Cloning And Function Analysis Of Pseudouridine Synthase Genes TCD3 Associated With Rice Chloroplast Development(Oryza Sativa L.)

The normal development of higher plant chloroplasts and the normal synthesis of chlorophyll are controled by nuclear and chloroplast genes.These genes mutations can lead to chloroplast developmental defect.Experimental materials of this study derived fromjaponica variety Jiahua No.1 treated by 60 Co γ-rays for the temperature sensitive yellow green mutant tcd3.Through analyzing the phenotype,map-based cloning and bioinformatics analysis and related functional analysis,we draw the following conclusions:1.Through analyzing the phenotype of the two mutations,we found that under the condition of the environment temperature of 20℃,tcd3 is yellow green phenotype,but under the condition of the environment temperature of 32 ℃,the phenotype of tcd3 is no obvious difference compared with wild type Jiahua No.1.2.By analyzing the photosynthetic pigment content of 3-leaf-stage seedlings grown at 20 ℃ and 32 ℃ showing that tcd3 phenotype was associated with the accumulation of photosynthetic pigment.At 20°C,the photosynthetic pigment content of tcd3 was significantly decreased compared with that of wild type.However,the pigment levels were similar to WT plants at 32°C.3.Genetic analysis of F2 generation of mutant tcd3 revealed that the mutant was a recessive nuclear gene.4.Using map-based cloning technology the mutant gene was localized between the In Del marker ID2917 and ID2738 on chromosome third,with physical distant of 179 kb.Sequencing analysis showed that encoding pseudouridine synthase family protein gene of candidate genes of the range.Sequence alignments with WT genes revealed that there was a base G substitut and five base TCTTG deletion on the fifth exon of LOC＿Os3g05806,which will lead to early termination of protein translation.5.Conservative analysis on amino acid sequence encoding by TCD3 revealed that it shares high sequence similarity to different higher plants.Further analysis of the homologous evolution relationship with more species,showing that TCD3 is more conserved in monocotyledons,rather than dicotyledons.6.For tcd3 mutant under the condition of high and low temperature and chlorophyll synthesis,photosynthesis,photosynthesis,chloroplast development related gene transcription level of TCD3 gene analysis showed that may affect the early development of chloroplasts,especially a greater impact on the second and third stages,thus leading to the slow development of the chloroplast,chlorophyll accumulation and photosynthesis are affected,so that the mutant showed chlorosis phenotypeThis study provides a theoretical basis for the study of gene TCD3,and provides some new ideas for the functional analysis of TCD3 and the mechanism of chloroplast development and regulation.