Regulatory role of death specific protein in response to nutrient limitation in a marine diatom

Abstract

Microalgae encounter a range of adverse conditions which restricts algal biomass, thereby the primary productivity is constrained. Death-specific proteins (DSP) play a crucial role in orchestrating cellular growth under adverse conditions. However, the functional role of DSPs in diatoms remains scant. Here, we identified a DSP (designated as PtDSP) in the model diatom Phaeodactylum tricornutum and elucidated its role in alleviating cellular growth and photosynthesis in a stress-dependent manner. Plastid-localized PtDSP upheld the cellular physiological properties under specific stress conditions. Overexpression of PtDSP potentiated the cells to withstand iron deprivation rather than nitrogen and phosphorus deprivation. Under iron deprivation, PtDSP orchestrated the expression of key genes involved in photosynthesis, thereby combated iron deprivation. This report epitomizes the role of DSP in governing diatom physiological properties in a stress-dependent manner and advances our understanding of the systematic response of diatoms to environmental changes.