Borisjuk Ljudmilla, Rolletschek Hardy
Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstr. 3, D-06466 Gatersleben, Germany.
New Phytol. 2009;182(1):17-30. doi: 10.1111/j.1469-8137.2008.02752.x. Epub 2008 Oct 1.
Recent applications of oxygen-sensitive microsensors have demonstrated steep oxygen gradients in developing seeds of various crops. Here, we present an overview on oxygen distribution, major determinants of the oxygen status in the developing seed and implications for seed physiology. The steady-state oxygen concentration in different seed tissues depends on developmental parameters, and is determined to a large extent by environmental factors. Photosynthetic activity of the seed significantly diminishes hypoxic constraints, and can even cause transient, local hyperoxia. Changes in oxygen availability cause rapid adjustments in mitochondrial respiration and global metabolism. We argue that nitric oxide (NO) is a key player in the oxygen balancing process in seeds, avoiding fermentation and anoxia in vivo. Molecular approaches aiming to increase oxygen availability within the seed are discussed.
氧敏感微传感器的最新应用已证明，多种作物发育中的种子存在陡峭的氧梯度。在此，我们概述了发育中种子的氧分布、氧状态的主要决定因素及其对种子生理学的影响。不同种子组织中的稳态氧浓度取决于发育参数，并在很大程度上由环境因素决定。种子的光合活性显著减轻了缺氧限制，甚至可能导致短暂的局部高氧。氧可利用性的变化会导致线粒体呼吸和整体代谢的快速调整。我们认为，一氧化氮（NO）是种子氧平衡过程中的关键参与者，可避免体内发酵和缺氧。本文还讨论了旨在提高种子内氧可利用性的分子方法。
