A alga Antártica Prasiola crispa: um modelo para entender a vida em condições extremas

Abstract

Antarctica, located at the Earth's South Pole, has broad distribution and biodiversity patterns related to abiotic factors. Plants are limited to species that evolved molecular strategies for survival, such as the differential expression of low temperature responsive genes. Among these is the algae Prasiola crispa, found in thawed areas of Antarctica. Molecular information about this species is still scarce. With the development of sequencing technologies, producing new data enabled more accurately phylogenomic and transcriptomic analysis. Phylogenetic studies consider processes that act on entire genomes. Organelle genomes are great sources of phylogenetic data, including protein sequences and information about genetic content and architecture. Transcriptomic analysis uses the set of all expressed transcripts. In this work, we used chloroplast (cpDNA) and mitochondrial (mtDNA) genome data to infer the evolutionary relationships of P. crispa and other green algae species, as well as a structural genomics analysis. We also sequenced, assembled and annotated the transcriptome of P. crispa, aiming to identify gene products related to the ability to survive in the Antarctic continent. Through cpDNA-based phylogenomic analysis, we were able to observe the formation of the Prasiola clade, composed of P. crispa, Prasiolopsis sp. and Stichococcis bacilaris. The results of the mtDNA analysis demonstrated the grouping of P. crispa and other species of algae of the class Trebouxiophyceae. Synthenic analysis of P. crispa and evolutionarily related green plant species showed few synthetic gene blocks. In the transcriptomic analysis, we identified 17,201 contigs. The information generated in this work demonstrates that accessory genomes are valuable tools for evolutionary analysis and the transcriptome data provided the first insights into the molecular dynamics of P. crispa in the Antarctic environment. The genes and biomolecules involved in the survival process of P. crispa are of great interest and potencial in the field of Biotechnology.