C<sub>4</sub> gene induction during de-etiolation evolved through changes in cis to allow integration with ancestral C<sub>3</sub> gene regulatory networks.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36989352.
- Also identified by DOI 10.1126/sciadv.ade9756 and PMC identifier 10058240.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
C<sub>4</sub> photosynthesis has evolved by repurposing enzymes found in C<sub>3</sub> plants. Compared with the ancestral C<sub>3</sub> state, accumulation of C<sub>4</sub> cycle proteins is enhanced. We used de-etiolation of C<sub>4</sub> <i>Gynandropsis gynandra</i> and C<sub>3</sub> <i>Arabidopsis thaliana</i> to understand this process. C<sub>4</sub> gene expression and chloroplast biogenesis in <i>G. gynandra</i> were tightly coordinated. Although C<sub>3</sub> and C<sub>4</sub> photosynthesis genes showed similar induction patterns, in <i>G. gynandra</i>, C<sub>4</sub> genes were more strongly induced than orthologs from <i>A. thaliana</i>. In vivo binding of TGA and homeodomain as well as light-responsive elements such as G- and I-box motifs were associated with the rapid increase in transcripts of C<sub>4</sub> genes. Deletion analysis confirmed that regions containing G- and I-boxes were necessary for high expression. The data support a model in which accumulation of transcripts derived from C<sub>4</sub> photosynthesis genes in C<sub>4</sub> leaves is enhanced because modifications in cis allowed integration into ancestral transcriptional networks.
Medical subject headings
- Gene Regulatory Networks
- Etiolation