Whitney L.A.S.,University of Pisa |
Loreti E.,National Research Council Italy |
Alpi A.,University of Pisa |
New Phytologist | Year: 2011
The unicellular green alga Chlamydomonas reinhardtii contains two iron (Fe)-hydrogenases which are responsible for hydrogen production under anoxia. In the present work the patterns of expression of alcohol dehydrogenase, a typical anaerobic gene in plants, of the hydrogenases genes (HYD1, HYD2) and of the genes responsible for their maturation (HYDEF, HYDG), were analysed. The expression patterns were analysed by real-time reverse-transcription polymerase chain reaction in Chlamydomonas cultures during the day-night cycle, as well as in response to oxygen availability. The results indicated that ADH1, HYD1, HYD2, HYDEF and HYDG were expressed following precise day-night fluctuations. ADH1 and HYD2 were modulated by the day-night cycle. Low oxygen plays an important role for the induction of HYD1, HYDEF and HYDG, while ADH1 and HYD2 expression was relatively insensitive to oxygen availability. The regulation of the anaerobic gene expression in Chlamydomonas is only partly explained by responses to anoxia. The cell cycle and light-dark cycles are equally important elements in the regulatory network modulating the anaerobic response in Chlamydomonas. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).
Van Dongen J.T.,RWTH Aachen |
Annual Review of Plant Biology | Year: 2015
Oxygen is an indispensable substrate for many biochemical reactions in plants, including energy metabolism (respiration). Despite its importance, plants lack an active transport mechanism to distribute oxygen to all cells. Therefore, steep oxygen gradients occur within most plant tissues, which can be exacerbated by environmental perturbations that further reduce oxygen availability. Plants possess various responses to cope with spatial and temporal variations in oxygen availability, many of which involve metabolic adaptations to deal with energy crises induced by low oxygen. Responses are induced gradually when oxygen concentrations decrease and are rapidly reversed upon reoxygenation. A direct effect of the oxygen level can be observed in the stability, and thus activity, of various transcription factors that control the expression of hypoxia-induced genes. Additional signaling pathways are activated by the impact of oxygen deficiency on mitochondrial and chloroplast functioning. Here, we describe the molecular components of the oxygen-sensing pathway. ©2015 by Annual Reviews. All rights reserved.
PlantLab | Date: 2015-05-08
Pucciariello C.,PlantLab |
Plant Signaling and Behavior | Year: 2012
The recent identification of the oxygen-sensing mechanism in plants is a breakthrough in plant physiology. The presence of a conserved N-terminal motif on some Ethylene Responsive Factors (ERFs), targets the protein for post-translational modifications finally leading to degradation under normoxia and thus providing a mechanism for sensing the presence of oxygen. The stabilization of the N-terminus under low oxygen activates these ERFs, which regulate low oxygen core genes that enable plants to tolerate abiotic stress such as flooding. Additional mechanisms that signal low-oxygen probably also exist, and the production of Reactive Oxygen Species (ROS) has been observed under low oxygen, suggesting that ROS might be part of the network involved in plant acclimation. Here, we review the most recent findings related to oxygen sensing. © 2012 Landes Bioscience.
Pucciariello C.,PlantLab |
Trends in Plant Science | Year: 2013
Rice (Oryza sativa) varieties differ considerably in their tolerance to submergence, a trait that has been associated with the SUB1A gene. Recently, this gene was found in some wild rice species and landraces, which along with O. sativa, belong to the AA genome type group. On the basis of geographical and historical data, we hypothesize that SUB1A-1 from wild species may have been introgressed into domesticated rice. This introgression probably occurred in the Ganges Basin, with the subsequent spread of the SUB1A-1 to other areas of South Asia due to human migration. The lack of the SUB1A gene in diploid CC genome type wild rice showing submergence-tolerant traits suggests the presence of a different survival mechanism in this genetic group. © 2013 Elsevier Ltd.