干旱胁迫下CO2浓度升高对转StAPX番茄植株耐旱能力的影响

在干旱胁迫伴随大气CO2浓度以及升高的CO2浓度（加倍）条件下，以过量表达番茄类囊体膜抗坏血酸过氧化物酶基因（StAPX）的转基因番茄为试材，探明干旱胁迫TCO2浓度升高对转基因及其野生型番茄植株清除活性氧及耐旱能力的影响。结果表明：升高的CO2浓度明显增加了干旱胁迫下植物的光合水平；升高的CO2浓度明显降低了干旱导致的植物体内H2O2．和O2的积累，影响了干旱胁迫下番茄植株的水．水循环系统的活性氧清除酶活性和小分子抗氧化物质含量；干旱胁迫下即使伴随升高的CO2浓度，测试番茄植株体内的渗透调节物质含量变化也不太明显；升高的CO2浓度明显降低了干旱胁迫下的植物细胞膜伤害程度；干旱胁迫下，升高的CO2浓度对转基因番茄株系比对野生型植株的影响更加明显。结果证明干旱逆境下，升高的CO2浓度能够在一定程度上进一步提高转基因番茄植株的耐旱性。

Effects of Elevated CO2 Concentration on Drought Tolerance in Transgenic To- mato Plants under Drought Stress

In this study, transgenic tomato plants over-expression of StAPX were tested under drought stress, companied with atmosphere and elevated （doubled） CO2 concentration. The influences of elevated CO2 concen- tration on the ROS-scavenging ability and the drought tolerance in transgenic and wild tomato plants under drought stress were studied. It was found that elevated CO2 concentration increased the photosynthetic level in plants under drought stresses. Elevated CO2 concentration reduced the accumulation of H202 and O2, and influ- enced antioxidant enzyme activities of water-water cycle system and small molecule antioxidant substance con- tents in tomato plants under drought stress conditions. Osmotic adjustment substances contents in tested plants changed little even at elevated CO2 concentration under drought stresses. Elevated CO2 concentration reduced the damage of cell membrane under drought stresses. The influence degree of elevated CO2 concentration on transgenic lines was more outstanding than that in wild tomato plants. The results showed that elevated CO2 concentration can increase the tolerance oftransgenic tomato plants to drought stress to some extent.