Abstract:

Universal stress proteins（USP）involve in multiple abiotic responses including drought stress,heat stress,nitrogen deficiency and salt stress. To explore the expression pattern of USP gene in Festuca arundinacea,a USP was cloned through rapid amplification of cDNA ends from the leaves of F. arundinacea,and designated as FaUSP. The sequence analysis results showed that the full-length cDNA（844 bp）was obtained with a predicated 501 bp open reading frame,which encoded 166 amino acids,and it had the typical USPA domain of USP family. Phylogenetic analysis revealed that FaUSP in the F. arundinacea was most closely related to USP from other Gramineae plants such as Hordeum vulgare,Triticum aestivum and Aegilops tauschii. The qRT-PCR results show that expression of FaUSP gene was up-regulated after induced via drought stress,heat stress,nitrogen deficiency and salt stress. A plant overexpression vector was constructed and transformed into chicory by Agrobacterium infection. The soluble protein,glutathione reductase（GR）,superoxide dismutase（SOD）,peroxidase（POD）,and catalase（CAT）in the FaUSP overexpression strains were significantly higher than that of wild-type under drought stress. These results indicate that overexpression of FaUSP gene enhances the drought resistance of chicory,thus it is speculated that USP gene is associated with drought resistance.

Key words: Festuca arundinacea, FaUSP, cloning, genetic transformation