Expression validation of two genes important for photosynthesis under low temperature conditions in different maize inbred lines

Abstract

As one of the most important metabolic processes in all plants, photosynthesis is necessary for their survival and ensuring enough energy is created for successful execution of all physiological processes, including nutrient intake and transport, interactions with the environment, growth and development, as well as processes important for crops and their production such as flowering, reproduction, grain filling etc. Many current strategies of avoiding yield loss in crop production include earlier sowing, as to avoid increasingly higher temperatures during late spring and summer, the consequences of climate change. Because of that, the knowledge of the impact of the cold on the process of photosynthesis is of crucial importance. In this research, we focused on the light dependent phase of photosynthesis and chose two genes related both to this phase and stress tolerance – photosystem II cytochrome b559 α-subunit and ATP synthase CF0 A subunit. These genes were chosen for further research from a set of differentially expressed genes (DEGs) detected between Lancaster and non-Lancaster maize lines. Their expression was validated on four maize inbred lines that belonged to different heterotic groups (Lancaster and non-Lancaster). The experiment was performed under optimal and low temperatures, 22° and 6° respectively, during the V4 growth stage. Samples for RNA extraction, cDNA synthesis and qPCR expression validation were taken after 6h and 24h of exposure to experimental temperatures, as well as after 48h in recovery. Results showed significant changes in the expression of these genes, both between different time points of stress treatment, as well as between different inbred lines. These preliminary results give a good base for further studies of gene expression in important maize lines, particularly abiotic stress related genes, as a tool for establishing successful breeding programs and defining pathways involved in maize response to cold stress.