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以转Cu/Zn-SOD和APX基因及其非转基因甘薯进行盆栽试验,在甘薯块根膨大期进行正常供水(田间最大持水量的80%)、中度缺水(田间最大持水量的60%)和重度缺水(田间最大持水量的40%)3种水分处理,分别测定转基因植株和对照植株在薯块膨大期的第20天和第70天的抗氧化酶系统、可溶性糖含量、光合系统之间的差异,以及在不同水分胁迫处理下产量和水分利用效率之间的差异。以此研究外源基因的超表达是否可以提高甘薯的产量及水分利用效率。结果显示:(1)转基因甘薯(TS)的SOD、APX活性以及可溶性糖含量均高于非转基因对照株(NT),但POD活性低于NT;TS和NT植株的APX活性、可溶性糖含量、净光合速率以及蒸腾速率均随干旱胁迫加重呈递减趋势。(2)干旱胁迫70d时,TS和NT植株光合参数均较胁迫20d时降低,且TS和NT间的净光合速率没有明显差异。(3)TS和NT两株系的块根产量在中度胁迫下最高而在重度胁迫下最低,而TS具有较高的块根产量且在重度胁迫下产量降低幅度较小。(4)TS的气孔导度和蒸腾速率显著低于NT,且TS的水分利用效率较NT更高。研究表明,Cu/Zn-SOD和APX基因可以显著增加干旱胁迫下甘薯块根膨大期的SOD、APX活性和可溶性糖含量,提高其水分利用效率,从而减轻干旱胁迫对产量的影响。
Pot experiments were conducted with Cu / Zn-SOD and APX genes and their non-transgenic sweet potatoes. Normal water supply (80% of field maximum water holding capacity), moderate water deficit (60% of field maximum water holding capacity) And severe water deficit (40% of the maximum water holding capacity in the field). The antioxidant enzyme system, soluble sugar content, photosynthetic system and photosynthetic rate of transgenic and control plants on the 20th and 70th days of tuber expansion were measured respectively. And the differences between yield and water use efficiency under different water stress treatments. In order to study whether the exogenous gene overexpression can improve the sweet potato yield and water use efficiency. The results showed that: (1) The activities of SOD, APX and soluble sugar of transgenic sweet potato (TS) were higher than that of non-transgenic control (NT), but the activity of POD was lower than that of NT. APX activity, soluble sugar content, Net photosynthetic rate and transpiration rate decreased with the increase of drought stress. (2) At 70 d drought stress, the photosynthetic parameters of TS and NT plants were lower than those of 20 d stress, and there was no significant difference in net photosynthetic rate between TS and NT. (3) The root tuber yield of TS and NT lines were highest under moderate stress and lowest under severe stress, while TS had higher root yield and less yield under severe stress. (4) The stomatal conductance and transpiration rate of TS were significantly lower than those of NT, and TS had higher water use efficiency than NT. The results showed that Cu / Zn-SOD and APX genes could significantly increase the activities of SOD, APX and soluble sugar in sweet potato tuberous roots under drought stress, increase their water use efficiency, and alleviate the effects of drought stress on the yield.