Plants often experience low-oxygen conditions, not only as an environmental stress condition but also as part of their normal developmental process. Oxygen deficiency signaling in the plant cell has been shown to involve reactive oxygen and nitrogen species, hormones, and calcium as secondary messengers, similarly to the low-oxygen signaling observed in other eukaryotic systems. However, in plants, evidences suggesting the existence on an oxygen sensor are scant. To date, research efforts have been aimed at understanding the strategies used by plants to low oxygen. Anatomical modifications, which encompass leaf elongation, adventitious rooting production and aerenchyma formation, can help the plants to avoid the stress consequent to low oxygen availability. On the other hand, metabolic adaptations enable the plant tissue to survive while experiencing oxygen deficiency, mainly coupling structural maintenance with energy saving. Application of the knowledge already available to crops may provide solutions for both agricultural and industrial processes involving low-oxygen conditions. © 2009 Elsevier Ltd. All rights reserved.
