Early Stage Adaptation of a Mesophilic Green Alga to Antarctica: Systematic Increases in Abundance of Enzymes and LEA Proteins.

ABSTRACT: It is known that adaptive evolution in permanently cold environments drives cold adaptation in enzymes. However, how the relatively high enzyme activities were achieved in cold environments prior to cold adaptation of enzymes is unclear. Here we report that an Antarctic strain of Chlorella vulgaris, called NJ-7, acquired the capability to grow at near 0 °C temperatures and greatly enhanced freezing tolerance after systematic increases in abundance of enzymes/proteins and positive selection of certain genes. Having diverged from the temperate strain UTEX259 of the same species 2.5 (1.1-4.1) to 2.6 (1.0-4.5) Ma, NJ-7 retained the basic mesophilic characteristics and genome structures. Nitrate reductases in the two strains are highly similar in amino acid sequence and optimal temperature, but

SUBMITTER: Wang Y 

PROVIDER: S-EPMC7038666 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature