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Ye S, Zhou S, Ma Y, Yang J, Shi X, Zhang R, Yang Z, Peng D, Ding Z. Biocontrol activity and potential mechanism of Bacillus cereus G5 against Meloidogyne graminicola. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 204:106079. [PMID: 39277392 DOI: 10.1016/j.pestbp.2024.106079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Revised: 07/26/2024] [Accepted: 08/05/2024] [Indexed: 09/17/2024]
Abstract
Root-knot nematodes (Meloidogyne spp.) are highly destructive pests that cause significant yield losses annually. Biological control of nematodes has emerged as a potential alternative in sustainable agriculture. In this study, we originally isolated Bacillus cereus G5 from the rhizosphere soil of rice (Oryza sativa). Treatment with the fermentation supernatant of G5 in vitro demonstrated high toxicity to second-stage juveniles (J2) of Meloidogyne graminicola and remarkably inhibited egg hatching. Moreover, G5 steadily colonized rhizosphere soil and rice seedlings, and exhibited excellent biocontrol efficacy against M. graminicola under greenhouse conditions. Notably, the volatile organic compounds (VOCs) produced by G5 displayed high fumigant activity against M. graminicola. The G5 VOCs efficiently reduced the gall index and nematode population in rice roots, while also promoting rice growth in double-layered pot tests. Additionally, the expression of defense genes involved in the salicylic acid (OsNPR1, OsWRKY45, OsPAL1), jasmonic acid (OsJaMYB, OsAOS2) and ethylene (OsACS1) signalling pathways was significantly upregulated in rice seedlings treated with G5 VOCs. This suggests that G5 VOCs contribute to eliciting plant defense responses. Furthermore, we identified 14 major VOCs produced by G5 using solid-phase micro-extraction gas chromatography and mass spectrometry (SPEM-GC-MS). Notably, allomatrine, morantel, 1-octen-3-ol and 3-methyl-2-butanol displayed strong contact nematicidal activity. Among these, only 1-octen-3-ol demonstrated fumigant activity against J2s of M. graminicola, with an LC50 value of 758.95 mg/L at 24 h. Overall, these results indicated that the B. cereus G5 and its synthetic VOCs possess high potential as biocontrol agents for managing root-knot nematodes.
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Affiliation(s)
- Shan Ye
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan 410128, China; Hunan Provincial Engineering & Technology Research Center for Biopesticide and Formulation Processing, Changsha, Hunan 410128, China
| | - Siyu Zhou
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan 410128, China
| | - Yihang Ma
- Hunan Institute of Metrology and Test, Changsha, Hunan 410005, China
| | - Jiahao Yang
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan 410128, China
| | - Xuqi Shi
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan 410128, China
| | - Ruoyu Zhang
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan 410128, China
| | - Zhuhong Yang
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan 410128, China; Hunan Provincial Engineering & Technology Research Center for Biopesticide and Formulation Processing, Changsha, Hunan 410128, China
| | - Deliang Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zhong Ding
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan 410128, China; Hunan Provincial Engineering & Technology Research Center for Biopesticide and Formulation Processing, Changsha, Hunan 410128, China.
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Chen L, Wang Y, Zhu L, Min Y, Tian Y, Gong Y, Liu X. 3-(Methylthio)Propionic Acid from Bacillus thuringiensis Berliner Exhibits High Nematicidal Activity against the Root Knot Nematode Meloidogyne incognita (Kofoid and White) Chitwood. Int J Mol Sci 2024; 25:1708. [PMID: 38338986 PMCID: PMC10855422 DOI: 10.3390/ijms25031708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/22/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024] Open
Abstract
Root knot nematodes cause serious damage to global agricultural production annually. Given that traditional chemical fumigant nematicides are harmful to non-target organisms and the environment, the development of biocontrol strategies has attracted significant attention in recent years. In this study, it was found that the Bacillus thuringiensis Berliner strain NBIN-863 exhibits strong fumigant nematicidal activity and has a high attraction effect on Meloidogyne incognita (Kofoid and White) Chitwood. Four volatile organic compounds (VOCs) produced by NBIN-863 were identified using solid-phase microextraction and gas chromatography-mass spectrometry. The nematicidal activity of four VOCs, namely, N-methylformamide, propenamide, 3-(methylthio)propionic acid, and phenylmalonic acid, was detected. Among these compounds, 3-(methylthio)propionic acid exhibited the highest direct contact nematicidal activity against M. incognita, with an LC50 value of 6.27 μg/mL at 24 h. In the fumigant bioassay, the mortality rate of M. incognita treated with 1 mg/mL of 3-(methylthio)propionic acid for 24 h increased to 69.93%. Furthermore, 3-(methylthio)propionic acid also exhibited an inhibitory effect on the egg-hatching of M. incognita. Using chemotaxis assays, it was determined that 3-(methylthio)propionic acid was highly attractive to M. incognita. In pot experiments, the application of 3-(methylthio)propionic acid resulted in a reduction in gall numbers, decreasing the number of galls per gram of tomato root from 97.58 to 6.97. Additionally, the root length and plant height of the treated plants showed significant increases in comparison with the control group. The current study suggests that 3-(methylthio)propionic acid is a novel nematicidal virulence factor of B. thuringiensis. Our research provides evidence for the potential use of NBIN-863 or its VOCs in biocontrol against root knot nematodes.
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Affiliation(s)
| | | | | | | | | | | | - Xiaoyan Liu
- National Biopesticide Engineering Technology Research Centre, Hubei Biopesticide Engineering Research Centre, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (L.C.); (Y.W.); (L.Z.); (Y.M.); (Y.T.); (Y.G.)
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