Responses to sunlight exposure of the oil-degrading Dietzia cinnamea P4 strain were evaluated by transcriptional levels of SOS genes, photoreactivation and genes involved in tolerance to high levels of reactive oxygen species. The P4 strain was exposed for 1 and 2 h and the magnitude of level changes in the mRNA was evaluated by qPCR. The results described the activation of the SOS system, with the decline of the repressor lexA gene levels and the concomitant increase of recA and uvrAD genes levels. The genes that participate in the photoreactivation process were also responsive to sunlight. The phrB gene encoding deoxyribodipyrimidine photo-lyase had its expression increased after 1-h exposure, while the phytAB genes showed a progressive increase over the studied period. The protective genes against reactive oxygen species, catalases, superoxides, peroxidases, and thioredoxins, had their expression rates detected under the conditions validated in this study. These results show a fast and coordinated response of genes from different DNA repair and tolerance mechanisms employed by strain P4, suggesting a complex concerted protective action against environmental stressors.

中文翻译：

---

Dietzia cinnamea P4 菌株对阳光模拟器的适应性转录反应

通过 SOS 基因的转录水平、光再激活和涉及对高水平活性氧的耐受性的基因，评估了油降解的 Dietzia cinnamea P4 菌株对阳光照射的反应。P4 菌株暴露 1 和 2 小时，并通过 qPCR 评估 mRNA 水平变化的幅度。结果描述了 SOS 系统的激活，伴随着阻遏物 lexA 基因水平的下降和伴随的 recA 和 uvrAD 基因水平的增加。参与光活化过程的基因也对阳光有反应。编码脱氧核糖二嘧啶光裂解酶的 phrB 基因在暴露 1 小时后其表达增加，而 phytAB 基因在研究期间表现出逐渐增加。针对活性氧、过氧化氢酶、超氧化物、过氧化物酶和硫氧还蛋白在本研究中验证的条件下检测到它们的表达率。这些结果显示来自菌株 P4 所采用的不同 DNA 修复和耐受机制的基因的快速和协调反应，表明对环境压力源的复杂协同保护作用。