LTS3 gene controls light-independent chlorophyll biosynthesis in green algae Chlamydomonas reinhardtii

Abstract

The genetic control of light-independent chlorophyll biosynthesis in plant cells has been investigated using Chlamydomonas reinhardtii Lts3-mutants defective in dark chlorophyll biosynthesis on the stage before protochlorophyllide to chlorophyllide conversion. In heterotrophic conditions the mutants are unable to synthesize chlorophyll and accumulate protoporphyrins, after illumination they are greening. The mutants were tested for pigment contents, activity of enzymes and expression of the genes, encoding these enzymes. The LTS3 gene has been identified by positional cloning, and the predicted LTS3 protein appeared to be a GATA transcription factor, which activate the expression of genes encoded chlorophyll biosynthesis enzymes: Mg-chelatase and glutamate 1-semialdehyde aminotransferase in the dark, and possibly, important for adaptation of plant cells for autotrophic conditions.

Optimization of CRISPR/Cas9 method for transgenesis of model microalgae <i>Chlamydomonas reinhardtii</i>

“…To test and optimize the TIM technique [2] in our lab, we carried out a knockout of the LTS3 gene, a transcriptional activator of chlorophyll biosynthesis genes in heterotrophic conditions [3].…”