过量表达菠菜SoCYP85A1基因增强烟草的耐盐性

Overexpression of SoCYP85A1 gene from Spinacia oleracea enhances high-salt tolerance in tobacco

本研究以转菠菜SoCYP85A1基因稳定表达的烟草植株为试验材料,检测了其耐盐性。利用NaCl模拟盐胁迫处理野生型和转基因烟草,结果表明:在高盐胁迫下,转基因烟草种子的发芽率显著高于野生型;二者的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性均增强,转基因植株的酶活性显著高于野生型;二者的脯氨酸(Pro)含量升高,并且转基因烟草积累量显著高于野生型,而转基因植株的丙二醛(MDA)含量增幅小于野生型;高盐处理后,野生型和转基因烟草的9个胁迫相关的基因表达倍数都增加,同野生型相比,转基因烟草的NtADC1、NtAPX、NtCAT、NtLEA5、NtGST、NtSOD和NtERD10C的表达量显著升高,而NtNCED1和Nt SAMDC基因的表达量变化不显著。本研究结果证实了过量表达SoCYP85A1基因能够通过增强烟草的抗氧化胁迫能力和调节胁迫相关基因的表达来提高烟草的耐盐性,为进一步阐明菠菜SoCYP85A1基因的耐盐机制奠定了理论基础。

Transgenic tobacco plants which stably overexpressed spinach SoCYP85A1 gene were used as plant materials in our study. Both wild types and transgenic lines were analyzed before and after high-salt stress. The results showed that the germination rate of transgenic plants was significantly higher than that of wild type. Under the treatment, activities of SOD, POD and CAT of the two types were increased, and the activities of the three enzymes in transgenic lines were notably enhanced compared with wild type. The contents of proline of the two types were raised, and proline accumulation of the transgenic type was much more than that of the wild type, while the MDA content of the transgenic type was less than that of the wild type. High-salt stress induced upregulation of nine stress-responsive genes at transcriptional level, among which, expressions of NtADC1, NtAPX, NtCAT, NtLEA5, NtGST, NtSOD and NtERDIOC were significantly increased in transgenic lines com- pared with wild types, with exception of NtNCED1 and NtSAMDC. The results indicated that overexpression of SoCYP85AI gene could improve the salt tolerance in tobacco via enhancing antioxidant capacity and regulating expressions of stress-responsive genes. This research laid the theoretical foundation for further exploration of salt tolerance mechanism of SoCYP85A1 in spanich.