纳米二氧化钛对拟南芥生长发育及基因组稳定性的影响

Effects of TiO_2-NPs on the Growth,Development and Genome Stability of Arabidopsis thaliana

[目的]利用3种拟南芥转基因报告系,研究纳米二氧化钛对拟南芥生长发育及基因组稳定性的影响。[方法]将拟南芥分别暴露于2种不同粒径的纳米二氧化钛材料中,检测其生长发育指标的变化,并进一步以DNA损伤修复同源重组频率和表观转录沉默基因(TGS)的激活为遗传学终点,检测纳米二氧化钛对拟南芥基因组稳定性的影响。[结果]在所使用的纳米二氧化钛材料浓度不影响拟南芥生长发育时,可以诱导拟南芥同源重组频率的增加以及同源重组相关基因表达的上调,同时能够激活受TGS调控的TGS-GUS基因、TSI以及180 bp。经ICP-MS分析,钛元素在地上部分的含量并无显著增加。[结论]考虑到纳米二氧化钛材料的局部暴露,推测纳米二氧化钛可能通过间接作用诱导植物基因组不稳定性。

[Objective] To study the effects of TiO_2-NPs on the genome stability and growth of Arabidopsis thaliana by using three kinds of transgenic lines of Arabidopsis thaliana. [Method]The model plants A. thaliana were exposed to culture medium contained two different sized TiO_2-NPs to study the effects on the growth and development of A. thaliana,and some genetic and epigenetic changes such as DNA homologous recombination（ HR） and the activation of transcriptional gene silencing（ TGS） were used to evaluate their genome stability. [Result]When the used TiO_2-NPs didn＇t affect the growth and development of A. thaliana,it increased the HR induction,up-regulated the expressions of HR-related genes,and activated the TGS loci（ TGS-GUS,TSI,and 180 bp）. ICP-MS analysis showed that the content of Ti in the aerial plants was not significantly increased. [Conclusion] Considering the localized exposures of the roots to TiO_2-NPs,it is speculated that the genome instability of the plants may be induced by TiO_2-NPs through an indirect pathway.