PPF1 is a vegetative growth related gene that encodes a putative membrane protein having high homology with Arabidopsis chloroplast thylakoid protein ALB3. Immunoelectron microscopic assay showed that PPF1 was mainly ...PPF1 is a vegetative growth related gene that encodes a putative membrane protein having high homology with Arabidopsis chloroplast thylakoid protein ALB3. Immunoelectron microscopic assay showed that PPF1 was mainly localized in the thylakold membrane and was highly expressed in well-developed chloroplasts of short day (SD) grown G2 pea while having a very low abundance in chloroplasts of long day (LD) grown plants two weeks after flowering. Comparison of the leaf senescence processes in transgenic Arabidopsis and wild type plants revealed that overexpression of PPF1 delayed leaf senescence, while the depression of its Arabidopsts homologue (ALB3) with PPF1 antisense mRNA accelerated leaf senescence obviously. Ultrastructural analysis of transgenic Arabidopsis plants showed that when PPF1 was overexpressed in Arabidopsis, the chloroplasts were bigger and had much more grana and stroma thylakoid membranes than those of wild type plants. On the contrary, when PPF1 was expressed in antisense orientation to reduce the level of PPF1 homologue in Arabidopsis, the transgenic plants had smaller chloroplasts With less grana. and poorly developed thylakoid membrane systems. These results suggested that the developmental status of chloroplasts was positively correlated with the level of PPF1 or its Arabidopsts homologue, ALB3. Our results suggested that PPF1 gene might regulate plant development by controlling chloroplast development.展开更多
研究空间结构中悬臂梁的主动振动控制。首先使用PPF(Positive Position Feedback)的主动振动控制方法,得到和一般负反馈相比相对优化的脉冲响应,再利用结构频率与特征方程根的关系进行最优化参数选取,最后进行仿真。仿真结果表明基于PP...研究空间结构中悬臂梁的主动振动控制。首先使用PPF(Positive Position Feedback)的主动振动控制方法,得到和一般负反馈相比相对优化的脉冲响应,再利用结构频率与特征方程根的关系进行最优化参数选取,最后进行仿真。仿真结果表明基于PPF方法主动振动控制能够很好地实现对悬臂梁结构的振动控制。展开更多
文摘PPF1 is a vegetative growth related gene that encodes a putative membrane protein having high homology with Arabidopsis chloroplast thylakoid protein ALB3. Immunoelectron microscopic assay showed that PPF1 was mainly localized in the thylakold membrane and was highly expressed in well-developed chloroplasts of short day (SD) grown G2 pea while having a very low abundance in chloroplasts of long day (LD) grown plants two weeks after flowering. Comparison of the leaf senescence processes in transgenic Arabidopsis and wild type plants revealed that overexpression of PPF1 delayed leaf senescence, while the depression of its Arabidopsts homologue (ALB3) with PPF1 antisense mRNA accelerated leaf senescence obviously. Ultrastructural analysis of transgenic Arabidopsis plants showed that when PPF1 was overexpressed in Arabidopsis, the chloroplasts were bigger and had much more grana and stroma thylakoid membranes than those of wild type plants. On the contrary, when PPF1 was expressed in antisense orientation to reduce the level of PPF1 homologue in Arabidopsis, the transgenic plants had smaller chloroplasts With less grana. and poorly developed thylakoid membrane systems. These results suggested that the developmental status of chloroplasts was positively correlated with the level of PPF1 or its Arabidopsts homologue, ALB3. Our results suggested that PPF1 gene might regulate plant development by controlling chloroplast development.
文摘研究空间结构中悬臂梁的主动振动控制。首先使用PPF(Positive Position Feedback)的主动振动控制方法,得到和一般负反馈相比相对优化的脉冲响应,再利用结构频率与特征方程根的关系进行最优化参数选取,最后进行仿真。仿真结果表明基于PPF方法主动振动控制能够很好地实现对悬臂梁结构的振动控制。
