Mechanism Of Various Cytoplasmic Male Sterility Associated Genes On Inhibition Of E.coli Growth

Cytoplasmic male sterility(CMS)is widespread phenomenon in plant.It is an ideal material for interaction research between nuclear and cytoplasmic,and also the basis of crop breeding for heterosis utilization.In most research show that CMS of plant is related to mitochondrial gene mutation.Technique bottleneck of activity mitochondrial system has seriously hindered in molecular mechanism research of CMS.Escherichia coli and mitochondrial share high similarity in DNA transcript and translation,also the respiratory chain of plasma membrane are highly conserved.In this paper,three kinds of types of rice CMS gene(orf79,WA352,orfH79)were transformed into Escherichia coli.Research on the effect of three CMS gene expression strain growth and oxidative respiration,to reveal the molecular mechanism of rice CMS.The major results are shown as follows:1.Three CMS gene expression has strongly inhibited of Escherichia coli growth.Conjunction with live colony count,we found that the levels of inhibition is orfH79> orf7 > WA352.2.Three CMS gene expression protein(ORF79 ? ORFH79 ? WA352),all accumulates in the plasma membrane of Escherichia coli.3.Delected content of ROS and ATP in the three CMS gene expression strain and control strain,we found that CMS gene expression caused increased of ROS and decrease of ATP with different levels.The degree of increased of ROS is orfH79> orf79> WA352 and degree of decreased of ATP is orfH79> orf79> WA352.4.We select three key enzyme in oxidation respiratory(pyruvate kinase,citrate synthase,?-ketoglutarate dehydrogenase)for activity assay.The results show that CMS geneexpressing has inhibited the vitality of enzyme withvarying degrees.Degree of inhibition of PK activity is orfH79> orf79> WA352 and degree of inhibition of ?-KGDH activity is orfH79> orf79> WA352;orfH79 and orf79 has no significant difference in the degree of inhibition CS activity,but are larger than WA352.These results indicate that CMS gene expression protein cause varying degrees of damage in oxidation respiratory chain of Escherichia coli.And lead to unusual outbreaks of ROS,also lack of ATP,thus cause difference inhibition of Escherichia coli growth.This paper argues that the damage model in bacterial of CMS gene expression protein has similarity expression pattern in mitochondria.We can study the molecular mechanism of various CMS genes in rice through Escherichia coli system.