Study of interaction mechanisms among environmental mutagens with Tradescantia stamen hairs

以紫露草无性系BNL 4430为材料，在营养液循环(NSC)培养箱中，以雄蕊毛体细胞粉红色突变率为指标，研究了不同诱变剂之间的相互作用机理。在已研究的5种单功能烷基化剂中，甲基磺酸甲酯(MMS)、硫酸二甲酯(DMS)、甲磺酸乙酯(EMS)和N-乙基-N-亚硝脲(ENU)对X射线有明显的协同作用，而N-甲基-N-亚硝脲(MNU)对X射线的作用仅表现为相加效应。MMS、DMS、EMS、MNU和ENU的诱变协同作用和诱变模式与其Swain-Scott底物常数不一致(S分别为0.88、0.86、0.67、0.42和0.26)。在这项研究中，研究了另一种单官能团烷基化试剂--硫酸二乙酯(DES)，发现它与X射线有协同作用，但协同模式也不符合…更多的是具有S的价值。此外，MNU和EMS之间的作用只是相加作用，不同于先前证实的MMS和EMS之间明显的协同作用。另一方面，已研究的三种诱变剂马来酰肼(MH)、邻苯二胺(PDA)和N-亚硝酸二甲胺(DMN)在处理前的X射线照射下都表现出诱变协同作用，而处理后的X射线处理后都表现出拮抗作用，过氧化物酶活性在前两种情况下分别增加和降低，证明了这种酶参与了激活它们的作用。在DMN、PDA和MH处理过程中，这些诱变剂之间的差异表现为协同、相加和拮抗作用。在本研究中，1，2-二溴乙烷(EDB)也是一种双官能团烷基化试剂，在处理EDB的过程中，它在X射线照射下表现出明显的协同作用，但MH和EMS总是表现出拮抗作用。早期和现在的结果使人们可以认为，烷基化试剂、X射线以及被激活后成为诱变剂的诱变剂，当它们至少具有部分共同的作用机制，如断裂DNA链或染色体时，就表现出诱变协同作用，而当它们没有任何共同的作用机制时，就会出现相加效应。另一方面，对于原诱变剂，当它们被禁止激活为诱变剂时，就会出现拮抗效应。较少

Interaction mechanisms among different mutagens were studied based on somatic pink mutation frequencies in the stamen hairs, by cultivating a large number of young Inflorescence-bearing shoots with roots of Tradescantia clone BNL 4430 in a nutrient solution circulating (NSC) growth chamber.Four out of the five monofunctional alkylating agents ever studied, i.e., methyl methanesulfonate (MMS), dimethyl sulfate (DMS), ethyl methanesulfonate (EMS) and N-ethyl-N-nitrosourea (ENU) had shown clear synergistic effects with X rays, whereas N-methyl-N-nitrosourea (MNU) had shown merely additive effects with X rays, and their mutagenic synergisms and the patterns had not coincided with their Swain-Scott substrate constnats (s=0.88, 0.86, 0.67, 0.42 and 0.26 for MMS, DMS, EMS, MNU and ENU, respectively). In this study, diethyl sulfate (DES), another monofunctional alkylating agent, was studied and was found to act synergistically with X rays, but the pattern of the synergism also did not coincide … More with the s value. Besides this, MNU and EMS was found to act merely additively, differing from the clear synergistic effects between MMS and EMS which had been confirmed earlier.On the other hand, three promutagens ever studied, maleic hydrazide (MH), o-phenylenediamine (PDA) and N-nitrosodimethylamine (DMN), all had shown mutagenic synergisms when exposed to X rays before the treatments with these promutagens, while all had shown antagonistic effects when exposed to X rays after treating with these promutagens, peroxidase activity increasing and decreasing in the former and the latter cases, respectively, proving the involvement of this enzyme in activating them. Differences among these promutagens had been synergistic, additive and antagonistic effects observed when exposed to X rays during the treatments with DMN, PDA and MH, respectively. In this study, another promutagen, 1,2-dibromoethane (EDB,) which is also a bifunctional alkylating agent, was found to show clear synergisms when exposed to X rays during treating with EDB, but MH and EMS always showed antagonistic effects.Earlier and the present results make it possible to consider that alkylating agents, X rays, and also promutagens Which become mutagens after being activated show mutagenic synergisms when they have at least partly common action mechanisms such as breaking DNA strands or chromosomes, while additive effects appear when they do not have any common action mechanisms. As for promutagens, on the other hand, antagonistic effects appear when their activations into mutagens are prohibited. Less