarios. Regions with increases in predicted species richness are more common (44.83–64.97%) than those with decreases, except under the Representative Concentration Pathway (RCP) 4.5 scenario. Climate change will contribute greatly to the expansion of potential IAP distribution areas under both optimistic (RCP 2.5) and pessimistic scenarios (RCP 8.5). The results of this study provide insights into the priority management of IAPs by developing promising strategies for the control and prevention of IAP invasion.
作者机构：
Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China;Hunan Key Laboratory of Colleges and Universities of Oil Tea Breeding, Central South University of Forestry and Technology, Changsha 410004, China;Author to whom correspondence should be addressed.;[Feng Zou] Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Key Laboratory of Colleges and Universities of Oil Tea Breeding, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.;[Jiawei Ye; Huan Xiong; Deyi Yuan; Xiaolei Gao; Ying Yang] Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Key Laboratory of Colleges and Universities of Oil Tea Breeding, Central South University of Forestry and Technology, Changsha 410004, China
通讯机构：
[Feng Zou] K;Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Key Laboratory of Colleges and Universities of Oil Tea Breeding, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
cytoplasmic male sterility;petaloid anther;calcium homeostasis;ROS metabolism;tapetal PCD;gene expression;Camellia oleifera
摘要：
Cytoplasmic male sterility (CMS) plays a crucial role in the utilization of heterosis. The petaloid anther abortion in oil tea (Camellia oleifera Abel.) constitutes a CMS phenomenon, which is of great value for the hybrid breeding of oil tea. However, as the mechanism of its CMS is still poorly understood, it is necessary to study the cytology and physiological characteristics of anther abortion. In this study, a C. oleifera cultivar, Huashuo (HS), and its petalized CMS mutant (HSP) were used as materials to explore this mechanism. Compared with HS, cytological analysis demonstrated that HSP showed early-onset tapetum programmed cell death (PCD) and an organelle disorder phenotype during the tetrad stage. In HSP, anthers exhibited elevated levels of calcium deposition in anther wall tissues, tapetum layers, and microspores, and yet calcium accumulation was abnormal at the later stage. The contents of hydrogen peroxide and MDA in HSP anthers were higher, and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were lower than those of HS, which resulted in an excessive accumulation of reactive oxygen species (ROS). Real-time quantitative PCR confirmed that the transcription levels of CoPOD and CoCAT genes encoding key antioxidant enzymes in HSP were downregulated compared with HS in early pollen development; the gene CoCPK, which encodes a calcium-dependent protein kinase associated with antioxidase, was upregulated during the critical period. Thus, we suggest that excessive ROS as a signal breaks the balance of the antioxidant system, and along with an abnormal distribution of calcium ions, leads to the early initiation of PCD in the tapetum, and ultimately leads to pollen abortion for HSP. These results lay a cytological and physiological foundation for further studies on the CMS mechanism, and provide information for breeding male-sterile lines of C. oleifera.
作者：
Sen Wang;Song Sheng;Jiqing Peng;Hanyu Fu;Fengxia Shao;...
期刊：
Agronomy,2024年14(3):576- ISSN：2073-4395
通讯作者：
Sen Wang<&wdkj&>Song Sheng
作者机构：
These authors contributed equally to this work.;[Hanyu Fu] College of Forestry, Central South University of Forestry & Technology, 498 South Shaoshan Road, Changsha 410004, China;Yuelushan Laboratory, Qiushi Building, Hunan Agricultural University, Furong District, Changsha 410128, China;The Belt and Road International Union Research Center for Tropical Arid Non-Wood Forest in Hunan Province, 498 South Shaoshan Road, Changsha 410004, China;Authors to whom correspondence should be addressed.
通讯机构：
[Sen Wang; Song Sheng] A;Authors to whom correspondence should be addressed.<&wdkj&>College of Forestry, Central South University of Forestry & Technology, 498 South Shaoshan Road, Changsha 410004, China<&wdkj&>Yuelushan Laboratory, Qiushi Building, Hunan Agricultural University, Furong District, Changsha 410128, China<&wdkj&>The Belt and Road International Union Research Center for Tropical Arid Non-Wood Forest in Hunan Province, 498 South Shaoshan Road, Changsha 410004, China
摘要：
The biosynthesis and distribution of lignans in medicinal plants, particularly in Schisandra sphenanthera, hold significant pharmacological importance. This study bridges the knowledge gap in understanding the tissue-specific biosynthesis and distribution of these compounds, with a focus on Gomisin J. Our phytochemical analysis revealed a distinct accumulation pattern of Gomisin J, predominantly in the roots, contrasting with the distribution of Pregomisin and Dihydroguaiaretic acid. This finding highlights the roots’ unique role in lignan storage and biosynthesis. Further, differential gene expression analysis across various tissues illuminated the biosynthetic pathways and regulatory mechanisms of these lignans. Utilizing Weighted Gene Co-expression Network Analysis (WGCNA), we identified the MEtan module as a key player, strongly correlated with Gomisin J levels. This module’s in-depth examination revealed the crucial involvement of four cytochrome P450 (CYP) enzymes and eight transcription factors. Notably, the CYP genes DN6828 and DN2874-i3 exhibited up-regulation in roots across both male and female plants, while DN51746 was specifically up-regulated in male roots, indicating a potential gender-specific aspect in Gomisin J biosynthesis. Comparative analysis with functionally characterized CYP71A homologs suggests these CYP genes might be involved in distinct biosynthetic pathways, including terpenoids, alkaloids, and phenylpropanoids, and potentially in lignan biosynthesis. This hypothesis, supported by their more than 55% identity with CYP71As and strong correlation with Gomisin J concentration, opens avenues for novel discoveries in lignan biosynthesis, pending further functional characterization. Our research provides a comprehensive understanding of the genetic and metabolic mechanisms underlying the tissue-specific distribution of lignans in Schisandra sphenanthera, offering valuable insights for their pharmacological exploitation.
