Qiu Rui, Qu Dong, Trengove Robert, Agarwal Manjree, Hardy Giles E St J, Ren Yonglin
College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA, 6150 Australia; Cooperative Research Centre for National Plant Biosecurity, Bruce, ACT 2617.
College of Natural Resources and Environment, Northwest A&F University, Yangling.
Plant Dis. 2014 Aug;98(8):1099-1105. doi: 10.1094/PDIS-01-14-0049-RE.
Volatile organic compounds (VOCs) from Phytophthora cinnamomi-infected lupin seedlings were collected by headspace solid-phase microextraction (HS-SPME). The sampling was done 28 to 44, 52 to 68, and 76 to 92 h after inoculation (HAI). The HS-SPME samples were analyzed by gas chromatography-flame ionization detector (GC-FID) to assess the differences in volatile compounds between the P. cinnamomi-infected lupin seedlings and the control. Three specific peaks were identified after 52 to 68 h with the infected lupin seedlings, at which time there were no visible aboveground symptoms of infection. Subsequently, the VOCs of five different substrates (V8A, PDA, lupin seedlings, soil, and soil + lupin seedlings) infected with P. cinnamomi and the corresponding controls were analyzed by gas chromatography-mass spectrometry (GC/MS). A total of 87 VOCs were identified. Of these, the five most abundant that were unique to all five inoculated substrates included: 4-ethyl-2-methoxyphenol, 4-ethylphenol, butyrolactone, phenylethyl alcohol, and 3-hydroxy-2-butanone. Therefore, these metabolites can be used as markers for the identification of P. cinnamomi in different growing environments. Some VOCs were specific to a particular substrate; for example, 2,4,6-rrimethyl-heptanes, dl-6-methyl-5-hepten-2-ol, dimethyl trisulfide, 6,10-dimethyl- 5,9-undecadien-2-ol, and 2-methoxy-4-vinylphenol were specific to P. cinnamomi + V8A; heptanes and 5-methyl-3-heptaneone were specific to P. cinnamomi + PDA; 3-methyl-1-butanol, ethyl acetate, 2-methyl-propanoic acid, ethyl ester, and ethyl ester 2-methyl-butanoic acid were specific to P. cinnamomi-inoculated lupin seedlings; and benzyl alcohol and 4-ethyl-1, 2-dimethoxybenzene were only detected in the headspace of inoculated soil + lupin seedlings. Results from this investigation have multiple impacts as the volatile organic profiles produced by the pathogen can be utilized as an early warning system to detect the pathogen from contaminated field soil samples. Data from this investigation have also illuminated potential metabolic pathways utilized by the oomycete during infection which may serve as potential targets for the development of specific control strategies.
采用顶空固相微萃取（HS-SPME）收集来自感染了樟疫霉的羽扇豆幼苗的挥发性有机化合物（VOCs）。采样在接种后28至44小时、52至68小时以及76至92小时进行。通过气相色谱 - 火焰离子化检测器（GC-FID）对HS-SPME样品进行分析，以评估感染樟疫霉的羽扇豆幼苗与对照之间挥发性化合物的差异。在感染的羽扇豆幼苗接种后52至68小时鉴定出三个特定峰，此时地上部分没有明显的感染症状。随后，采用气相色谱 - 质谱联用仪（GC/MS）分析了感染樟疫霉的五种不同基质（V8A、PDA、羽扇豆幼苗、土壤以及土壤 + 羽扇豆幼苗）及其相应对照的VOCs。共鉴定出87种VOCs。其中，在所有五种接种基质中都特有的含量最丰富的五种物质包括：4-乙基-2-甲氧基苯酚、4-乙基苯酚、丁内酯、苯乙醇和3-羟基-2-丁酮。因此，这些代谢产物可作为在不同生长环境中鉴定樟疫霉的标志物。一些VOCs对特定基质具有特异性；例如，2,4,6-三甲基庚烷、dl-6-甲基-5-庚烯-2-醇、二甲基三硫醚、6,10-二甲基-5,9-十一碳二烯-2-醇和2-甲氧基-4-乙烯基苯酚对樟疫霉 + V8A具有特异性；庚烷和5-甲基-3-庚酮对樟疫霉 + PDA具有特异性；3-甲基-1-丁醇、乙酸乙酯、2-甲基丙酸乙酯和2-甲基丁酸乙酯对接种了樟疫霉的羽扇豆幼苗具有特异性；而苯甲醇和4-乙基-1,2-二甲氧基苯仅在接种的土壤 + 羽扇豆幼苗的顶空中检测到。本研究结果具有多方面的影响，因为病原体产生的挥发性有机化合物谱可作为一种预警系统，用于从受污染的田间土壤样品中检测病原体。本研究的数据还揭示了卵菌在感染过程中利用的潜在代谢途径，这可能成为开发特定控制策略的潜在靶点。
