Bailey-Serres J, Voesenek L A C J
Center for Plant Cell Biology, University of California, Riverside, California 92521, USA.
Annu Rev Plant Biol. 2008;59:313-39. doi: 10.1146/annurev.arplant.59.032607.092752.
Flooding is an environmental stress for many natural and man-made ecosystems worldwide. Genetic diversity in the plant response to flooding includes alterations in architecture, metabolism, and elongation growth associated with a low O(2) escape strategy and an antithetical quiescence scheme that allows endurance of prolonged submergence. Flooding is frequently accompanied with a reduction of cellular O(2) content that is particularly severe when photosynthesis is limited or absent. This necessitates the production of ATP and regeneration of NAD(+) through anaerobic respiration. The examination of gene regulation and function in model systems provides insight into low-O(2)-sensing mechanisms and metabolic adjustments associated with controlled use of carbohydrate and ATP. At the developmental level, plants can escape the low-O(2) stress caused by flooding through multifaceted alterations in cellular and organ structure that promote access to and diffusion of O(2). These processes are driven by phytohormones, including ethylene, gibberellin, and abscisic acid. This exploration of natural variation in strategies that improve O(2) and carbohydrate status during flooding provides valuable resources for the improvement of crop endurance of an environmental adversity that is enhanced by global warming.
洪水对全球许多自然和人工生态系统来说都是一种环境压力。植物对洪水的遗传多样性反应包括结构、新陈代谢和伸长生长的改变，这些改变与低氧逃逸策略以及一种相反的静止机制相关，该静止机制能使植物耐受长时间的淹没。洪水常常伴随着细胞含氧量的降低，当光合作用受到限制或不存在时，这种情况尤为严重。这就需要通过无氧呼吸产生ATP并再生NAD⁺。对模型系统中基因调控和功能的研究有助于深入了解低氧感知机制以及与碳水化合物和ATP的可控利用相关的代谢调整。在发育层面，植物可以通过细胞和器官结构的多方面改变来逃避洪水造成的低氧胁迫，这些改变促进了氧气的获取和扩散。这些过程由植物激素驱动，包括乙烯、赤霉素和脱落酸。对洪水期间改善氧气和碳水化合物状况的策略中的自然变异进行的探索，为提高作物对因全球变暖而加剧的环境逆境的耐受性提供了宝贵资源。
