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Liu J, Chen H, Lv Y, Wu H, Yang LJ, Zhang J, Huang J, Wang W. Synthesis, Characterization, and Antifungal Activity of Benzimidazole-Grafted Chitosan against Aspergillus flavus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:11185-11194. [PMID: 38687832 DOI: 10.1021/acs.jafc.4c01010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Aspergillus flavus contamination in agriculture and food industries poses threats to human health, leading to a requirement of a safe and effective method to control fungal contamination. Chitosan-based nitrogen-containing derivatives have attracted much attention due to their safety and enhanced antimicrobial applications. Herein, a new benzimidazole-grafted chitosan (BAC) was synthesized by linking the chitosan (CS) with a simple benzimidazole compound, 2-benzimidazolepropionic acid (BA). The characterization of BAC was confirmed by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance spectroscopy (1H and 13C NMR). Then, the efficiency of BAC against A. flavus ACCC 32656 was investigated in terms of spore germination, mycelial growth, and aflatoxin production. BAC showed a much better antifungal effect than CS and BA. The minimum inhibitory concentration (MIC) value was 1.25 mg/mL for BAC, while the highest solubility of CS (16.0 mg/mL) or BA (4.0 mg/mL) could not completely inhibit the growth of A. flavus. Furthermore, results showed that BAC inhibited spore germination and elongation by affecting ergosterol biosynthesis and the cell membrane integrity, leading to the permeabilization of the plasma membrane and leakage of intracellular content. The production of aflatoxin was also inhibited when treated with BAC. These findings indicate that benzimidazole-derived natural CS has the potential to be used as an ideal antifungal agent for food preservation.
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Affiliation(s)
- Jing Liu
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, PR. China
| | - Hao Chen
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, PR. China
| | - Yan Lv
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, PR. China
| | - Huixiang Wu
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, PR. China
| | - Li-Jun Yang
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, PR. China
| | - Jiahui Zhang
- Hangzhou Sanyan Biotechnology Co., Ltd., Hangzhou, Zhejiang 310018, PR. China
- Xiuzheng Bio-Medicine Research Institute Co., Ltd., Hangzhou, Zhejiang 310018, PR. China
| | - Jianying Huang
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, PR. China
| | - Wenjie Wang
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, PR. China
- Hangzhou Sanyan Biotechnology Co., Ltd., Hangzhou, Zhejiang 310018, PR. China
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Pan X, Hao L, Yang C, Lin H, Wu D, Chen X, Zhang M, Ma D, Wang Y, Fu W, Yao Y, Wang S, Zhuang Z. SWD1 epigenetically chords fungal morphogenesis, aflatoxin biosynthesis, metabolism, and virulence of Aspergillus flavus. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131542. [PMID: 37172387 DOI: 10.1016/j.jhazmat.2023.131542] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/17/2023] [Accepted: 04/28/2023] [Indexed: 05/14/2023]
Abstract
As the main producer of aflatoxins, Aspergillus flavus is also one of the most important causes of invasive and non-invasive aspergillosis. Therefore, it is crucial to unravel the regulatory mechanisms of growth, metabolism, and pathogenicity of A. flavus. SWD1 is highly conserved across species for maintaining COMPASS methyltransferase activity, but the bio-function of SWD1 in A. flavus has not been explored. Through genetic analysis, this study revealed that SWD1 is involved in fungal morphogenesis and AFB1 biosynthesis by regulating the orthodox pathways through H3K4me1-3. Stresses sensitivity and crop models analysis revealed that SWD1 is a key regulator for the resistance of A. flavus to adapt to extreme adverse environments and to colonize crop kernels. It also revealed that the WD40 domain and 25 aa highly conserved sequence are indispensable for SWD1 in the regulation of mycotoxin bio-synthesis and fungal virulence. Metabolomic analysis inferred that SWD1 is crucial for the biosynthesis of numerous primary and secondary metabolites, regulates biological functions by reshaping the whole metabolic process, and may inhibit fungal virulence by inducing the apoptosis of mycelia through the inducer sphingosine. This study elucidates the epigenetic mechanism of SWD1 in regulating fungal pathogenicity and mycotoxin biosynthesis, and provides a potential novel target for controlling the virulence of A. flavus.
