Enzymology and Molecular Biology

Biography

Biography: Iwona Żur

Abstract

The technology of doubled haploids as the fastest route to total homozygosity is highly appreciated in many domains of basic research and breeding. Among several methods, the one using isolated and in vitro-cultured immature cells of male gametophyte induced towards embryogenic development (microspore embryogenesis-ME) possesses the highest potential for commercial application. However, efficient ME induction requires a precisely balanced stress treatment, strong enough to induce microspore reprogramming but not exceeding cell stress tolerance threshold. As the general cause of injuries in in vitro-cultured cells is the overproduction of reactive oxygen species (ROS), an efficient antioxidative defence was suggested as the first prerequisite for stress survival and effective ME initiation. To establish the role of ROS and the antioxidative system in ME initiation, the generation of hydrogen peroxide, and the activities of antioxidative enzymes and low molecular weight antioxidants were analysed in isolated microspores of two cultivars of barley (Hordeum vulgare L.), winter cv. Igri and spring cv. Golden Promise, differing significantly with respect to embryogenic potential. The analyses were conducted in microspores redirected towards embryogenic development by low temperature tillers pre-treatment (4 weeks at 4°C). Additionally, the effects of compounds known as cellular redox status modifiers, e.g. glutathione and L-2-oxo-4-thiazolidinecarboxylic acid (OTC), on microspore viability and ME initiation efficiency were estimated. The received results suggest that the activity of the antioxidative system is the first prerequisite for successful ME initiation, though in the case of its low activity, antioxidative defence could be supported by the application of exogenous antioxidants.