过量表达番茄类囊体膜抗坏血酸过氧化物酶基因（StAPX）提高了烟草种苗的抗氧化能力

为了探讨叶绿体类囊体膜抗坏血酸过氧化物酶（tAPX）与其抗氧化性的关系，从番茄叶片中分离了叶绿体类囊体膜抗坏血酸过氧化物酶基因（StA跚并转入到烟草中。以野生型（WT）、转正义StAPX烟草株系T3-3和T3-6为试材，测定了外源过氧化氢诱导的氧化胁迫条件下APX酶活性、过氧化氢酶（CAT）活性、过氧化氢（H2O2）含量、叶绿素荧光参数及叶绿素含量等。Northern杂交显示StAPX因的表达受外源H2O2氧化胁迫的诱导。氧化胁迫下转基因烟草的APX酶活性和清除H2O2的能力都显著高于野生型，并且转基因烟草比野生型具有更高的PSII最大光化学效率及叶绿素含量。结果表明，．刚尸舶勺过量表达有助于提高外源H2O2诱导的转基因烟草的抗氧化能力。

Tobacco Seedlings Overexpressing StAPX Enhanced Resistance to Oxidative Stress

In order to investigate the relationship between thylakoid-bound ascorbate peroxidase(tAPX) and the resistance to oxidative stress,tomato tAPX gene(StAPX) was introduced into tobacco.Wild type(WT),sense-transgenic lines(T3-3 and T3-6) of tobacco were used to measure activities of APX and catalase(CAT),contents of hydrogen peroxide(H2O2),contents of chlorophyll and chorophyll fluorescence parameters under oxidative stress.Northern blot analysis confirmed that the expression of StAPX was induced by exterior H...