Major impacts on the primary metabolism of the plant pathogen Cryphonectria parasitica by the virulence-attenuating virus CHV1-EP713
Major impacts on the primary metabolism of the plant pathogen Cryphonectria parasitica by the virulence-attenuating virus CHV1-EP713
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DOI：
10.1099/mic.0.029033-0
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发表时间：
2009-12-01
期刊：
影响因子：
2.8
通讯作者：
Li, Zhong
中科院分区：
文献类型：
--
作者：
Dawe, Angus L.;Van Voorhies, Wayne A.;Li, Zhong
栗疫病菌（Cryphonectria parasitica）是栗疫病菌，可被贫病毒科（Hypoviridae）的毒力衰减真菌病毒感染。以前的研究已经导致了这样的假设，即低病毒感染的表型部分是由于病毒感染引起的代谢变化。为了研究这一点，我们测量了C。寄生菌菌落在固体培养基上生长。这些实验支持了在液体培养物中进行的其他真菌物种的历史观察，即代谢率随着菌丝体的年龄和分化而稳步下降。低病毒感染增加代谢率在最年轻的菌丝体，但随后的下降也观察到菌丝老化。通过测量CO（2）的产生和O2的消耗，我们还观察到受感染和未受感染的菌丝体由于老化而在碳水化合物代谢中发生的变化。在殖民地外围的菌丝体广泛地利用发酵途径，然后过渡到有氧碳水化合物代谢，最后在内部区域进行脂质代谢，尽管剩余的葡萄糖丰富。然而，低病毒影响了这些变化的程度，感染的菌丝体显然无法利用脂质相关的代谢途径，导致葡萄糖消耗增加。最后，我们使用代谢谱来确定野生型和低病毒感染的菌丝体中初级代谢物积累的变化，发现检测到的164种代谢物中约有三分之一受到影响。这些结果与生理测量的预期结果一致，与脂质和碳水化合物代谢相关的化合物出现显著变化。此外，我们观察到的多胺亚精胺在hypovirus的存在下的积累增加。多胺参与哺乳动物系统的抗病毒反应，因此这可能表明真菌中的一种新的抗病毒反应机制。
Cryphonectria parasitica, the chestnut blight fungus, can be infected by virulence-attenuating mycoviruses of the family Hypoviridae. Previous studies have led to the hypothesis that the hypovirus-infected phenotype is partly due to metabolic changes induced by the viral infection. To investigate this, we measured the metabolic rate and respiration of C. parasitica colonies grown on solid medium. These experiments supported historical observations of other fungal species done in liquid cultures that the metabolic rate steadily declines with age and differentiation of the mycelium. Hypovirus infection increased metabolic rate in the youngest mycelium, but a subsequent decline was also observed as the mycelium aged. By measuring both CO(2) production and 02 consumption, we also observed that changes occur in carbohydrate metabolism as a result of ageing in both infected and uninfected mycelium. Mycelium on the periphery of the colony exploited fermentation pathways extensively, before transitioning to aerobic carbohydrate metabolism and finally lipid metabolism in the interior regions, despite abundant remaining glucose. However, the hypovirus affected the extent of these changes, with infected mycelium apparently unable to utilize lipid-related metabolic pathways, leading to an increased depletion of glucose. Finally, we used metabolic profiling to determine the changes in accumulation of primary metabolites in wild-type and hypovirus-infected mycelium and found that approximately one-third of the 164 detected metabolites were affected. These results are consistent with those expected from the physiological measurements, with significant alterations noted for compounds related to lipid and carbohydrate metabolism. Additionally, we observed an increase in the accumulation of the polyamine spermidine in the presence of hypovirus. Polyamines have been implicated in antiviral responses of mammalian systems; therefore this may suggest a novel antiviral response mechanism in fungi.