Sub-theme 1e - Managing legume oxidative stress through altered mitochondrial activity
Abiotic stress inevitably results in oxidative stress within cells, arising from the formation of highly toxic reactive oxygen species (ROS), such as superoxide, hydrogen peroxide, etc., which can cause extensive damage to the cell and disrupt its metabolism. The ability of a plant to tolerate various environmental stresses is at least in part linked to its capacity to limit the production of ROS. One of the early responses of plants (including chickpea, (Molina et al., 2011; Fuente Burguillo & Nicolas, 1977)) to environmental stress is the enhanced activity of the Alternative Pathway (AP) of mitochondrial electron transport, which helps to minimise oxidative damage. Mitochondria are also intimately implicated in the signalling pathways that coordinate other antioxidant defence mechanisms in the cell. Changes in AP impact on the whole cell scavenging system and on how a cell manages ROS.
A number of studies have shown that increased activity of the alternative oxidase (AOX) and external NADH dehydrogenases (NDBs) occur under abiotic stress and that genetic manipulation of these AP mitochondrial components in Arabidopsis thaliana, enhances tolerance to salinity, drought and high/low temperatures. Interacting across research Theme 1, we will investigate the role of the AP in chickpea abiotic stress tolerance, with the aim of manipulating components to enhance tolerance to oxidative stress.
Outcomes will include identification of molecular markers to assist breeding for stress tolerance and genetically improved lines with enhanced tolerance to multiple environmental stresses.