The discovery of the oxygen sensor in plants is published by Nature

23 October 2011
image description Nature publishes the discovery by scientists at the Scuola Superiore Sant’Anna, Pisa, Italy
In the next issue, the scientific journal Nature publishes a study revealing the key mechanism by which plants can become more tolerant to submergence. In the paper, the scientists from the Scuola Superiore Sant’Anna of Pisa (Italy), along with their colleagues from the Max Planck Institute of Golm (Germany) and Utrecht University (Netherlands) describe their findings: inside the plant cell a particular protein, called RAP2.12, is continuously degraded under normal plant growth conditions, when atmospheric oxygen is present. However, if oxygen availability decreases, RAP2.12 protein is stabilized and triggers the adaptive response of the plant, thereby enabling it to better tolerate the submergence induced oxygen deprivation.
Climatic changes are the hallmark of the last millennium and scientific research looks for answers allowing mankind to withstand their drawbacks. Extremely heavy rainfall events are registered with increasing frequency, whose effect is the complete flooding of wide cultivated
areas. Soil submergence limits or even nullifies oxygen availability for plants, thereby causing their death. Huge yield losses are the consequence of such climatic events, which can threaten national economy and often even survival of entire populations due to the famine. “Proteins are made up of aminoacid chains and aminoacids residing in the initial part of a protein prove to be very important in determining its stability”, explains Pierdomenico Perata, coordinator of the research group at the Sant’Anna School in Pisa. “We found out that the presence of a cysteine aminoacid is particularly destabilizing for the RAP2.12 protein, since oxygen can favour its oxidation, but when the plant is submerged the consequent low oxygen availability can protect cysteine from the oxidation process”. “RAP2.12 protein is, thus, stabilized by the absence of oxygen and carries out an essential role in activating genes that confer the plant the ability to survive for a long time even underwater”.
Flooding drastically reduces oxygen availability to plants. Remarkably, the impact of this finding might go beyond plant biology, as explained by Francesco Licausi, first author of the work. “The mechanism we uncovered is likely present in most of the living organisms, including humans. Oxygen plays indeed a fundamental role in human physiology and also has an impact in determining tumours resistance to chemotherapy”.
This study opens up new perspectives both in the agronomic area, for the selection of novel floodingresistant crop varieties, and in the field of basic research, as it may help us understand how oxygen, besides allowing us to breath, can modulate manifold aspects of human physiology.