Antifungal Mechanism of Metabolites from Newly Isolated _Streptomyces_ sp. Y1-14 against Banana Fusarium Witt Disease Using Metabolomics  
[PERSON]  
1 College of Horticulture/College of Tropical Crops, Hainan University, Haikou 570228, China  
2 Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China  
3 College of Horticulture, China Agricultural University, Beijing 100083, China  
4 College of Horticulture and Forestry Sciences/Faculty of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China  
5 Correspondence: [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (W.W.)  
Qifeng Cheng  
1 College of Horticulture/College of Tropical Crops, Hainan University, Haikou 570228, China  
2 Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China  
3 College of Horticulture, China Agricultural University, Beijing 100083, China  
4 College of Horticulture and Forestry Sciences/Faculty of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China  
5 Correspondence: [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (W.W.)  
[PERSON]  
1 College of Horticulture/College of Tropical Crops, Hainan University, Haikou 570228, China  
2 Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China  
3 College of Horticulture, China Agricultural University, Beijing 100083, China  
4 College of Horticulture and Forestry Sciences/Faculty of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
Functional microbes are an alternative to minimize the effects of chemical agents on environment pollution and human health. They become an important resource for biological control of Foc TR4 [7]. For example, _Trichoderma_ strains can significantly inhibit the spread of banana wilt disease [8]. _Bacillus subtilis_ R31 and TR21 showed beneficial effects on the control of Foc TR4 [9]. A growth promotion of _Burkholderia_ sp. HQB-1 could be a promising biological agent against Foc TR4 [10]. Natural products (NPs) from different microbes have widely applied in medical and agricultural fields [11]. Actinomycetes are ubiquitous in various ecosystem. They produce several bioactive compounds with strong antimicrobial activities [12; 13; 14]. For example, endophytic actinomycetes isolated from tea plants (_Camellia sinensis_) showed strong antagonistic activities against both bacterial and fungal pathogens [15]. Our previous studies also showed that actinomycetes have a great potential to become biocontrol agents for managing banana Fusarium wilt disease [16; 17; 18]. For example, _Streptomyces_ sp. H4 showed a high antifungal activity against Foc TR4 [16]. _Streptomyces_ BITDG-11 obviously reduced the disease index of Foc TR4 on banana plantlets [17]. _Streptomyces_ sp. WHL7 significantly inhibited the growth of pathogens and increased the resistance of banana plantlets to Foc TR4 in the pot experiment [18]. Although some actinomycetes against Foc TR4 were screened, they are rarely used in the field due to their isolation from extreme environments such as oceans. Structural characteristics of distinct microbiomes in the suppressive and conducive soils were detected after Foc TR4 infection [19]. Therefore, the isolation of functional actinomycetes from the suppressive soils is an important way to explore the antagonistic agents. In our study, to screen the biocontrol potential agents for Foc TR4, banana plantation soil without Foc TR4 disease symptoms for ten years was collected. These isolated species were identified by the physiological and biochemical characteristics and molecular method.