B‐GATA factors are required to repress high‐light stress responses in Marchantia polymorpha and Arabidopsis thaliana

Abstract

GATAs are evolutionarily conserved zinc‐finger transcription factors from eukaryotes. In plants, GATAs can be subdivided into four classes, A–D, based on their DNA‐binding domain, and into further subclasses based on additional protein motifs. B‐GATAs with a so‐called leucine‐leucine‐methionine (LLM)‐domain can already be found in algae. In angiosperms, the B‐GATA family is expanded and can be subdivided in to LLM‐ or HAN‐domain B‐GATAs. Both, the LLM‐ and the HAN‐domain are conserved domains of unknown biochemical function. Interestingly, the B‐GATA family in the liverwort Marchantia polymorpha and the moss Physcomitrium patens is restricted to one and four family members, respectively. And, in contrast to vascular plants, the bryophyte B‐GATAs contain a HAN‐ as well as an LLM‐domain. Here, we characterise mutants of the single B‐GATA from Marchantia polymorpha. We reveal that this mutant has defects in thallus growth and in gemma formation. Transcriptomic studies uncover that the B‐GATA mutant displays a constitutive high‐light (HL) stress response, a phenotype that we then also confirm in mutants of Arabidopsis thaliana LLM‐domain B‐GATAs, suggesting that the B‐GATAs have a protective role towards HL stress.

AP2/ERF transcription factors enriched in the drought-response transcriptome of the Thar desert treeProsopis cinerariashow higher copy number and greater DNA-binding affinity than orthologs in drought-sensitive species

“…Other cis-elements, including MYB and MYC, indicate the complex regulation of P. cineraria AP2/ERFs by different families of TFs under drought stress (Abe et al 2003). Moreover, we found that the promoter regions of AP2/ERF genes contained elements related to light response, such as the G-box and GATA motif (Luo et al 2010;Schröder et al 2023).…”

Streamlined regulation of chloroplast development in the liverwort Marchantia polymorpha

“…The role of PpGATA orthologs (including both PpGATA1 and PpGATA2), therefore needs additional analysis to confirm or refute their role in chloroplast biogenesis. A recent study in M. polymorpha proposed a role in response to high-light stress 43 for MpGATA4 with mutants showing mis-regulation of genes encoding EARLY LIGHT INDUCED PROTEINs (ELIPs).…”

“…The role of PpGATA orthologs (including both PpGATA1 and PpGATA2), therefore, needs additional analysis to confirm or refute their role in chloroplast biogenesis. A recent study of MpGATA4 in M. polymorpha proposed a role in response to highlight stress (Schröder et al, 2023) with Early Light Induced Protein (ELIP) encoding genes being mis-regulated in Mpgata4 mutants. Our transcriptome analysis of Mpgata4 mutants revealed that only a single ELIP gene (MpELIP-11) is moderately downregulated (Log2FC=-0.678) alongside a small number of genes encoding components of the LHC and PS.…”