Reactive oxygen species and their influence on mediating salinity tolerance mecahnisms in Triticum aestivum

Abstract

Soil salinity has detrimental impact on wheat productivity and since wheat is amongst the most important crops for human consumption, soil salinization imposes a major threat to global food security. Currently we know three mechanisms in which plants withstand salinity stress, namely, ion exclusion, tolerance to osmotic stress and tissue tolerance. Although significant research efforts have elucidated the genetic regulations occurring in the exclusion of ions, as well as compartmentalization of ions at the cellular level and thereby enhancing tissue tolerance, it still remains largely unknown which genes mediate osmotic stress tolerance. Osmotic stress causes oxidative damage because of the accumulation of reactive oxygen species (ROS). Plants are capable of removing ROS with antioxidant systems. The mechanisms in which ROS remains in balance across the three salinity tolerance mechanisms in wheat have never been studied yet. In short, there are two gaps in our understanding of salinity tolerance in wheat, namely, the limited amounts of candidate genes discovered that influence salinity tolerance and the lack of understanding on the role of ROS metabolism in mediating the known salinity tolerance mechanisms. In this research, I aim to identify novel gene candidates associated with salinity tolerance through genome-wide association mapping. Subsequently, I aim to identify how ROS metabolism influences salinity tolerance in genes previously identified to be associated with the salinity tolerance mechanisms, as well as possible gene candidates we discover in the GWAS. The outcome of this research will improve our understanding on salinity tolerance and is pivotal for salinity tolerant crop breeding.