《环境昆虫学报》

日本黑松是我国胶东半岛沿海防护林主要树种之一，而入侵物种长林小蠹的大面积危害，严重影响了胶东半岛的海防林质量。为了解长林小蠹侵染对黑松根系代谢物和挥发性物质的变化，本研究采集健康、侵染初期和后期的黑松根际土壤，使用静态顶空吸附方法采集健康、侵染初期、后期及机械损伤的根系挥发性物质。分别采用超高效液相色谱-质谱联用仪（UPLC-MS）和气相色谱-质谱联用仪（GC-MS）进行根际代谢物和根系挥发性物质的分析。主要结果如下：根际共检测出1 183种代谢物，除其他以外脂质及其衍生物占比最大（25.87%）。不同危害组的黑松根际代谢物有一定分离，初侵染黑松与健康黑松相比包括马兜铃酮、诺卡酮、Ubiquinone Q2和磷脂酰丝氨酸在内共有21种显著差异代谢物（VIP>1，|Log2FC|>1，P<0.05），与侵染后期相比共24种显著差异代谢物，可溶性糖半乳糖、葡萄糖和甘露糖含量随长林小蠹侵染程度的增加先下降后上升。黑松根系共检测出30种挥发物，其中健康黑松24种，虫害黑松29种，机械损伤黑松23种，(1R)-(+)-α-蒎烯相对含量最大，在健康组（H）、侵染初期组（Y）、侵染后期组（D）和机械损伤组（J）这四组黑松中分别占48.21%、56.88%、62.77%、58.06%。(1R)-(+)-α-蒎烯、D-柠檬烯、(-)-β-蒎烯、莰烯和α-水芹烯的相对含量在危害初期呈上升趋势，而在后期，仅（1R)-(+)-α-蒎烯和莰烯继续上升，且莰烯作为虫害特异性挥发物在机械损伤后含量下降。D-樟脑（天然）、龙脑、4-乙烯基-1,2-二甲基苯、葑醇、α-松油醇和1,8-桉树脑仅在长林小蠹危害组中发现，健康组和机械损伤组均未检测到。结果表明，黑松在长林小蠹侵染初期通过增加马兜铃酮、诺卡酮、(1R)-(+)-α-蒎烯、D-柠檬烯、莰烯等抗逆成分和减少可溶性糖含量抵御长林小蠹的侵染；后期濒死黑松表现为抗逆成分显著降低而可溶性糖含量上升。本研究表明，可利用诺卡酮开发天然衍生杀虫剂，利用莰烯开发新型植物源引诱剂，为进一步研究长林小蠹侵染机制和绿色高效的虫害防控技术提供理论基础。

英文摘要:

Pinus thunbergii is one of the main species in the coastal protection forests of the Jiaodong Peninsula, China. The large-scale damage caused by the invasive species Hylurgus ligniperda has seriously affected the quality of the coastal protection forests in the Jiaodong Peninsula. This study aimed to understand the changes in metabolites and volatiles in the root systems of P. thunbergii infested by H. ligniperda. Rhizosphere soils of P. thunbergii under healthy, early-stage infestation, and late-stage infestation states were collected. Additionally, volatiles of root system were collected from healthy P. thunbergii, those in the early and late stages of H. ligniperda infestation, and those with mechanical damage using the static headspace adsorption. Ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS) and gas chromatography-mass spectrometry (GC-MS) were used to analyze rhizosphere metabolites and root volatiles, respectively. The main results are as follows: a total of 1 183 metabolites were detected in the rhizosphere of P. thunbergii, among which lipids and their derivatives accounted for the largest proportion (25.87%). Rhizosphere metabolites differed among groups at different infestation stages. Compared with healthy P. thunbergii, those at the early-stage infestation showed 21 significantly differential metabolites (VIP > 1, |Log2FC| > 1, P < 0.05), including aristolone, nootkatone, ubiquinone Q2, and phosphatidylserine. In comparison with the late infestation stage, there were 24 significantly differential metabolites. The contents of soluble sugars (such as galactose, glucose, and mannose) initially decreased and then increased with the severity of H. ligniperda infestation. Thirty volatile compounds were detected in the roots of P. thunbergii, with 24, 29, and 23 volatile compounds identified in healthy roots, pest-infested roots and mechanically damaged roots, respectively. The relative content of (1R)-(+)-α-pinene was the highest, accounting for 48.21%, 56.88%, 62.77% and 58.06% in the healthy (H), early-infested (Y), late-infested (D) and mechanically damaged (J) groups, respectively. The relative contents of (1R)-(+)-α-pinene, D-limonene, (-)-β-pinene, camphene, and α-phellandrene increased in the early stage of pest infestation. However, only (1R)-(+)-α-pinene and camphene showed a continuous increase in the late stage. Additionally, camphene, as a pest-specific volatiles, decreased after mechanical damage. D-camphor (natural), borneol, 4-etheny-1,2-dimethylbenzene, fenchol, α-terpineol, and 1,8-eucalyptol were detected only in the group infested by H. ligniperda, but not in the healthy group or the mechanically damaged group. The results showed that at the early stage of H. ligniperda infestation, P. thunbergii could resist the infestation by increasing stress-resistant components such as aristolone, nootkatone, (1R)-(+)-α-pinene, D-limonene and camphene, while decreasing soluble sugar content. At the later stage of infestation, dying pines reduced stress-resistant components and increased soluble sugar content. This study revealed that nootkatone can be exploited for the development of natural derivative insecticides, while camphene holds potential for the creation of novel plant-derived attractants. These findings lay a theoretical foundation for in-depth investigations into infestation mechanisms and the development of green, efficient pest control technologies.

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