Isolation and characterization of an Aux/IAA gene (LaIAA2) from Larix
The phytohormone auxin controls many aspects of plant development. Auxin/indole-3-acetic acid (Aux/IAA) transcriptional factors are key regulators of auxin responses in plants. To investigate the effects of auxin on gene expression during the rooting process of Larix cuttings, a subtractive cDNA library was constructed and 272 UniEST were obtained by using suppression subtractive hybridization (SSH). Based on a fragment of 272 UniEST, the full-length cDNA of LaIAA2, an Aux /IAA gene from Larix was isolated. Then, the response expression of LaIAA2 to auxin was determined by treating with different sources and concentration of auxin and cycloheximide and the expression patterns of LaIAA2 were examined in different tissues. The results show that LaIAA2 appears to be the first response gene of auxin and LaIAA2 gene was involved in the root development and auxin signaling. The express pattern of LaIAA2 gene indicated that it might play a central role in root development, specially regulated lateral and adventitious root production.
Key words: Aux/IAA gene family, auxin, LaIAA2, Larix