Genome-wide identification and characterization of stress-responsive genes in Chlorella vulgaris

Chlorella vulgaris is a significant green alga that has a role in the bioremediation of environmental pollutants, especially heavy metals. Therefore, to meet the emerging needs of sustainable bioremediation, it is the need of the hour to improve the bioremediation potential of Chlorella vulgaris. Stress-related genes play significant roles in homeostasis and stress management in algal species, including C. vulgaris. It deals with varying pH and temperature, toxic heavy metals, oxidative stress, and many others. While certain stress-responsive proteins such as Heat Shock Proteins (HSPs) and Antioxidant Enzymes have been previously reported in C. vulgaris, this study aims to expand the scope by identifying and characterizing a diverse range of genes from various gene families, many of which have not been studied before in C. vulgaris.

A comprehensive analysis of the stress-related genes was conducted in which comparative phylogenetic analysis; conserved motif detection, determination of gene structure, and their subcellular localization were performed.

As a result of this study, 15 stress-related genes in C. vulgaris were annotated and characterized. The phylogenetic analysis represented that these genes evolved independently in C. vulgaris. Twenty highly conserved motifs amino acid structures have been exhibited. These motifs have a potential role in stress management. The proteins are localized at different locations in the cells. In parallel to genome-wide analysis, an experiment was conducted in a wet lab to evaluate the growth curve of C. vulgaris under Cd and pH stress.

The results revealed a probability that C. vulgaris has some mechanisms and genes that act as key players for survival. Moreover, this study not only provides identification and characterization of stress-related genes but also lays the foundation for further identification, annotation, and confirmation by expression profiling under different stress conditions such as toxic heavy metals and pH.