Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands.
Plant Physiol. 2018 Feb;176(2):1106-1117. doi: 10.1104/pp.17.01232. Epub 2017 Nov 2.
Flooding is detrimental for nearly all higher plants, including crops. The compound stress elicited by slow gas exchange and low light levels under water is responsible for both a carbon and an energy crisis ultimately leading to plant death. The endogenous concentrations of four gaseous compounds, oxygen, carbon dioxide, ethylene, and nitric oxide, change during the submergence of plant organs in water. These gases play a pivotal role in signal transduction cascades, leading to adaptive processes such as metabolic adjustments and anatomical features. Of these gases, ethylene is seen as the most consistent, pervasive, and reliable signal of early flooding stress, most likely in tight interaction with the other gases. The production of reactive oxygen species (ROS) in plant cells during flooding and directly after subsidence, during which the plant is confronted with high light and oxygen levels, is characteristic for this abiotic stress. Low, well-controlled levels of ROS are essential for adaptive signaling pathways, in interaction with the other gaseous flooding signals. On the other hand, excessive uncontrolled bursts of ROS can be highly damaging for plants. Therefore, a fine-tuned balance is important, with a major role for ROS production and scavenging. Our understanding of the temporal dynamics of the four gases and ROS is basal, whereas it is likely that they form a signature readout of prevailing flooding conditions and subsequent adaptive responses.
洪水对包括作物在内的几乎所有高等植物都有害。在水下缓慢的气体交换和低光照水平下产生的复合应激导致了碳和能量危机，最终导致植物死亡。在植物器官被淹没在水中的过程中，四种气态化合物（氧气、二氧化碳、乙烯和一氧化氮）的内源性浓度会发生变化。这些气体在信号转导级联中起着关键作用，导致适应过程，如代谢调整和解剖特征。在这些气体中，乙烯被认为是早期水淹胁迫最一致、最普遍和最可靠的信号，很可能与其他气体密切相互作用。在植物细胞中产生的活性氧物质 (ROS) 在洪水期间和沉降后直接产生，在此期间植物面临高光照和氧气水平，这是这种非生物胁迫的特征。低水平、良好控制的 ROS 水平对于与其他气态洪水信号相互作用的适应性信号通路是必不可少的。另一方面，ROS 的过度失控爆发对植物有很高的破坏性。因此，精细的平衡很重要，ROS 的产生和清除起着重要作用。我们对这四种气体和 ROS 的时间动态的理解是基础的，而它们很可能形成当前洪水条件和随后的适应反应的特征读数。
