Studies On The Identification Of House Keeping Genes And Screening For The Phosphate Stress Response Genes Of Wheat In Hydroponic Culture System

A wheat hydroponic culture system was established for detecting the wheat phosphate stress and screening for the response genes of wheat phosphate stress. The candidate house-keeping genes of wheat were identified by measuring the mRNA transcription. The technical system established here would allow the researches of wheat phosphate stress at the nutrition strictly controlling condition. The reached results would profit the discovery of house-keeping genes and phosphate stress response genes of wheat. The technical system and results are important for us to find phosphate high-efficient utilizing genes and screen germplasm resource of wheat. The main results as follows:1,Modified Hoagland medium was employed to establish the wheat hydroponic culture system under green house condition. Phosphate stress responses of different genotype wheat were measured by using this system.(1)Under the hydroponic culture established in this research, the experimental wheat plants grew well and performed the typical architecture responses when exposed in Pi deprivation. Hemi-quantitative RT-PCR revealed that the transcriptional level of known Pi response gene differed dramatically.(2)In general the root length of wheat and root/shoot ratio(R/S) arose when the Pi supply was deprived, however, the change models differed among different wheat genotypes: In tested varieties, Chinese spring and Zhou-mai 18 respond to phosphate stress more slowly, Tai-kong 6hao,Yu-nong 202,Yan-zhan 4110 made early response of phosphate stress, following to display trend of platform; A valuable point is that Zheng-mai 9023 showed a manifestly recovery after a morphological response to the Pi deficiency, it might indicate that there existed possible mechanism to reimburse the lasting Pi starvation. The investigation on their molecular basis would offer the useful clue for screening phosphate high-efficient gene resources of wheat and analyzing gene net controlling metabolism of wheat.2,According to the published house-keeping genes of Arabidopsis, ten genes of wheat with high sequence similarity to published genes were obtained by searching in NCBI database. We analyzed expression of candidate genes in space time of different genotypes wheat by Hemi-quantitative RT-PCR. The results showed that ubiquitin-conjugating enzyme(AY736121),translation elongation factor 1 alpha-subunit(M90077),delta-type tonoplast intrinsic protein (U86763) expressed steadily in different organs of Yanzhan 4110 and Zhengmai 9023 in different periods. Three genes have the potential applicability.3,Using comparative genomics method, according to the published phosphate response genes of Arabidopsis and Rice, ten genes of wheat with high sequence similarity to published genes were obtained by searching in NCBI database. We analyzed expression of candidate genes by Hemi-quantitative RT-PCR. The results showed that the four genes of candidate had increased transcription in response to phosphate stress, they were suggested to be important to gene net regulated by phosphate. Further more, transcription of CJ916459 and CJ895163 increased more in root than in shoot,while DQ512334 and BE418377 were opposite, and BE418377 had a low transcription generally. The results gave us references to farther analyze gene expressing net controlling metabolism of phosphate and clone phosphate high-efficient utilizing genes.