Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824, USA.
Toxins (Basel). 2013 Apr 18;5(4):683-702. doi: 10.3390/toxins5040683.
There is extensive and unequivocal evidence that secondary metabolism in filamentous fungi and plants is associated with oxidative stress. In support of this idea, transcription factors related to oxidative stress response in yeast, plants, and fungi have been shown to participate in controlling secondary metabolism. Aflatoxin biosynthesis, one model of secondary metabolism, has been demonstrated to be triggered and intensified by reactive oxygen species buildup. An oxidative stress-related bZIP transcription factor AtfB is a key player in coordinate expression of antioxidant genes and genes involved in aflatoxin biosynthesis. Recent findings from our laboratory provide strong support for a regulatory network comprised of at least four transcription factors that bind in a highly coordinated and timely manner to promoters of the target genes and regulate their expression. In this review, we will focus on transcription factors involved in co-regulation of aflatoxin biosynthesis with oxidative stress response in aspergilli, and we will discuss the relationship of known oxidative stress-associated transcription factors and secondary metabolism in other organisms. We will also talk about transcription factors that are involved in oxidative stress response, but have not yet been demonstrated to be affiliated with secondary metabolism. The data support the notion that secondary metabolism provides a secondary line of defense in cellular response to oxidative stress.
有大量确凿的证据表明，丝状真菌和植物中的次生代谢与氧化应激有关。支持这一观点的是，已证实与酵母、植物和真菌中氧化应激反应相关的转录因子参与控制次生代谢。作为次生代谢的一个模型，黄曲霉毒素生物合成已被证明是由活性氧积累引发和加剧的。一个与氧化应激相关的 bZIP 转录因子 AtfB 是协调表达抗氧化基因和参与黄曲霉毒素生物合成基因的关键因子。我们实验室的最新发现为一个调控网络提供了强有力的支持，该网络至少包含四个转录因子，它们以高度协调和及时的方式结合到靶基因的启动子上，并调节它们的表达。在这篇综述中，我们将重点讨论与曲霉中黄曲霉毒素生物合成与氧化应激反应的共调控有关的转录因子，并讨论已知与氧化应激相关的转录因子与其他生物体中的次生代谢之间的关系。我们还将讨论涉及氧化应激反应但尚未证明与次生代谢有关的转录因子。这些数据支持这样一种观点，即次生代谢为细胞对氧化应激的反应提供了第二道防线。
