Patra Jita, Sahoo Malaya K, Panda Brahma B
Genecology and Tissue Culture Laboratory, Department of Botany, Berhampur University, India.
Mutat Res. 2003 Jul 8;538(1-2):51-61. doi: 10.1016/s1383-5718(03)00085-8.
Induction and persistence of adaptive response by aluminium (Al), 1 or 10 microM, and paraquat (PQ), 5 or 10 microM, against genotoxicity of methyl mercuric chloride (MMCl), 1.26 microM, a standard environmental genotoxin, was investigated in root meristem cells of Allium cepa. Subsequently, three metabolic inhibitors, namely, 3-aminobezamide (3-AB, 10 or 100 microM), an inhibitor of poly(ADP-ribose) polymerase (PARP) implicated in DNA repair and/or apoptosis, cycloheximide (CH, 0.1 or 1 microM), an inhibitor of protein synthesis, and buthionine sulfoximine (BSO, 100 microM or 1mM), an inhibitor of glutathione synthesis were tested for their ability to prevent the adaptive response induced by conditioning doses of Al, 10 or 100 microM; and PQ, 5 or 100 microM, against MMCl-challenge, 1.26 or 100 microM, in root meristems of A. cepa or embryonic shoots of Hordeum vulgare, respectively. The findings demonstrated that once triggered, the Al- or PQ-adaptive response to MMCl could persist for at least 48h in root meristems of A. cepa. Furthermore, the adaptive response could effectively be prevented by 3-AB, to a lesser degree by CH, and the least by BSO, suggesting primarily the involvement of PARP and implicating DNA repair in the underlying mechanisms of adaptive response in plant cells in vivo.
研究了1或10微摩尔的铝（Al）以及5或10微摩尔的百草枯（PQ）对1.26微摩尔甲基汞氯化物（MMCl，一种标准环境基因毒素）遗传毒性的适应性反应的诱导和持续性，实验对象为洋葱根尖分生组织细胞。随后，测试了三种代谢抑制剂，即3-氨基苯甲酰胺（3-AB，10或100微摩尔），一种参与DNA修复和/或凋亡的聚（ADP-核糖）聚合酶（PARP）抑制剂；环己酰亚胺（CH，0.1或1微摩尔），一种蛋白质合成抑制剂；以及丁硫氨酸亚砜胺（BSO，100微摩尔或1毫摩尔），一种谷胱甘肽合成抑制剂，它们分别对10或100微摩尔的Al以及5或100微摩尔的PQ预处理剂量诱导的适应性反应的预防能力，这些预处理剂量的Al和PQ分别用于抵抗洋葱根尖分生组织中1.26或100微摩尔MMCl的挑战，以及大麦胚芽中100微摩尔MMCl的挑战。研究结果表明，一旦触发，Al或PQ对MMCl的适应性反应在洋葱根尖分生组织中可持续至少48小时。此外，3-AB能有效预防适应性反应，CH的预防效果次之，BSO的预防效果最差，这表明PARP主要参与其中，并暗示DNA修复在植物细胞体内适应性反应的潜在机制中发挥作用。
