Department of Biological Sciences, Columbia University, New York, New York, USA.
Antioxid Redox Signal. 2012 Apr 1;16(7):658-67. doi: 10.1089/ars.2011.4249. Epub 2011 Nov 2.
Plant biologists and microbiologists have long discussed and debated the physiological roles of so-called "redox-active metabolites." These are natural products with unusually high redox activity that are not directly required for active growth. Generally, the biological roles of these compounds have been ascribed to interspecies competition and virulence, and they have been considered important sources of distress.
In this review, we discuss two examples of redox-active metabolites: nitric oxide and phenazines. Both are known for their toxic effects in some organisms and conditions but have recently been shown to provide benefits for some organisms under other conditions.
Biologists are identifying new roles for redox-active metabolites that are not directly related to their toxicity. These roles prompt us to suggest a dismissal of the paradigm that all biological stress is negative (i.e., distress).
A more accurate view of redox couples requires characterization of their specific biological effects in a condition-dependent manner. The responses to these compounds can be termed "distress" or "eustress," depending on whether they inhibit survival, provide protection from a compound that would otherwise inhibit survival, or promote survival.
植物生物学家和微生物学家长期以来一直在讨论和争论所谓的“氧化还原活性代谢物”的生理作用。这些是具有异常高氧化还原活性的天然产物，它们不是主动生长所必需的。一般来说，这些化合物的生物学作用被归因于种间竞争和毒力，并且被认为是造成压力的重要来源。
在这篇综述中，我们讨论了两种氧化还原活性代谢物的例子：一氧化氮和吩嗪。两者都因其在某些生物体和条件下的毒性作用而闻名，但最近已经表明，在其他条件下，它们为一些生物体提供了益处。
生物学家正在为氧化还原活性代谢物确定与其毒性无关的新作用。这些作用促使我们摒弃所有生物压力都是负面的（即压力）的范式。
更准确地描述氧化还原对需要以条件依赖的方式描述它们特定的生物学效应。对这些化合物的反应可以被称为“压力”或“正压力”，这取决于它们是否抑制生存，是否提供对否则会抑制生存的化合物的保护，或者是否促进生存。
