转哺乳动物cyp2e1基因矮牵牛耐甲醛胁迫的生理机制

The Physiological Mechanism of Petunia hybrida Harboring Mammalian cyp2e1 Gene Improving Resistance to Formaldehyde

细胞色素P450 CYP2E1酶主要存在于哺乳动物肝细胞中,在代谢异源有机物方面起着重要作用。前期研究发现,转cyp2e1矮牵牛显著提高了对甲醛的抗性。以转cyp2e1矮牵牛为试验材料,分析其对甲醛胁迫响应的相关生理指标。结果显示,在甲醛胁迫下,转cyp2e1矮牵牛细胞中的MDA含量低于转gus和野生型矮牵牛,SOD和POD活性均高于转gus和野生型,乙醇脱氢酶(ADH)活性稍有增强,且消耗更多的谷胱甘肽。此外,在甲醛胁迫下,转cyp2e1矮牵牛的IAA、ZRs和ABA含量呈现下降而GA含量呈现上升趋势;但转gus和野生型矮牵牛IAA、ZRs和ABA含量呈现上升而GA含量呈现下降趋势。转cyp2e1矮牵牛在含有50 mg·L-1甲醛的处理液中孵育72 h后,处理液中甲醛含量接近为0;而转gus和野生型处理液中仍有近50%的甲醛。

The cytochrome P450 CYP2E1 enzyme mainly exists in mammalian liver cells. It plays an important role in metabolism of heterologous organics. Precious research has shown that cyp2e1 transgenic Petunia hybrida significantly improved the resistance to formaldehyde. In the paper,the various physiological characteristics of cyp2e1 transgene,gus transgene and wild-type(non-transgenic)P. hybrida were analyzed under formaldehyde stress. The results show that malondialdehyde(MDA)content of cyp2e1 transgenic P. hybrida was lower than those of gus transgene and wild-type P. hybrida under formaldehyde stress,while both of superoxide dismutase(SOD)and peroxidase(POD)enzyme activity were higher,alcohol dehydrogenase(ADH)activity slightly enhanced and more glutathione was metabolized. In addition,levels of IAA,ZRs and ABA in cyp2e1 transgenic P. hybrida decreased under formaldehyde stress,but level of GA increased. However,levels of IAA,ZRs and ABA in gus transgene and wild type P. hybrida were increased but level of GA was declined. When the cyp2e1 transgenic P. hybrida was incubated in liquid medium plus 50 mg · L-1 formaldehyde for 72 h,the formaldehyde content in medium was decrease to zero,while those with gus transgene and wild-type P. hybrida were still nearly half of formaldehyde content.