Investigation of Root Zone Phytoene Synthase (PSY) and Alfin (ALF) Gene Expression in Salt Stressed Zea mays Inbred Lines Mo17 & B73
Keywords:phytoene synthase, salinity, maize, roots
Carotenoids are plant pigments that function in photoprotectection, photosynthesis, and abiotic stress response. Soil salinity, an abiotic stressor, negatively impacts crop yields worldwide. Phytoene synthase (PSY) is the first dedicated enzyme in the carotenoid biosynthetic pathway, ultimately producing the stress hormone abscisic acid. In maize, PSY is encoded by three sub-functionalized genes: PSY1, PSY2, and PSY3, which are differentially expressed in root zones. How PSY expression is affected by salt stress is not well understood in US inbred lines. To determine the effects of salinity on PSY expression in developing roots, maize seedlings were grown in increasing salt concentrations. Root and shoot growth were assessed and the expression of PSY quantified in primary root zones. Expression of two Alfin (ALF) genes, also involved in stress responses, were measured. Increasing salt concentrations significantly stunted seedling growth and differentially altered the expression of PSY and ALF genes in primary root zones.