严重土壤干旱后复水条件下转基因甘薯的光合响应特性

采用盆栽试验在重度干旱胁迫（土壤田间持水量的35%~40%及复水条件下,对同时转入Cu/Zn SOD和APX 基因的甘薯和未转基因对照植株的光合响应特性进行研究结果表明,干旱胁迫及复水过程中转基因和未转基因植株光响应曲线的变化趋势基本一致采用非直角双曲线模型拟合良好转基因TS和未转基因甘薯NS的最大净光合速率Pmax光饱和点LSP和表观量子效率（渍暗呼吸速率（Rd）在干旱胁迫下均明显降低复水后又逐渐增加但与NS 植株相比TS 植株在胁迫条件下降低的幅度较小，而在复水过程中恢复得也更快,反映出转入的抗氧化酶基因提高了甘薯在干旱胁迫条件下的光合能力及修复能力,增强了对干旱胁迫的适应性TS 和NS 植株的光补偿点（LCP）在干旱胁迫下显著提高,但TS 植株上升的幅度比NS 植株小复水过程中修复得也更快,表明转基因甘薯增强了对光环境的适应性.

Photosynthetic characteristics of rewetted transgenic sweetpotato after severe drought condition and rewetted

A comparative study on photosynthetic characteristics between the genetic modified sweet potato transferredwith the Cu/Zn SOD and APX genes (TS) and non-GM sweet potato (NS) was carried out with pot experiments. Threecontrols, namely the favorable soil moisture (75%~80% of field water capacity, FWC), the moderate drought (60%~65% ofFWC) and the severe drought (35%~40% of FWC) groups were used. The Result showed that light response curves of theTS and NS had no significant difference under these three soil moisture conditions. The fitting result showed goodperformance by non-rectangular hyperbolic model. The net photosynthetic rate (Pmax), light saturation point (LSP) andapparent quantum efficiency , dark respiration rate (Rd) of both TS and NS plants decreased significantly under droughtconditions and then continually increased. However, the decrease of TS plant was less than NS plant under stress conditionand the recovering was quicker. These results indicated that overexpressing antioxidant enzyme genes enhanced sweetpotato photosynthetic capacity, adaptability of drought stress and recovery capability. Light compensation point (LCP) ofsweet potato increased significantly under drought stress, but the rise in TS plants was less than NS control. These resultsshowed that transgenic genes to sweet potato enhanced its light environmental adaptability