Multiple modes of nematode control by volatiles of Pseudomonas putida 1A00316 from Antarctic soil against Meloidogyne incognita

Authors: ZHAI, YILE - Huazhong Agricultural University; SHAO, ZONGZE - State Oceanic Administration; CAI, MINMIN - Huazhong Agricultural University; ZHENG, LONGYU - Huazhong Agricultural University; LI, GUANGYU - State Oceanic Administration; HUANG, DIAN - Huazhong Agricultural University; CHENG, WANLI - Huazhong Agricultural University; Thomashow, Linda; Weller, David; YU, ZINIU - Huazhong Agricultural University; ZHANG, JIBIN - Huazhong Agricultural University

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2018
Publication Date: 2/23/2018
Citation: Zhai, Y., Shao, Z., Cai, M., Zheng, L., Li, G., Huang, D., Cheng, W., Thomashow, L.S., Weller, D.M., Yu, Z., Zhang, J. 2018. Multiple modes of nematode control by volatiles of Pseudomonas putida 1A00316 from Antarctic soil against Meloidogyne incognita. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2018.00253.
DOI: https://doi.org/10.3389/fmicb.2018.00253

Interpretive Summary: Little was known about whether strain Pseudomonas putida 1A00316, an isolate from Antarctic soil, could produce volatile organic compounds (VOCs) and if they had potential for use in biological control against the widespread plant pathogenic root knot nematode Meloidogyne incognita. In this study, VOCs produced by a culture filtrate of Pseudomonas putida 1A00316 were evaluated in the laboratory in three-compartment Petri dishes and 96-well culture plates. Our results showed that M. incognita juvenile nematodes gradually reduced their movement within 24-48 h of incubation and mostly stopped moving after 72 h. Moreover, egg hatching in culture filtrates of strain 1A00316 was much reduced compared to that in sterile distilled water or culture medium. Analysis of the volatiles from P. putida 1A00316 was carried out by solid-phase micro-extraction gas chromatography–mass spectrometry (SPME-GC/MS) identified the compounds dimethyl-disulfide, 1-undecene, 2-nonanone, 2-octanone, (Z)-hexen-1-ol acetate, 2-undecanone and 1-(ethenyloxy)-octadecane. Of these, dimethyl-disulfide, 2-nonanone, 2-octanone, (Z)-hexen-1-ol acetate and 2-undecanone had strong killing activity against M. incognita juveniles by direct-contact in 96-well culture plates, and only 2-undecanone acted as a volatile fumigant. In addition, the 7 VOCs inhibited egg hatching both by direct-contact and by fumigation. All of the 7 VOCs repelled M. incognita J2 juveniles on 2% water agar Petri plates. These results show that VOCs from strain 1A00316 act on different stages in the development of M. incognita via nematicidal, fumigant and repellent activities and have potential for development as biocontrol agents with multiple modes of control of root-knot nematodes

Technical Abstract: Pseudomonas putida 1A00316, isolated from Antarctic soil, showed nematicidal potential for biological control of Meloidogyne incognita (M. incognita); however, little was known about whether strain 1A00316 could produce volatile organic compounds (VOCs) and if they had potential for use in biological control against M. incognita. In this study, VOCs produced by a culture filtrate of Pseudomonas putida 1A00316 were evaluated by in vitro experiments in three-compartment petri dishes and 96-well culture plates. Our results showed that M. incognita juveniles gradually reduced their movement within 24-48 h of incubation with mortality ranging from 6.49 % to 86.19 %, and mostly stopped action after 72 h. Moreover, egg hatching in culture filtrates of strain 1A00316 was much reduced compared to that in sterile distilled water or culture medium. Volatiles from P. putida 1A00316 analysis carried out by solid-phase micro-extraction gas chromatography–mass spectrometry (SPME-GC/MS) included dimethyl-disulfide, 1-undecene, 2-nonanone, 2-octanone, (Z)-hexen-1-ol acetate, 2-undecanone and 1-(ethenyloxy)-octadecane. Of these, dimethyl-disulfide, 2-nonanone, 2-octanone, (Z)-hexen-1-ol acetate and 2-undecanone had strong nematicidal activity against M. incognita J2 larvae by direct-contact in 96-well culture plates, and only 2-undecanone acted as a fumigant. In addition, the 7 VOCs inhibited egg hatching of M. incognita both by direct-contact and by fumigation. All of the 7 VOCs repelled M. incognita J2 juveniles in 2% water agar petri plates. These results show that VOCs from strain 1A00316 act on different stages in the development of M. incognita via nematicidal, fumigant and repellent activities and have potential for development as agents with multiple modes of control of root-knot nematodes