Ethylene signaling of hypoxic stress adaptation in Arabidopsis

植物是需氧生物。氧气过少（缺氧）使能量供应困难，导致植物代谢受损。植物缺氧甚至缺氧（缺氧）的常见原因是土壤积水和淹没。取决于它们的生态位，植物或多或少能很好地适应低氧胁迫。在洪水中，气体激素乙烯在植物组织中迅速积累。乙烯控制了许多适应性，提高了植物在洪水期间的存活率。在模式植物拟南芥中，乙烯调节下部叶柄的生长，这有助于将叶片移出水面。乙烯信号和缺氧信号进一步调节代谢适应低氧胁迫。AP2/ERF （apetala2/乙烯响应因子）转录因子被确定为植物对洪水响应的关键介质。拟南芥ERFs RAP2.2和ERF73先前被证明受缺氧和乙烯的调节，当过表达时，两者都增加了对低氧胁迫的耐受性。本项目旨在通过RAP2.2和ERF73阐明乙烯信号在拟南芥缺氧适应中的作用。为此，我们将澄清RAP2.2和ERF73是否有重叠和/或独特的功能。我们将确定这些转录因子在常氧和缺氧条件下或暴露于乙烯时靶向的基因。我们将探讨RAP2.2和ERF73是否介导了拟南芥在低氧胁迫适应中的全乙烯响应。我们期望我们的研究将为我们对缺氧胁迫耐受性的乙烯信号的理解提供重要的贡献。

Plants are aerobic organisms. Too little oxygen (hypoxia) renders energy supply difficult and results in impaired plant metabolism. Common causes for hypoxic or even anoxic (lack of oxygen) conditions in plants are soil water logging and submergence. Depending on their ecological niche, plants are more or less well adapted to cope with low oxygen stress. The gaseous hormone ethylene rapidly accumulates in plant tissues upon flooding. Ethylene controls many adaptations that improve plant survival during flooding. In the model plant Arabidopsis thaliana ethylene regulates hyponastic petiole growth which helps to move the leaf above the water surface. Ethylene signaling in concert with hypoxia signaling furthermore regulates metabolic adaptation to low oxygen stress. AP2/ERF (apetala2/ethylene response factor) transcription factors were identified as key mediators of plant responses to flooding. The Arabidopsis thaliana ERFs RAP2.2 and ERF73 were previously shown to be regulated by hypoxia and by ethylene and both increase tolerance to low oxygen stress when overexpressed. The proposed project aims to elucidate the contribution of ethylene signaling to hypoxia adaptation via RAP2.2 and ERF73 in Arabidopsis thaliana. To this end, we will clarify if RAP2.2 and ERF73 have overlapping and/or unique functions. We will identify genes that are targeted by these transcription factors at normoxic and hypoxic conditions or when exposed to ethylene. And we will ask if RAP2.2 and ERF73 mediate the full ethylene response in hypoxic stress adaptation in Arabidopsis. We expect that our study will provide a major contribution to our understanding of ethylene signaling of hypoxic stress tolerance.