低温胁迫下交替氧化酶在拟南芥植株幼根生长中的作用

The role of alternative oxidase in the regulating growth of the primary root of Arabidopsis seedlings under low temperature

以交替氧化酶(Alternative Oxidase;AOX)基因反义抑制突变体(AS-12)、超表达突变体(XX-2)及野生型(WT)拟南芥(Arabidopsis thaliana)植株为实验材料,研究了低温胁迫(4℃)对3种基因型拟南芥植株主根的长度、生长速率以及细胞活力的影响.结果显示:在22℃生长条件下,3种植株主根的长度、生长速率及细胞活力均无显著性差异.与在22℃下相比,低温胁迫明显降低了3种植株主根的长度、生长速率和细胞活力;在低温胁迫下,XX-2植株的主根明显长于AS-12和WT,其主根的生长速率和细胞活力也明显高于AS-12和WT.上述结果表明,低温胁迫下拟南芥主根的生长及其细胞活力可能受到了AOX基因的调节.讨论了AOX在低温胁迫条件下对植物幼根生长作用的可能的内在机理.

The effects of low temperature on the length,growth rate,and cell viability of the primary roots of Arabidopsis seedlings were investigated using the AOX （alternative oxidase） anti-sense line （AS-12）,AOX overexpression line （XX-2）,and wild-type （WT） plants.The results showed that there was no obvious difference in the length,growth rate,and cell viability of the primary roots among these three kinds of Arabidopsis plants grown under 22 ℃.Compared with the growth under 22 ℃,these three kinds of Arabidopsis plants grown under low temperature （4 ℃） had lower levels of the length,growth rate,and cell viability of the the primary roots.Under the low temperature,however,the primary roots of XX-2 had higher levels of the length,growth rate,and cell viability than either AS-12 or WT.These observations suggested that mitochondrial AOX could play a role in mediating primary root growth under low temperature stress.The possible mechanism was also discussed in this paper.