Ecology and Biodiversity, Institute of Environmental Biology, Utrecht University, 3584 CH, Utrecht, The Netherlands.
Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH, Utrecht, The Netherlands.
Microbiome. 2018 Mar 21;6(1):52. doi: 10.1186/s40168-018-0436-1.
The plant hormone ethylene is one of the central regulators of plant development and stress resistance. Optimal ethylene signaling is essential for plant fitness and is under strong selection pressure. Plants upregulate ethylene production in response to stress, and this hormone triggers defense mechanisms. Due to the pleiotropic effects of ethylene, adjusting stress responses to maximize resistance, while minimizing costs, is a central determinant of plant fitness. Ethylene signaling is influenced by the plant-associated microbiome. We therefore argue that the regulation, physiology, and evolution of the ethylene signaling can best be viewed as the interactive result of plant genotype and associated microbiota. In this article, we summarize the current knowledge on ethylene signaling and recapitulate the multiple ways microorganisms interfere with it. We present ethylene signaling as a model system for holobiont-level evolution of plant phenotype: this cascade is tractable, extremely well studied from both a plant and a microbial perspective, and regulates fundamental components of plant life history. We finally discuss the potential impacts of ethylene modulation microorganisms on plant ecology and evolution. We assert that ethylene signaling cannot be fully appreciated without considering microbiota as integral regulatory actors, and we more generally suggest that plant ecophysiology and evolution can only be fully understood in the light of plant-microbiome interactions.
植物激素乙烯是植物发育和抗逆性的中心调节因子之一。最佳的乙烯信号传导对于植物的适应性至关重要，并且受到强烈的选择压力。植物会响应胁迫而上调乙烯的产生，而这种激素会引发防御机制。由于乙烯的多效性，调整应激反应以最大程度地提高抗性，同时最小化成本，是植物适应性的核心决定因素。乙烯信号受到植物相关微生物组的影响。因此，我们认为，乙烯信号的调节、生理学和进化可以最好地被视为植物基因型和相关微生物组的相互作用结果。在本文中，我们总结了目前关于乙烯信号的知识，并回顾了微生物干扰它的多种方式。我们将乙烯信号作为植物表型的整体共生体进化的模型系统：这个级联是可处理的，从植物和微生物的角度来看，它都得到了极其深入的研究，并且调节了植物生活史的基本组成部分。我们最后讨论了微生物对植物生态学和进化的潜在影响。我们断言，如果不将微生物视为完整的调节因子，就无法充分理解乙烯信号，我们更普遍地认为，只有在考虑到植物-微生物组相互作用的情况下，才能全面理解植物生理生态和进化。
