Gene Expression Profiling Of Wheat Roots At Seeding Stage Under Low Phosphorus-stress

The lack of available phosphorus in the soil is an important factor to restrict agricultural production and crop yield, which severely restricts the increase in wheat production. In order to find the key genes and mechanisms of wheat to adapt the low phosphorus stress for wheat breeding, we take use of the gene-chip and the real-time PCR technology to look for and identify genes differential expression in roots under phosphorus-stress, which was on the basis of early screening experiments of P-efficient wheat varieties. Conclusions are as follows:1. Analysis of the Affymetrix wheat Gene-Chip data showed that there were1298genes induced (fold change more than twice) and591genes repressed in roots under phosphorus-stress for14d(day). The764candidate genes annotated were classified into13functional categories, involving in protein processing, stress-related, pathogenesis-related, metabolism, genetic information, signal transduction, membrane transport, cellular processes, protein storage, transcription, cytoskeleton, energy metabolism and others.26.14%of them belonged to the stress-response category, and23.27%were associated with metabolism and21.05%with energy metabolism. In addition, the differential expression patterns of thirty representative candidate genes were confirmed by real-time quantitative PCR. The results showed that the expression changes of twenty-nine genes candidates were generally consistent with the microarray results.2. Among ten candidate genes selected by real-time PCR, there were3genes which had high similarity genes with known function and others were involved TaIPS1.3_Like, TaPDF1_Like,TaG6PDH1_Like,TaMADS2_Like,TaGST28e45_Like, TaNAS1_Like, TaDUF6_Like. The expression of10genes in roots of ZM9023, XN979and YN202at14d (0h) under phosphorus-stress,6h,24h and48h after phosphorus-recovery were detected by real-time PCR. Ten genes were all expression differentially. Then the expression values of TaMADS2_Like gradually restored to normal level at6h which showed the gene was sensitive to phosphorus and TaIPS1.3_Like was still induced at48h which means this gene is affected indirectly by phosphorus-stress and others expression normally at24h or48h which implies they are all related to phosphorus-stress directly or indirectly.TaGST28e45_Like, TaMADS2_Like,TaPiS3in roots of YN202and TaPDF1_Like in roots of XN979were not affected by phosphorus-stress with the time going after phosphorus-recovery.3. The detective values of10candidate genes by real-time PCR in shoots of ZM9023, XN979, YN202and roots of JM17, XY54, XY6, YZ4110, SX828, ZGC and YF18814d after phosphorus-stress showed TaIPS.13-Like, TaPiSl,TaG6PDH1_Like,TaPiS3expression in common with roots and TaIPS1.3_Like, TaPiS1,TaPiS2, TaG6PDH1_Like, TaGST28e45_Like and TaDUF6_Like expression regularly in all genotypes, which means the regulatory mechanism acts in line.Ten genes related to phosphorus-stress were obtained by use of gene-chip and the expression exposed to phosphorus-stress was analyzed with qRT-PCR. Analysis of genes sequence showed preliminarily the function mechanism that how roots adapt the phosphorus-stress, which lays the foundation for gene cloning and transgenic.