The ATHB2 microProtein affects plant development and the shade avoidance response (PEAT)
Plants display remarkable adaptability to varying light conditions, crucial for their optimal growth and development. Here, we investigate the functional significance of ATHB2-miP, a microProtein arising from an alternative transcript of the ATHB2 gene, in both white light and shade environments, supported by comprehensive phenotyping experiments. ATHB2, a homeodomain-leucine zipper transcription factor, is known for its involvement in growth regulation. By employing genetic, transcriptomic analyses, and phenotyping experiments, we dissect the regulatory role of ATHB2-miP. Transcriptomics unravel genes differentially induced and repressed upon ATHB2-miP expression, elucidating its impact on growth-related pathways. Notably, ATHB2-miP's expression responds to shade conditions, suggesting its role in light-mediated responses. Our research underscores ATHB2-miP's multifaceted contribution to plant growth and development, emphasizing its potential as a pivotal player in light-responsive gene regulation. Overall design: We conducted transcriptomics, phenotyping studies, genetic analyses and protein interaction experiments on mutant lines generated by CRISPR-Cas9 where the microProein was deleted, a t-knockout line of the full ATHB2 gene and a line overexpressing the microProtein under the control of a 35S promoter.