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Affiliation(s)
- Xiaohua Pan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian Key Laboratory of Propagated Sensation along Meridian, Fujian Academy of Chinese Medical Sciences, Fuzhou 350003, China
| | - Ling Hao
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Chi Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Edible Mushroom, Fujian Academy of Agricultural Sciences, Fuzhou 350014, China
| | - Hong Lin
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Dandan Wu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xuan Chen
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Mengjuan Zhang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Dongmei Ma
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yu Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wangzhuo Fu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yanfang Yao
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Zhenhong Zhuang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Wang J, Liang L, Wei S, Zhang S, Hu Y, Lv Y. Histone 2-Hydroxyisobutyryltransferase Encoded by Afngg1 Is Involved in Pathogenicity and Aflatoxin Biosynthesis in Aspergillus flavus. Toxins (Basel) 2022; 15:7. [PMID: 36668827 PMCID: PMC9861817 DOI: 10.3390/toxins15010007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/07/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Aflatoxin, a carcinogenic secondary metabolite produced by Aspergillus flavus, is a significant threat to human health and agricultural production. Histone 2-hydroxyisobutyrylation is a novel post-translational modification that regulates various biological processes, including secondary metabolism. In this study, we identified the novel histone 2-hydroxyisobutyryltransferase Afngg1 in A. flavus, and explored its role in cell growth, development and aflatoxin biosynthesis. Afngg1 gene deletion markedly decreased lysine 2-hydroxyisobutyrylation modification of histones H4K5 and H4K8 compared with the control strain. Additionally, Afngg1 deletion inhibited mycelial growth of A. flavus, and the number of conidia and hydrophobicity were significantly decreased. Notably, aflatoxin B1 biosynthesis and sclerotia production were completely inhibited in the ΔAfngg1 strain. Furthermore, the pathogenicity of the ΔAfngg1 strain infecting peanut and corn grains was also diminished, including reduced spore production and aflatoxin biosynthesis compared with A. flavus control and Afngg1 complementation strains. Transcriptome analysis showed that, compared with control strains, differentially expressed genes in ΔAfngg1 were mainly involved in chromatin remodelling, cell development, secondary metabolism and oxidative stress. These results suggest that Afngg1 is involved in histone 2-hydroxyisobutyrylation and chromatin modification, and thus affects cell development and aflatoxin biosynthesis in A. flavus. Our results lay a foundation for in-depth research on the 2-hydroxyisobutyrylation modification in A. flavus, and may provide a novel target for aflatoxin contamination prevention.
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Affiliation(s)
- Jing Wang
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Liuke Liang
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Shan Wei
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Shuaibing Zhang
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Yuansen Hu
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Yangyong Lv
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
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Liang L, Yang H, Wei S, Zhang S, Chen L, Hu Y, Lv Y. Putative C 2H 2 Transcription Factor AflZKS3 Regulates Aflatoxin and Pathogenicity in Aspergillus flavus. Toxins (Basel) 2022; 14:toxins14120883. [PMID: 36548780 PMCID: PMC9786134 DOI: 10.3390/toxins14120883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Aflatoxin is a carcinogenic secondary metabolite that poses a serious threat to human and animal health. Some C2H2 transcription factors are associated with fungal growth and secondary metabolic regulation. In this study, we characterized the role of AflZKS3, a putative C2H2 transcription factor based on genome annotation, in the growth and aflatoxin biosynthesis of A. flavus and explored its possible mechanisms of action. Surprisingly, the protein was found to be located in the cytoplasm, and gene deletion in A. flavus resulted in defective growth and conidia formation, as well as increased sensitivity to the fluorescent brightener Calcofluor white, Congo red, NaCl, and sorbitol stress. Notably, the biosynthesis of aflatoxin B1 was completely inhibited in the ΔAflZKS3 deletion strain, and its ability to infect peanut and corn seeds was also reduced. RNA sequencing showed that differentially expressed genes in the ΔAflZKS3 strain compared with the control and complementation strains were mainly associated with growth, aflatoxin biosynthesis, and oxidative stress. Thus, AflZKS3 likely contributes to growth, cell development, and aflatoxin synthesis in A. flavus. These findings lay the foundation for a deeper understanding of the roles of C2H2 transcription factors in A. flavus and provide a potential biocontrol target for preventing aflatoxin contamination.
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The Plant Homeodomain Protein Clp1 Regulates Fungal Development, Virulence, and Autophagy Homeostasis in Magnaporthe oryzae. Microbiol Spectr 2022; 10:e0102122. [PMID: 36036638 PMCID: PMC9602895 DOI: 10.1128/spectrum.01021-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Rice blast disease caused by Magnaporthe oryzae is a serious threat to global grain yield and food security. Cti6 is a nuclear protein containing a plant homeodomain (PHD) that is involved in transcriptional regulation in Saccharomyces cerevisiae. The biological function of its homologous protein in M. oryzae has been elusive. Here, we report Clp1 with a PHD domain in M. oryzae, a homologous protein of the yeast Cti6. Clp1 was mainly located in the nucleus and partly in the vesicles. Clp1 colocalized and interacted with the autophagy-related proteins Atg5, Atg7, Atg16, Atg24, and Atg28 at preautophagosomal structures (PAS) and autophagosomes, and the loss of Clp1 increased the fungal background autophagy level. Δclp1 displayed reduced hyphal growth and hyperbranching, abnormal fungal morphology (including colony, spore, and appressorium), hindered appressorial glycogen metabolism and turgor production, weakened plant infection, and decreased virulence. The PHD is indispensable for the function of Clp1. Therefore, this study revealed that Clp1 regulates development and pathogenicity by maintaining autophagy homeostasis and affecting gene transcription in M. oryzae. IMPORTANCE The fungal pathogen Magnaporthe oryzae causes serious diseases of grasses such as rice and wheat. Autophagy plays an indispensable role in the pathogenic process of M. oryzae. Here, we report a Cti6-like protein, Clp1, that is involved in fungal development and infection of plants through controlling autophagy homeostasis in the cytoplasm and gene transcription in the nucleus in M. oryzae. This study will help us to understand an elaborated molecular mechanism of autophagy, gene transcription, and virulence in the rice blast fungus.
