Effects of tree phytochemistry on the interactions among endophloedic fungi associated with the southern pine beetle
Effects of tree phytochemistry on the interactions among endophloedic fungi associated with the southern pine beetle
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DOI：
10.1007/s10886-005-2035-4
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发表时间：
2005-03-01
影响因子：
2.3
通讯作者：
Ayres, MP
中科院分区：
文献类型：
--
作者：
Hofstetter, RW;Mahfouz, JB;Ayres, MP
我们研究了寄主树木和真菌之间的相互作用，这些真菌与一种杀死树木的树皮甲虫有关。我们评估了(1)4种松树对真菌入侵的反应(2)植物次生代谢物对3种一致真菌伴生物初生生长和次生定植的影响。其中两种真菌，虫皮质菌A和蛇皮菌A，是与frontalis的专性共生菌，第三种是一种蓝色真菌O. minus，通常由甲虫和虫螨引入。负o对甲虫幼虫有负向影响，高丰度可影响额天牛种群动态。不同种类的松树在真菌接种后形成的病变大小和次生代谢物的数量有显著差异。然而，感染组织内的单萜组成在不同的治疗中没有显著变化。所有8种代谢物均对O. minus的生长速率产生负影响，只有4-烯丙烯醇、对伞花素和萜烯抑制了真菌的生长。令人惊讶的是，在几种次生代谢物挥发物的存在下，真菌的生长速度增加了。O. minus在竞争中战胜了两种真菌，但次级代谢物的存在稍微改变了结果。在存在优势的针叶树单萜，如α -蒎烯和β -蒎烯的情况下，O. ranaculosunt优于E. sp. A。霉菌的挥发物，特别是e.sp . A，对O.负生长有负面影响。一般来说，特定种类松木的韧皮部植物化学似乎改变了与赤叶松相关的共生和非共生真菌的相对生长和竞争。这些真菌之间相互作用的结果可能对frontalis的种群动态有重要影响。
We examined the interaction between host trees and fungi associated with a tree-killing bark beetle, Dendroctonus frontalis. We evaluated (1) the response of four Pinus species to fungal invasion and (2) the effects of plant secondary metabolites on primary growth of and secondary colonization of three consistent fungal associates. Two of these fungi, Entomocorticium sp. A and Ophiostoma ranaculosum, are obligate mutualists with D.frontalis, and the third associate is a blue-staining fungus, O. minus, that is commonly introduced by beetles and phoretic mites. O. minus negatively affects beetle larvae and in high abundance can impact D. frontalis population dynamics. Size of lesions formed and quantity of secondary metabolites produced in response to fungal inoculations varied significantly among Pinus species. However, monoterpene composition within infected tissue did not significantly vary across treatments. While all eight tested metabolites negatively affected the growth rate of O. minus, only 4-allylanisole, p-cymene, and terpinene reduced the growth of the mycangial fungi. Surprisingly, growth rates of mycangial fungi increased in the presence of several secondary metabolite volatiles. O. minus out-competed both mycangial fungi, but the presence of secondary metabolites altered the outcome slightly. O. ranaculosunt out-performed E. sp. A in the presence of dominant conifer monoterpenes, such as alpha- and beta-pinene. Volatiles from the mycangial fungi, particularly E. sp. A, had a negative effect on O. minus growth. In general, phloem phytochemistry of particular Pinus species appeared to alter the relative growth and competitiveness of mutualistic and non-mutualistic fungi associated with D.frontalis. The outcome of interactions among these fungi likely has important consequences for the population dynamics of D. frontalis.