Interspecific variation in spruce constitutive and induced defenses in response to a bark beetle fungal symbiont provides insight into traits associated with resistance.
Interspecific variation in spruce constitutive and induced defenses in response to a bark beetle fungal symbiont provides insight into traits associated with resistance.
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云杉对树皮甲虫真菌共生体的本构防御和诱导防御的种间变异提供了对与抗性相关的性状的深入了解。
DOI：
10.1093/treephys/tpaa170
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发表时间：
2021
期刊：
影响因子：
4
通讯作者：
Javier E. Mercado
中科院分区：
文献类型：
--
作者：
D. Ott;T. S. Davis;Javier E. Mercado
不同树种防御特性的差异可以预测为什么一些针叶树易受小蠹真菌复合体的影响，而另一些则不然。一种共生真菌（Leptographium abietinum）与树木杀死树皮甲虫（Dendroctonus rufipennis）是植物病原宿主树木，并可能加速树木衰退，在定殖过程中的甲虫，但成熟的树木防御反应的真菌还没有实验研究。为了验证云杉抗性种间变异是由防御性状解释的这一假设，我们比较了云杉的组成型（树皮厚度和组成树脂导管）和诱导防御（树脂流动，单萜成分，浓度，韧皮部损伤的形成，和创伤树脂导管）之间的两个同域云杉：恩格曼云杉（Piceaengelmannii，一种敏感宿主）和蓝云杉（P. pungens，一种抗性宿主）对真菌接种的响应。得出了四个主要结论：（2）两种云杉物种响应于接种诱导单萜，但蓝云杉具有较高的组成型单萜水平，更快速地诱导单萜，并且在与云杉甲虫攻击持续时间一致的一段时间内诱导较高的浓度;（3）恩格曼云杉和蓝云杉对真菌诱导的单萜类化合物的表达不同，蓝云杉对α-蒎烯、萜品油烯和γ-萜品烯的表达上调，而恩格曼云杉对3-<$烯和芳樟醇的表达上调;（4）蓝云杉比安格曼云杉具有更高的组成型树脂道频率，在年生长增量中产生更多的创伤性树脂道，尽管恩格曼云杉在无菌创伤或真菌接种后产生更多的树脂。这些发现表明，较高的树脂道密度和单萜浓度，以及快速诱导特定的单萜响应L。冷杉接种，是与宿主抗云杉甲虫定殖相关的表型性状。
Differences in defensive traits of tree species may predict why some conifers are susceptible to bark beetle-fungal complexes and others are not. A symbiotic fungus (Leptographium abietinum) associated with the tree-killing bark beetle (Dendroctonus rufipennis) is phytopathogenic to host trees and may hasten tree decline during colonization by beetles, but defense responses of mature trees to the fungus have not been experimentally examined. To test the hypothesis that interspecific variation in spruce resistance is explained by defense traits we compared constitutive (bark thickness and constitutive resin ducts) and induced defenses (resin flow, monoterpene composition, concentration, phloem lesion formation, and traumatic resin ducts) between two sympatric spruces: Engelmann spruce (Picea engelmannii, a susceptible host) and blue spruce (P. pungens, a resistant host) in response to fungal inoculation. Four central findings emerged: (1) blue spruce has thicker outer bark and thinner phloem than Engelmann spruce, which may restrict fungal access to phloem and result in less beetle-available resource overall; (2) both spruce species induce monoterpenes in response to inoculation but blue spruce has higher constitutive monoterpene levels, induces monoterpenes more rapidly, and induces higher concentrations over a period of time consistent with spruce beetle attack duration; (3) Engelmann and blue spruce differed in the monoterpenes they upregulated in response to fungal inoculation: blue spruce upregulated α-pinene, terpinolene, and γ-terpinene, but Engelmann spruce upregulated 3-carene and linalool; and (4) blue spruce has a higher frequency of constitutive resin ducts and produces more traumatic resin ducts in annual growth increments than Engelmann spruce, though Engelmann spruce produces more resin following aseptic wounding or fungal inoculation. These findings suggest that higher constitutive resin duct densities and monoterpene concentrations, as well as the ability to rapidly induce specific monoterpenes in response to L. abietinum inoculation, are phenotypic traits associated with hosts resistant to spruce beetle colonization.
影响因子：
20.5
作者：
Erb, Matthias;Meldau, Stefan;Howe, Gregg A.
通讯作者：
Howe, Gregg A.