Analysis of the Redox Regulation System and its Application of Molecular breeding in Higher Plants

1)H_2O_2积累和光合电子传递的氧化还原状态对胞质抗坏血酸过氧化物酶（cAPX）表达的影响在叶绿体中表达过氧化氢酶和类囊体膜结合型抗坏血酸过氧化物酶（APX）的转基因烟草中，研究了光氧化应激条件下PET细胞内H_2O_2积累或氧化还原状态改变与cAPX诱导的关系。这些结果表明，cAPX表达的诱导是由PET中的氧化还原变化引起的，可能是PQ库在早期和之后细胞内H_2O_2水平的增加。我们研究了不同叶龄叶片中各种抗氧化剂和抗氧化酶水平的差异。数据表明，抗氧化剂和抗氧化酶水平的下降是由于叶片中抗氧化剂和抗氧化酶水平的下降。 关于我们 （2）AOS信号分子对许多生理过程的调控，包括对环境胁迫反应的调控我们以转基因烟草BY-2细胞系cAPX-S2和cAPX-S3为材料，研究了cAPX活性降低对烟草BY-2细胞的影响。有趣的是，APX抑制的细胞对环境胁迫（如高温和盐度）表现出不同的反应和耐受性。抑制性消减杂交显示，一些热和盐胁迫诱导基因上调cAPX-S3细胞。HSP 70、DnaJ样蛋白和紫色酸性磷酸酶等基因是组成型诱导的基因。3）转氧化还原调节基因植物的分子育种为了鉴定高等植物中氧化还原调节基因，我们试图获得表达氧化还原调节因子的转基因植物。少

1)The influence of H_2O_2 accumulation and redox status of the photosynthetic electron transport on the expression of cytosolic ascorbate peroxidase (cAPX).Transgenic tobacco plants expressing catalase and thylakoid-membrane bound APX in chloroplasts, both of which had increased tolerance to photooxidative stress, were utilized for evaluation of the relationship between H_2O_2 accumulation or change of redox status of the PET and cAPX induction under photooxidative stress condition. These results suggest that the induction of cAPX expression is caused by a redox change in the PET, probable PQ pool at an early stage and-thereafter by an increase in the cellular H_2O_2 level.Next, to clarify the mechanism of the decline in oxidative stress tolerance of leaves during the course of senescence, we studied the differences in the levels of various antioxidants and antioxidant enzymes in leaves of different ages.The data suggest that the decline in the levels of antioxidants and antioxidant en … More zymes associated with leaf senescence lead to lower photooxidative-stress tolerance, which might in turn accelerate the propagation of senescence.2)The effect of AOS, signal molecules on the regulation of many physiological processes, including environmental stress responses.We investigated the effect of lowered cAPX activity in transgenic tobacco BY-2 cells, using two transformed BY-2 cell lines, cAPX-S2 and cAPX-S3. Interestingly, the APX-suppressed cells showed different responses and tolerances to environmental stresses, such as heat and salinity. Suppression subtractive hybridization revealed that several heat and salt-stress inducible genes were upregulated in cAPX-S3 cells. HSP70, DnaJ-like protein and purple acid phosphatase were among the constitutively induced genes.3)Molecular breeding of transgenic plants introducing the genes involved in the redox regulation.To identify the genes involved in the the redox regulation in higher plants, we are trying to generate transgenic plants expressing a redox regulatory factor. Less