作者机构：
[Xue, Jun; Yang, Yanjie; Liao, Xiaowen; Shang, Chao; Wu, Lei] College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China Central South University of Forestry and Technology Changsha China;[Liu, Quanru] College of Life Sciences, Beijing Normal University, Beijing 100875, Beijing, China Beijing Normal University Beijing China
摘要：
Ophiorrhizareflexa, a new species from Guangxi, China, is described and illustrated in this study. It is morphologically similar to O.alatiflora due to the branched inflorescence, distylous flowers and the tubular-funnelform corolla with five longitudinal wings. The new species can be distinguished from O.alatiflora by its erect inflorescence, its smaller and equal-sized calyx lobes 0.5-0.7 mm long, its corolla tubes winged to the middle and the wings straight and its strongly reflexed corolla lobes at anthesis. Ophiorrhizareflexa is assessed as least concern (LC) according to IUCN Categories and Criteria.
作者机构：
[Wang, Songwei; Tian, Daike; Li, Xin; Tian, DK] Shanghai Chenshan Bot Garden, Chenshan Res Ctr, CAS Ctr Excellence Mol Plant Sci, Shanghai 201602, Peoples R China.;[Wang, Songwei; Tian, Daike; Wei, Hongjing; Li, Xin; Tian, DK] Shanghai Chenshan Bot Garden, Eastern China Conservat Ctr Wild Endangered Plant, Shanghai 201602, Peoples R China.;[Huang, Cunzhong] Nat Resources Bur Guidong Cty, Chenzhou 423000, Hunan, Peoples R China.;[Wu, Lei] Cent South Univ Forestry & Technol, Coll Forestry, Changsha 410004, Hunan, Peoples R China.;[Chen, Zhilin] Guizhou Acad Agr Sci, Hort Res Inst, Guiyang 550025, Guizhou, Peoples R China.
通讯机构：
[Tian, DK ] S;Shanghai Chenshan Bot Garden, Chenshan Res Ctr, CAS Ctr Excellence Mol Plant Sci, Shanghai 201602, Peoples R China.;Shanghai Chenshan Bot Garden, Eastern China Conservat Ctr Wild Endangered Plant, Shanghai 201602, Peoples R China.
关键词：
WORDS;Begonia ruchengensis;Begonia auritalata;new taxa;taxonomy;flora of China;morphology;conservation
摘要：
China has an exceptional diversity in Begonia, holding the second largest number of described species in this genus at the national level. Many new taxa need to be explored and described. This paper reports two new species, Begonia ruchengensis (B. sect. Reichenheimia) and B. auritalata (B. sect. Platycentrum), from Hunan province and Guizhou province, respectively. Besides the detailed morphology description, color illustrations, and line drawings, the diagnoses of these two species distinguished from their allied taxa are provided. Their conservation statuses are evaluated according to The Guidelines for Using the IUCN Red List Categories.
摘要：
Cinnamomum plants are rich in natural essential oils, which are widely used as materials in the fragrance, insecticidal, antibacterial agent, pharmaceutical, and food industries; however, few studies have investigated the essential oil components of Cinnamomum bodinieri. Therefore, this study investigated the diversity of essential oils from the leaves of 885 individual C. bodinieri plants across 32 populations in five provinces. Essential oils were extracted by hydrodistillation, and then qualitative and quantitative analyses of the compounds were performed by GC-MS and GC-FID. A total of 87 chemical constituents were identified in the essential oils, including 33 monoterpenes, 48 sesquiterpenes, and six other compounds. The average oil yield was 0.75%, and individual oil yields ranged from 0.01% to 4.28%. A total of 16 chemotypes were classified according to variations in the essential oil chemical constituents of C. bodinieri, among which the camphor-type, citral-type, and eucalyptol-type were dominant. Moreover, the borneol-type, cymol-type, elemol-type, methylisoeugenol-type, and selina-6-en-4-ol-type were reported in C. bodinieri for the first time. The yield and principal components of the essential oils were mainly affected by altitude, temperature, and sunshine duration, among which altitude had the most significant effect; thus, low-altitude areas are more suitable for the synthesis and accumulation of essential oils. Based on the different characteristics of the essential oils in the leaves of C. bodinieri, several excellent populations and individuals were identified in this study. Moreover, the findings provide a foundation for breeding superior varieties and studying essential oil biosynthesis mechanisms in the future.
摘要：
Anthracnose is a common disease found in Camellia oleifera producing areas across China, whose primary pathogen is Colletotrichum fructicola. We previously revealed that autophagy is essential for the pathogenicity of C. fructicola. However, the function of ubiquitin-proteasome system (UPS), which is a parallel protein degradation pathway to autophagy, remains elusive. Here, we report that CfRad6, an E2 conjugating enzyme in UPS, interacts with three putative E3 ubiquitin ligases, namely CfRad18, CfUbr1, and CfBre1. Importantly, we presented evidence showing that CfRad6 negatively regulates autophagy, revealing the first link between UPS and autophagy in pathogenic fungi. Targeted gene deletion showed that CfRad6 is involved in growth and conidiation. We further found that the Delta Cfrad6 mutant is defective in appressoria formation and responses to environmental stresses. These combined effects, along with the abnormal autophagy level, lead to the pathogenicity defects of the Delta Cfrad6 mutant. Taken together, our study indicates the pleiotropic functions of CfRad6 in the development and pathogenicity of C. fructicola.
