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为研究枇杷(Eriobotrya japonica Lindl.)脱水素基因(Ej DHN5)在枇杷抗低温胁迫中的功能,将其在烟草中进行过量表达,其中表达水平比较高的两个株系L24和L26被用来进行功能研究。野生型和转基因烟草苗分别用0、2、4和8μmol·L~(-1)的甲基紫精(Methyl viologen,自由基发生剂)处理并进行光照培养,结果显示,4和8μmol·L~(-1)甲基紫精处理使野生型烟草苗存活率分别下降到73.6%和56.9%,光系统Ⅱ(PSⅡ)活性显著降低,而转基因苗的存活率仍维持在100%,PSⅡ活性明显高于野生型。对六叶期烟草的叶盘进行甲基紫精处理,野生型烟草叶盘的叶绿素含量显著低于转基因株系,而活性氧含量和MDA含量明显高于转基因株系。对野生型和转基因烟草苗进行低温处理,转基因株系生长状况明显优于野生型,活性氧含量低于野生型,膜质过氧化程度轻于野生型。这些结果表明,过量表达EjDHN5能提高烟草的抗氧化胁迫和抗低温胁迫能力,推测EjDHN5在提高枇杷抗低温能力方面起着重要作用可能与其能提高抗氧化胁迫能力有关。
To study the function of Ej DHN5 in the anti-low temperature stress of Eriobotrya japonica Lindl, it was overexpressed in tobacco, and two lines, L24 and L26, with relatively high expression levels were used Conduct functional studies. Wild-type and transgenic tobacco plants were treated with 0, 2, 4 and 8 μmol·L -1 methyl viologen (free radical generating agent) respectively and cultured under light. The results showed that 4 and 8 μmol·L ~ (-1) methylvimentin decreased the viability of wild type tobacco seedlings to 73.6% and 56.9%, respectively, while the activity of PSⅡ decreased significantly while the survival rate of transgenic seedlings remained at 100%. The activity of PSⅡ Significantly higher than the wild type. The leaf disks of six-leaf tobacco were treated with methyl viologen. The content of chlorophyll in leaves of wild-type tobacco leaves was significantly lower than that of the transgenic lines, but the content of reactive oxygen species and MDA in the leaves of the tobacco were significantly higher than those in the transgenic lines. Under the condition of low temperature treatment of wild and transgenic tobacco plants, the growth of transgenic lines was significantly better than that of wild type and the content of reactive oxygen species was lower than that of wild type. The degree of membrance peroxidation was lighter than that of wild type. These results indicate that overexpression of EjDHN5 can enhance the antioxidant and anti-chilling tolerance of tobacco, suggesting that EjDHN5 may play an important role in enhancing the anti-hypothermia ability of loquat possibly related to its ability of increasing antioxidant stress.