Haplotype Analysis Of The Maize Phosphate Pyruvate Dikinase（PPDK） Gene C₄PPDKZm1 Promoter Region

Maize is the most produced cereal crop worldwide with highest productivity per unit area. Many factors affect its productivity, among them the most important is Photosynthetic utilization ratio. Breeding high yield varieties with high light efficiency is a key concern of breeders. Understanding the influence of molecular biological characteristics of maize photosynthesis will help the breeders to breed higher photosynthetic efficiency varieties.Pyruvate phosphate dkinase (PPDK) a transcript of C4PPDKZml gene, expressed in the leaves directly affects the photosynthetic efficiency of maize plants. Understanding the effect of variation in DNA sequence at specific loci on the gene expression will provide theoretical and technical basis to breeders to breed the high photosynthetic efficiency maize varieties. This study takes the promoter sequence of C4PPDKZml for research objects to discover the mutation points(SNPs) that have significant effects on expression of the gene. The main results of the study are as follows:1. Analysis of the expression pattern of C4PPDKZm1 gene. Found significant differences in gene C4PPDKZm1 expression in different parts of maize plant. In the leaves it was highest and in the ear it was minimum. During the vegetative growth stages, the expression of gene followed increasing trend from seedling to booting.. Reproductive growth stage also followed a sample tendency from pollination to 30 days. Gene expression also varied with day light with maximum expression in the middle of day.2. Comparison of promoter sequence of C4PPDKZml gene of 148 maize genotypes. The promoter sequence in the 148 genotypes C4PPDKZml gene were amplified after do re sequencing. The sequencing results were compared with the standard software and the confirmed by manual correction, Worked out the correlation analysis of the 148 genotype’s C4PPDKZm1 gene expression and grain weight.I. The expression of the gene by the whole genome association analysis showed that the gene was located on sixth and seventh chromosome. The results obtained on chromosome sixth were consistent with the previous results;II. On the gene expression and promoter sequences as candidate gene association analysis showed that, a total of 12 SNPs were mapped to,4 single base mutations and 8 nucleotide deletion, the gene expression of the contribution rate of more than 10% have two sites. On 12 SNPs do haplotype analysis, is divided into 11 haplotypes, and gene expression of the average value of the highest hapbtype type3, type6 is the number of individuals in this haplotype most, but the expression amount at the average level;III. Grain weight and promoter sequences gene association analysis showed, a total of 5 SNPs were mapped to, while they are single base mutation,4 of them have the same grain weight per plant and the contribution rate.5 SNPs are further divided into three haplotypes, typel per plant grain weight average is the most high, type2, contains the number of individuals in the most, but grain weight average at the average level.