Molecular cloning and expression analysis of an Aux /IAA gene( RgIAA1) from Rehmannia glutinosa

To clone and analyze a member of the Auxin/indole-3-acetic acid( Aux/IAA) gene family,RgIAA1,from Rehmannia glutinosa. The transcriptional EST database of R. glutinosa was used to clone the new Aux / IAA gene by cDNA probe of AtIAA14. Bioinformatics was applied to analyze the sequence characteristics of RgIAA1 protein and construct phylogenetic trees. Quantitative RTPCR has been applied to detect the transcription level of RgIAA1 in seven tissues as well as in leaves under three stresses. The results showed that,the cDNA sequence of RgIAA1 contains 903 bp was obtained. The open reading frame( ORF) of RgIAA1 was 681 bp encoding 226 amino acids,which has typical structural domains and characteristic sequence of Aux / IAA family proteins. RgIAA1 showed the highest expression level in unfolded leaf,followed by the stem. And the expression of RgIAA1 was quickly decreased with leaf growing up. The transcription level increased under continuous cropping conditions while it reduced both in salinity and waterlogging stresses. RgIAA1,an Aux / IAA gene from R. glutinosa has been obtained for the first time,which can lay the foundation for further studies about its molecular function in development and responses to stress.