Selection Of Control Gene In Quantitative PCR And Analysis Of Differential Expression Of P5CS Gene In Agropyron Mongolicum Keng Under Drought Stress

Agropyron mongolicum Keng with a high feeding value and ecological value is a perennial herb of Agropyron species in Poaceae, and distributes in Inner Mongolia, the northwest of Shanxi, the northern of Shaanxi, Gansu, Ningxia, and Xinjiang of China and other regions include Mongolia and some countries in Central Asia. Agropyron mongolicum as an important herbage on arid and desert steppe usually grows in the area with an annual rainfall from200to300mm.In this study, Agropyron mongolicum was selected as the research material. Under water stress, the stabilities of nine control genes(actin2,18S rRNA, APRT, EF-1α, RNApollⅡ, TUBa, TUBβ, GAPDH and TLF) expression in plant of Agropyron mongolicum were determined by using real-time PCR technology. The optimum control gene was screened for analyzing P5CS gene expression in plant of Agropyron mongolicum under drought stress and rewatering. The results are as follows:1. Under drought stress, the expression of18S rRNA control gene was the most stable, follow by EF-1α and TLF, and expression of actin2was the most unstable in plant of Agropyron mongolicum.2.18S rRNA and TLF was optimum control genes considered as the best selection of control gene for analysis of gene expression in plant of Agropyron mongolicum under drought stress in future.3. Proline levels in the leaves of Agropyron mongolicum apparently increased on the third day after drought treatment, up to the highest level on the15th day. After rewatering, proline levels apparently decreased and recovered on the6th day after rewatering.4. The expression level of P5CS gene was induced by drought stress. On the third day after drought treatment, the expression of P5CS gene apparently increased, up to the highest level on the12th day and then decreased but still higher than controls. The expression level of P5CS gene decreased on the third day after rewatering and nearly recovered on the6th day.5. Under drought stress and rewatering, there was a positive correlation between the content of free proline and expression level of P5CS gene in Agropyron mongolicum, and the the correlation coefficient reached R2=0.7703,(P<0.05).