Cloning And Physical Chromosome Mapping Of The Nitrate And Phosphate Related Genes In Common Wheat

Wheat is one of the most important staple food crops of the world, occupying 17% of crop acreage worldwide, and providing 20% of total food calories and protein in human nutrition. Due to spread high-yield cultivars and improve culture techniques, wheat production had a steady significant increase during the last few decades. In order to meet growing human needs, next forty years, grain yield must increase at an annual rate of 2%.Huge amount of fertilizers lead to economic cost and environmental pollution. Both improvement of grain production and reduction of fertilizer input are necessary. It is critical to understand functional genomics on fertilizer-use efficiency in common wheat.In this study, we focused on genome-wide gene profiling in response to nitrate or phosphate deficiency based on microarray analysis, and constructed high-density physical chromosome map through deletion mapping and in silico mapping. The results are as follows:1.Based on genome-wide gene profiling, we screened thousands of probe sets. In response to nitrate or phosphate deficiency, the probe sets changed greater than 3 fold or 4 fold compared to control plant were selected, respectively.2.We isolated 48 genes related to nitrate and phosphate metabolism and regulation (full or partial length), including acid phosphatase, inorganic phosphatase, malic enzyme, SPX domain protein, RNase S-like protein precursor, WRKY transcription factor and so on. Ninety-two alleles of phosphate and nitrate related genes (PNRG) were detected with an average of 1.92 loci, while the alleles of each PRNG ranged from 1 to 5.3.Fifty-six alleles of 27 genes were localized into chromosome by nulli-tetrasomic lines, while forty-eight were divided into chromosome bin based on ditelcentics and deletion lines.4.Through bioinformatics analysis, we integrated and utilized Unigene database, mapped-EST database as well as Affymetrix consensus database in common wheat. We isolated 316 nitrate and phosphate related unigenes and mapped to chromosome bin in silico.5.Further, we mapped 364 nitrate and phosphate related genes by deletion mapping and in silico mapping into a chromosome bin, in which more than one thousand loci distributed to different genomes, homologous groups, chromosomes. In total,523 nitrate related loci and 797 phosphate related loci are identified, respectively.6.A high-density physical deletion map of PNRG was first constructed in common wheat. Then, we preliminarily demarcated gene-rich region (GRR) and gene-poor region (GPR) of PNRG. Most GRRs of PNRG have been localized to the distal ends of chromosomes, while GPRs in the proximal ends. According to the results, we suspected that GRRs of PNRG were consistent with gene-rich regions in wheat. As the large sizes of nitrate and phosphate related GRRs ranged from 3Mb to 121Mb, through genetic map construction and comparative genomics analysis with rice and Brachypodium distachyon, fine-mapping of PNRG in wheat is required.