Roldán-Arjona Teresa, Ariza Rafael R, Córdoba-Cañero Dolores
Maimónides Biomedical Research Institute of Córdoba (IMIBIC), Córdoba, Spain.
Department of Genetics, University of Córdoba, Córdoba, Spain.
Front Plant Sci. 2019 Aug 30;10:1055. doi: 10.3389/fpls.2019.01055. eCollection 2019.
Base excision repair (BER) is a critical genome defense pathway that deals with a broad range of non-voluminous DNA lesions induced by endogenous or exogenous genotoxic agents. BER is a complex process initiated by the excision of the damaged base, proceeds through a sequence of reactions that generate various DNA intermediates, and culminates with restoration of the original DNA structure. BER has been extensively studied in microbial and animal systems, but knowledge in plants has lagged behind until recently. Results obtained so far indicate that plants share many BER factors with other organisms, but also possess some unique features and combinations. Plant BER plays an important role in preserving genome integrity through removal of damaged bases. However, it performs additional important functions, such as the replacement of the naturally modified base 5-methylcytosine with cytosine in a plant-specific pathway for active DNA demethylation.
碱基切除修复（BER）是一种关键的基因组防御途径，可处理由内源性或外源性基因毒性剂诱导的多种非大量DNA损伤。BER是一个复杂的过程，始于受损碱基的切除，通过一系列产生各种DNA中间体的反应进行，并最终恢复原始DNA结构。BER已在微生物和动物系统中得到广泛研究，但直到最近植物方面的知识仍较为滞后。目前获得的结果表明，植物与其他生物共享许多BER因子，但也具有一些独特的特征和组合。植物BER通过去除受损碱基在维持基因组完整性方面发挥重要作用。然而，它还执行其他重要功能，例如在植物特异性的主动DNA去甲基化途径中，用胞嘧啶取代天然修饰的碱基5-甲基胞嘧啶。
