Author
CHENG, WANLI - Huazhong University Of Science And Technology | |
CHENG, JINGYAN - Huazhong University Of Science And Technology | |
NIE, QIYU - Huazhong University Of Science And Technology | |
HUANG, DIAN - Huazhong University Of Science And Technology | |
YU, CHEN - Huazhong University Of Science And Technology | |
ZHENG, LONGYU - Huazhong University Of Science And Technology | |
CAI, MINMIN - Huazhong University Of Science And Technology | |
YU, ZINIU - Huazhong University Of Science And Technology | |
ZHANG, JIBIN - Huazhong University Of Science And Technology | |
Thomashow, Linda | |
Weller, David |
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/15/2017 Publication Date: 11/24/2017 Citation: Cheng, W., Cheng, J., Nie, Q., Huang, D., Yu, C., Zheng, L., Cai, M., Yu, Z., Zhang, J., Thomashow, L.S., Weller, D.M. 2017. Volatile organic compounds from Paenibacillus polymyxa KM2501-1 control Meloidogyne incognita by multiple strategies. Scientific Reports. 7:16213. Interpretive Summary: Plant-parasitic nematodes cause serious crop losses worldwide. Treatment of one of the most important plant parasitic nematodes, Meloidogyne incognita, with a new bacterial biological control agent, Paenibacillus polymyxa KM2501-1, killed 88% of the nematodes in the laboratory and reduced symptoms on tomato by up to 83% under greenhouse conditions. This study focused on factors produced by the bacteria that were responsible for killing the nematodes. Eleven volatile organic compounds were isolated and identified, of which 8 killed nematodes upon contact. Six acted as fumigants, killing nematodes from a distance, and 7 attracted the nematodes; two of these attractants also killed the nematodes. Two compounds, as well as the bacteria themselves, destroyed the integrity of the internal organs of the nematode. Collectively the results indicate that the volatile compounds produced by the bacteria act through diverse mechanisms to control this important nematode. Moreover, volatile compounds that act as both as an attractant and as a killing agent exhibit a novel mechanism that extends our understanding of the strategies exploited by biocontrol agents that kill nematodes. Technical Abstract: Plant-parasitic nematodes (PPNs) cause serious crop losses worldwide. Treatment of the PPN Meloidogyne incognita with the biological control agent Paenibacillus polymyxa KM2501-1 resulted in a mortality of 88% in vitro and reduced symptoms on tomato by up to 83% under greenhouse conditions. In this study, we investigated the nematicidal factors and the modes and mechanisms of action involved in nematode control by KM2501-1. We isolated 11 volatile organic compounds (VOCs) from strain KM2501-1, of which 8 had contact nematicidal activity, 6 had fumigant activity, and 7 acted as stable chemotactic agents to M. incognita. The VOCs provided a comprehensive strategy against PPNs that included “honey-trap,” fumigant, attractant and repellent modes. Furfural acetone and 2-decanol functioned as “honey-traps,” attracting M. incognita and then killing it by contact or fumigation. Two other VOCs, 2-nonanone and 2-decanone, as well as strain KM2501-1 itself, destroyed the integrity of the intestine and pharynx. Collectively our results indicate that VOCs produced by P. polymyxa KM2501-1 act through diverse mechanisms to control M. incognita. Moreover, the novel honey-trap mode of VOC–nematode interaction revealed in this study extends our understanding of the strategies exploited by nematicidal biocontrol agents. |