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Cho HJ, Son SH, Chen W, Son YE, Lee I, Yu JH, Park HS. Regulation of Conidiogenesis in Aspergillus flavus. Cells 2022; 11:cells11182796. [PMID: 36139369 PMCID: PMC9497164 DOI: 10.3390/cells11182796] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/29/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Aspergillus flavus is a representative fungal species in the Aspergillus section Flavi and has been used as a model system to gain insights into fungal development and toxin production. A. flavus has several adverse effects on humans, including the production of the most carcinogenic mycotoxin aflatoxins and causing aspergillosis in immune-compromised patients. In addition, A. flavus infection of crops results in economic losses due to yield loss and aflatoxin contamination. A. flavus is a saprophytic fungus that disperses in the ecosystem mainly by producing asexual spores (conidia), which also provide long-term survival in the harsh environmental conditions. Conidia are composed of the rodlet layer, cell wall, and melanin and are produced from an asexual specialized structure called the conidiophore. The production of conidiophores is tightly regulated by various regulators, including the central regulatory cascade composed of BrlA-AbaA-WetA, the fungi-specific velvet regulators, upstream regulators, and developmental repressors. In this review, we summarize the findings of a series of recent studies related to asexual development in A. flavus and provide insights for a better understanding of other fungal species in the section Flavi.
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Affiliation(s)
- He-Jin Cho
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Sung-Hun Son
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Wanping Chen
- Department of Molecular Microbiology and Genetics, University of Göttingen, 37077 Göttingen, Germany
| | - Ye-Eun Son
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Inhyung Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
- Department of Systems Biotechnology, Konkuk University, Seoul 05029, Korea
| | - Hee-Soo Park
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
- Department of Integrative Biology, Kyungpook National University, Daegu 41566, Korea
- Correspondence: ; Tel.: +82-53-950-5751
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Qin L, Yang L, Zhao J, Zeng W, Su M, Wang S, Yuan J. GTPase Rac Regulates Conidiation, AFB1 Production and Stress Response in Pathogenic Fungus Aspergillus flavus. Toxins (Basel) 2022; 14:toxins14090581. [PMID: 36136519 PMCID: PMC9503438 DOI: 10.3390/toxins14090581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/14/2022] [Accepted: 08/18/2022] [Indexed: 11/16/2022] Open
Abstract
As a member of the Rho family, Rac plays important roles in many species, including proliferation, differentiation, apoptosis, DNA damage responses, metabolism, angiogenesis, and immunosuppression. In this study, by constructing Rac-deleted mutants in Aspergillus flavus, it was found that the deletion of Rac gene led to the decline of growth and development, conidia production, AFB1 toxin synthesis, and seed infection ability of A. flavus. The deletion of Rac gene also caused the disappearance of A. flavus sclerotium, indicating that Rac is required for sclerotium formation in A. flavus. The sensitivity of Rac-deficient strains responding to cell wall stress and osmotic pressure stress increased when compared to A.flavus WT. The Western blot result showed that mitogen-activated serine/threonine-protein kinase Slt2 and mitogen-activated protein kinase Hog1 proteins were no longer phosphorylated in Rac-deficient strains of A. flavus, showing that Rac may be used as a molecular switch to control the Slt2-MAPK cascade pathway and regulate the osmotic Hog-MAPK cascade pathway in A. flavus in response to external stress. Altogether, these results indicated that Rac was involved in regulating the growth and development, conidia formation and AFB1 synthesis, and response to cell wall stress and osmotic pressure stress in A. flavus.
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Papp V, Dai YC. What is the correct scientific name for “Fuling” medicinal mushroom? Mycology 2022; 13:207-211. [PMID: 35938080 PMCID: PMC9354628 DOI: 10.1080/21501203.2022.2089755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In recent years, the scientific names of many cultivated and well-known medicinal fungal species have been changed. However, the results of taxonomic and nomenclature works on these economically important fungi are often overlooked or ignored in applied researches. The incorrect use of scientific names may cause uncertainty in research and in the global medicinal mushroom market. In this paper, we briefly review the current taxonomy and nomenclature of “Fuling” medicinal mushroom and make a proposal for biochemists, pharmacists and businessmen on the correct use of scientific names related to this species. Based on the recent taxonomic results and nomenclatural proposals, the use of the names Wolfiporia extensa, W. cocos and especially Poria cocos for the “Fuling” mushroom are incorrect and misleading; therefore, the acceptance of the names Pachyma hoelen or Wolfiporia hoelen is recommended.
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Affiliation(s)
- Viktor Papp
- Department of Botany, Hungarian University of Agriculture and Life Sciences, Budapest, Hungary
| | - Yu-Cheng Dai
- Institute of Microbiology, School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
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