Effect of light regime in superoxide dismutase expression in microalgae dunaliella salina

Abstract

Photosynthetic organisms, such as unicellular green algae have photo-protective mechanisms that are critical for survival under conditions of excess photon absorption. The absorbed light energy which is more than needed can excitate electrons of photosystem, and generate of reactive oxygen species(ROS). Living organisms evolved antioxidant defense mechanisms to remove excess O2- and H2O2. Superoxide dismutase is a metaloenzyme which catalyzes conversion of O2-(superoxide anion) to H2O2 and O2. Generally, localization of Fe-SOD is in the chloroplast and the function of this protein is considered as photo-protective role. In this work. we isolated cDNA of Fe-SOD and investigated the regulation of Fe-SOD in Dunaliella salina. Northern blot analysis revealed that the expression of Fe-SOD was affected by photo-period as well as light intensity. We will discuss the characterization of light regulations of Fe-SDO in Dunaliella salina more in detail.