过氧化氢酶2不参与调控拟南芥根部对镉胁迫的耐受性

Regulation of Tolerance to Cadmium Stress in Arabidopsis Roots without Catalase 2

[目的]探讨过氧化氢酶(CAT2)在拟南芥根部响应镉胁迫过程中对主根生长、活性氧积累以及生长素信号的影响。[方法]在1/2 MS固体培养基中加入不同浓度的镉处理拟南芥Col-0和CAT功能缺失突变体cat2幼苗。[结果]研究发现镉胁迫会抑制主根的根长,而cat2的根长的抑制率与Col-0并无明显差异。镉处理后Col-0和cat2根中CAT活性也不会发生显著变化。进一步比较Col-0和cat2根在镉胁迫下的活性氧的积累,两者活性氧增长率大致相同。最后检测DR5::N7-VENUS和cat2 DR5::N7-VENUS根中生长素的信号表达,发现镉胁迫对Col-0和cat2根中生长素的抑制率也没有差异。[结论]CAT2不参与调控拟南芥根部对镉胁迫的耐受性。

[Objective]Impact of catalase was discussed in the article based on the result of primary root length, reactive oxygen species accu-mulation and auxin signal in the primary root of Arabidopsis thliana responsive experiment under cadmium stress. [Method]Different concentra-tions of cadmium were added to 1 / 2 MS solid medium to treat Arabidopsis Col-0 and CAT2 loss-of-function mutant cat2 seedlings. [Result]Thestudy found that cadmium stress inhibited the root length of the main root, but the inhibition rate of cat2 root length was not significantly differ-ent from that of Col-0.However, the root length results between cat2 and Col-0 were no obvious differences. A similar conclusion also could bederived from the CAT activity in primary root after the cadmium stress treatment. Further comparing the accumulation of active oxygen in theroots of Col-0 and cat2 under the cadmium stress, the growth rate of their active oxygen is roughly the same. Finally, the signal expression ofauxin in Col-0 DR5：N7-VENUS and cat2 DR5：：N7-VENUS roots was detected. It was found that there was no difference in the inhibition rateof auxin in Col-0 and cat2 roots by cadmium stress. [Conclusion]CAT2 is not involved in the regulation of tolerance to cadmium stress in Ara-bidopsis roots.