Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.
Plant Mol Biol. 2020 Jun;103(3):321-340. doi: 10.1007/s11103-020-00994-0. Epub 2020 Apr 10.
Plants live in constantly changing and often unfavorable or stressful environments. Environmental changes induce biotic and abiotic stress, which, in turn, may cause genomic DNA damage. Hence, plants simultaneously suffer abiotic/biotic stress and DNA damage. However, little information is available on the signaling crosstalk that occurs between DNA damage and abiotic/biotic stresses. Arabidopsis thaliana SUPPRESSOR OF GAMMA RESPONSE1 (SOG1) is a pivotal transcription factor that regulates thousands of genes in response to DNA double-strand break (DSB), and we recently reported that SOG1 has a role in immune responses. In the present study, the effects of SOG1 overexpression on the DNA damage and immune responses were examined. Results found that SOG1 overexpression enhances the regulation of numerous downstream genes. Relative to the wild type plants, then, DNA damage responses were observed to be strongly induced. SOG1 overexpression also upregulates chitin (a major components of fungal cell walls) responsive genes in the presence of DSBs, implying that pathogen defense response is activated by DNA damage via SOG1. Further, SOG1 overexpression enhances fungal resistance. These results suggest that SOG1 regulates crosstalk between DNA damage response and the immune response and that plants have evolved a sophisticated defense network to contend with environmental stress.
植物生活在不断变化的环境中，这些环境往往对它们不利或充满压力。环境变化会引发生物和非生物胁迫，进而导致基因组 DNA 损伤。因此，植物同时遭受非生物/生物胁迫和 DNA 损伤。然而，关于 DNA 损伤与非生物/生物胁迫之间发生的信号转导串扰，我们知之甚少。拟南芥 SUPPRESSOR OF GAMMA RESPONSE1（SOG1）是一种关键的转录因子，可响应 DNA 双链断裂（DSB）调节数千个基因，我们最近报道 SOG1 在免疫反应中发挥作用。在本研究中，研究了 SOG1 过表达对 DNA 损伤和免疫反应的影响。结果发现，SOG1 过表达增强了对众多下游基因的调控。与野生型植物相比，观察到 DNA 损伤反应强烈诱导。SOG1 过表达还上调了 DSB 存在时几丁质（真菌细胞壁的主要成分）反应基因的表达，这意味着通过 SOG1 激活了对病原体防御反应。此外，SOG1 过表达增强了对真菌的抗性。这些结果表明，SOG1 调节 DNA 损伤反应与免疫反应之间的串扰，植物已经进化出复杂的防御网络来应对环境胁迫。
