Genetic Analysis And Map-Based Cloning Of Seedling Lethal Mutant Abl25 And Ygll In Rice(Oryza Sativa L.)

With the rapid and violent development of the modern plant molecular biology technology, as a monocotyledonous,rice research is becomming more and more favorred by the people.Chloroplast development need the regulation of the nuclear genes and plastid genes together, mutations of any gene can lead to loss of function,which will affect the growth and development of the chloroplast, or even alternative genetic modification, can also lead to the weakening or loss in late transcription and expression function, As a result,the plant leaf color swifts.We got a rice albino mutant abl25 and green-yellow mutant ygll by physical mutagenesis, then we analysed their traits, genetic level, and the related functions, the obtain result and conclusion were discribed as follow:1.Compared with the wild type jiahua No.1, the abl25 mutant type showed albino phenotype, ygll presented yellow green phenotype no matter in temperature25 or 32, they all died after 3 leaf stage gradually.And there were light and pigment content(chlorophyll, chlorophyll a and chlorophyll b) levels in each of them, there is obvious defects in the chloroplast structure.2. the genetic analysis of F2 population derived from the cross between the Guang Zhan 63 s and mutant abl25 / ygll, showed that the two mutants were controlled by one pair of recessive nuclear genes mutant.3.Map-based cloning of the two mutant were conducted,respectively to locate them in rice chromosome 2(abl25) and 8(ygll),semi-quantitative RT-PCR and quantitative RT-PCR analysis of the candidate genes wthin predicted area,it revealed that the exprension of LOC_Os08g37700 in RNA level raised in a big scopes.We Sequenced it, but found no differences,so trait of ygll was suspected to be caused by methylation.4. Quantitative RT-PCR of the genes related to chloroplast development of ygll mutant, showed that the NEP,PEP-dependent genes had a down-up-regulation and the mutant ygll is great possible to explain the death of mutant genes for chlorophyll synthesis, chloroplast development and regulation of photosynthesis.5.Inhibition of positive and negative experimentof YGLL methylation make us initially thought that it’s death is caused by epigenetics, the possibility of a gene has a lot to be methylated.In conclusion, the aim of this study is to provide new theoretical basis andreference for the later chloroplast development mechanism in regulating gene expression and its related research.