An Initial Function Analysis Of The PPR Gene OsPGL1 In Rice(Oryza Sativa L.)

PPR(Pentatricopeptide repeats)protein,also known as triangular pentapeptide repeat protein,is a new gene family found in the Arabidopsis thaliana genome sequencing,one of the largest protein families of terrestrial plants,and more than 450 members in Arabidopsis,and 477 members of rice.The typical PPR protein contains 2 to 27 PPR motifs with 35 amino acid residues,and N-terimimal contain organelle localization sequences.The C-terminal has three selectable non-PPR domains:E,E +,DYW.The PPR family in the plant is composed of two subfamilies of P and PLS.Most of the P subfamilies contain only the P motif;the PLS subfamily contains the characteristic triplets of the P,L,S motifs,which can be divided into PLS,E and DYW three groups according to the C-terminal.They bind to one or more organelle transcripts,editing,splicing,stabilize and translate the expression of RNA,and play a variety of functions during plant growth and development.In this study we will introduce a rice PPR gene Os12g06650,sequence analysis found that this gene belongs to the DYW-type PPR gene,the subcellular localization results showed that the gene was located in the mitochondria and chloroplast.The expression pattern of qRT-PCR suggested Os12g06650 in the root,stem,leaf and spikelet and peak in the leaf.We used antisense strand interference technique constructed the transgene-positive material which was pale green compared with wild-type zhonghua 11,so it was named Ospgll(pale green leave).The cytologic observation showed that the chloroplast was degraded and the structure was disordered in the interfering material.Compared with the wild type,the chlorophyll content was significantly reduced,but was increased in the overexpressed paints;Further studies have shown that the nucleotides of the 878th locus of the chloroplast gene ndhD are T in the wild-type zhonghua 11 and C in the interfering material,the amino acid is changed from leucine to serine,and in the mitochondrial gene ccmFc the nucleotide at position 543 is T in the wild type and C in the interfering material,which is at the third position of the triplet codon.According to the codon degeneracy,the amino acid encoded by this locus does not change.In this study,we found that the gene was involved in mitochondrial and chloroplast gene RNA editing.In order to further verify the reliability of the results,we constructed the knockout material by CRISPR/CAS9 technique.Two of the positive plants in the transgenic plants had nucleotides deletion in the target region,the deletion of 41 bp at 288-328 and the single base deletion at position 530,respectively,because of its heterozygous T0 generation,so the phenotype has not yet seen leaf color defects,we will do the further study of genetic analysis and phenotype research.