Setlow B, Setlow P
Biochemistry Department, University of Connecticut Health Center, Farmington 06030, USA.
J Bacteriol. 1996 Jun;178(12):3486-95. doi: 10.1128/jb.178.12.3486-3495.1996.
Wet-heat or hydrogen peroxide treatment of wild-type Bacillus subtilis spores did not result in induction of lacZ fusions to three DNA repair-related genes (dinR, recA, and uvrC) during spore outgrowth. However, these genes were induced during outgrowth of wild-type spores treated with dry heat or UV. Wet-heat, desiccation, dry-heat, or UV treatment of spores lacking major DNA-binding proteins (termed alpha-beta- spores) also resulted in induction of the three DNA repair genes during spore outgrowth. Hydrogen peroxide treatment of alpha-beta-spores did not result in induction of dinR- and rerA-lacZ but did cause induction of uvrC-lacZ during spore outgrowth. Spores of a recA mutant were approximately twofold more UV sensitive and approximately ninefold more sensitive to dry heat than were wild-type spores but were no more sensitive to wet heat and hydrogen peroxide. In contrast, alpha-beta- recA spores were significantly more sensitive than were alpha-beta- spores to all four treatments, as well as to desiccation. Surprisingly, RecA levels were quite low in dormant spores, but RecA was synthesized during spore outgrowth. Taken together, these data (i) are consistent with previous suggestions that some treatments (dry heat and UV with wild-type spores; desiccation, dry and wet heat, hydrogen peroxide, and UV with alpha-beta- spores) that kill spores do so in large part by causing DNA damage and (ii) indicate that repair of DNA damage during spore outgrowth is an important component of spore resistance to a number of treatments, as has been shown previously for UV.
对野生型枯草芽孢杆菌孢子进行湿热或过氧化氢处理，在孢子萌发过程中未导致与三个DNA修复相关基因（dinR、recA和uvrC）的lacZ融合的诱导。然而，在用干热或紫外线处理野生型孢子的萌发过程中，这些基因被诱导。对缺乏主要DNA结合蛋白的孢子（称为α-β-孢子）进行湿热、干燥、干热或紫外线处理，在孢子萌发过程中也导致了这三个DNA修复基因的诱导。对α-β-孢子进行过氧化氢处理，在孢子萌发过程中未导致dinR-和rerA-lacZ的诱导，但确实导致了uvrC-lacZ的诱导。recA突变体的孢子对紫外线的敏感性比野生型孢子高约两倍，对干热的敏感性高约九倍，但对湿热和过氧化氢的敏感性并不更高。相比之下，α-β-recA孢子对所有四种处理以及干燥的敏感性都明显高于α-β-孢子。令人惊讶的是，RecA水平在休眠孢子中相当低，但在孢子萌发过程中会合成RecA。综上所述，这些数据（i）与先前的建议一致，即一些杀死孢子的处理（野生型孢子的干热和紫外线；α-β-孢子的干燥、干热和湿热、过氧化氢和紫外线）在很大程度上是通过造成DNA损伤来实现的，（ii）表明孢子萌发过程中DNA损伤的修复是孢子对多种处理产生抗性的一个重要组成部分，正如先前对紫外线的研究所示。
