Ornithine Decarboxylase-Mediated Production of Putrescine Influences Ganoderic Acid Biosynthesis by Regulating Reactive Oxygen Species in Ganoderma lucidum
Ornithine Decarboxylase-Mediated Production of Putrescine Influences Ganoderic Acid Biosynthesis by Regulating Reactive Oxygen Species in Ganoderma lucidum
复制标题
鸟氨酸脱羧酶介导的腐胺生产通过调节灵芝中的活性氧影响灵芝酸生物合成
DOI：
10.1128/aem.01289-17
复制
发表时间：
2017-10-01
影响因子：
4.4
通讯作者：
Zhao, Ming-Wen
中科院分区：
文献类型：
--
作者：
Wu, Chen-Gao;Tian, Jia-Long;Zhao, Ming-Wen
腐胺是一种重要的多胺，参与多种应激反应。鸟氨酸脱羧酶(ODC)是催化腐胺生物合成的关键酶。从灵芝中克隆了ODC编码基因的同源序列。在ODC沉默的菌株中，ODC基因的转录水平和腐胺含量显著降低。ODC沉默的菌株对氧化应激更敏感。在ODC沉默的菌株中，灵芝酸的含量增加了大约43%到46%。添加外源腐胺后，灵芝酸的含量可以恢复。此外，在ODC沉默的菌株中，活性氧(ROS)的含量显著增加约1.3倍。添加外源腐胺后，ROS含量显著降低。通过基因转录水平和四种主要抗氧化酶活性的测定，进一步探讨腐胺对细胞内ROS水平的影响。进一步的研究表明，ODC介导的腐胺合成对ROS的影响可能是影响灵芝酸生物合成的一个因素。本研究报道了腐胺在大型担子菌中的作用，为进一步研究腐胺在微生物中的生理功能提供了基础。重要性众所周知，ODC和ODC介导的腐胺的产生在抵抗各种环境胁迫中发挥着重要作用，但关于腐胺对微生物，特别是真菌中次生代谢的影响机制的报道很少。灵芝正逐渐成为研究环境调节和新陈代谢的模式生物。在本研究中，我们克隆了灵芝ODC基因的同源基因。我们发现，在ODC沉默的菌株中，ODC基因的转录水平和腐胺含量显著降低。在ODC沉默的菌株中，灵芝酸含量显著增加。进一步的研究表明，ODC介导的腐胺合成对ROS的影响可能是影响灵芝酸生物合成的一个因素。本研究报道了腐胺在大型担子菌中的作用，为进一步研究腐胺在微生物中的生理功能提供了基础。
ABSTRACT Putrescine is an important polyamine that participates in a variety of stress responses. Ornithine decarboxylase (ODC) is a key enzyme that catalyzes the biosynthesis of putrescine. A homolog of the gene encoding ODC was cloned from Ganoderma lucidum. In the ODC-silenced strains, the transcript levels of the ODC gene and the putrescine content were significantly decreased. The ODC-silenced strains were more sensitive to oxidative stress. The content of ganoderic acid was increased by approximately 43 to 46% in the ODC-silenced strains. The content of ganoderic acid could be recovered after the addition of exogenous putrescine. Additionally, the content of reactive oxygen species (ROS) was significantly increased by approximately 1.3-fold in the ODC-silenced strains. The ROS content was significantly reduced after the addition of exogenous putrescine. The gene transcript levels and the activities of four major antioxidant enzymes were measured to further explore the effect of putrescine on the intracellular ROS levels. Further studies showed that the effect of the ODC-mediated production of putrescine on ROS might be a factor influencing the biosynthesis of ganoderic acid. Our study reports the role of putrescine in large basidiomycetes, providing a basis for future studies of the physiological functions of putrescine in microbes. IMPORTANCE It is well known that ODC and the ODC-mediated production of putrescine play an important role in resisting various environmental stresses, but there are few reports regarding the mechanisms underlying the effect of putrescine on secondary metabolism in microorganisms, particularly in fungi. G. lucidum is gradually becoming a model organism for studying environmental regulation and metabolism. In this study, a homolog of the gene encoding ODC was cloned in Ganoderma lucidum. We found that the transcript level of the ODC gene and the content of putrescine were significantly decreased in the ODC-silenced strains. The content of ganoderic acid was significantly increased in the ODC-silenced strains. Further studies showed that the effect of the ODC-mediated production of putrescine on ROS might be a factor influencing the biosynthesis of ganoderic acid. Our study reports the role of putrescine in large basidiomycetes, providing a basis for future studies of the physiological functions of putrescine in microbes.