SOG1, a plant‐specific master regulator of DNA damage responses, originated from nonvascular land plants

Abstract

The suppressor of gamma response 1 (SOG1), a NAM, ATAF1, 2, and CUC2 (NAC)-type transcription factor found in seed plants, is a master regulator of DNA damage responses (DDRs). Upon DNA damage, SOG1 regulates the expression of downstream DDR genes. To know the origin of the DDR network in land plants, we searched for a homolog(s) of SOG1 in a moss Physcomitrium (Physcomitrella) patens and identified PpSOG1a and PpSOG1b. To assess if either or both of them function(s) in DDR, we knocked out the PpSOG1s using CRISPR/Cas9-mediated gene editing and analyzed the responses to DNA-damaging treatments. The double-knockout (KO) sog1a sog1b plants showed resistance to γ-rays, bleomycin, and ultraviolet B (UVB) treatments similarly seen in Arabidopsis sog1 plants. Next, we irradiated wild-type (WT) and KO plants with γ-rays and analyzed the whole transcriptome to examine the effect on the expression of DDR genes. The results revealed that many P. patens genes involved in the checkpoint, DNA repair, replication, and cell cyclerelated genes were upregulated after γ-irradiation, which was not seen in sog1a sog1b plant. These results suggest that PpSOG1a and PpSOG1b work redundantly on DDR response in P. patens; in addition, plant-specific DDR systems had been established before the emergence of vascular plants.

Comparative Analysis of the Effect of Gamma-, Electron, and Proton Irradiation on Transcriptomic Profile of Hordeum vulgare L. Seedlings: In Search for Molecular Contributors to Abiotic Stress Resilience

“…Among other interesting upregulated transcripts is a gene, HORVU.MOREX.r3.5HG0512410, homologous to a negative regulator of p53 (Supplementary Table S1). The equivalent of p53 in plants is SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1) [42], and upregulation of its negative regulator may reflect control of double-strand break plant responses. Significant downregulation was observed for three transcripts (Figure 2B, Supplementary Table S1): BaRT2v18chr7HG356510, HORVU.MOREX.r3.6HG0545390 (BaRT2v18chr6HG285660), and HORVU.MOREX.r3.6HG0539130, which encode membrane protein kinases.…”

“…Dosimetry was performed using a PTW Farmer chamber type 30013 (PTW-Freiburg GmbH, Freiburg im Breisgau, Germany) and a PTW Unidose webline electrometer in a water-equivalent solid-state phantom PTW RW3 Slab (PTW-Freiburg GmbH, Germany). Measurements were executed according to TRS 398 recommendations [42]. The heterogeneity of the irradiation field was checked using 2D array of PTW Octavius 1500XDR ionisation cameras (PTW-Freiburg GmbH, Germany) and did not exceed 5% in the irradiation area in all directions (3% for proton irradiation).…”