Expression Profiles of P5CS and DREB2 Genes under Salt Stress in Aegilops cylindrica

Aegilops cylindrica Host. is a salt-tolerant wild relative of wheat. The expression of AecDREB2 and AecP5CS genes involved in salinity tolerance was investigated. Salt stress caused significant upregulation of AecDREB2 expression while it did not affect the transcripts of AecP5CS. Despite no significant difference in the AecDREB2 expression in the root and shoot tissues, the AecP5CS transcription profiles of the shoots was much higher than the roots supporting our data of proline accumulation in these tissues. In addition, the homology between AecP5CS and TaP5CS as well as between AecDREB2 and AetDREB2 may suggest the location of our studied genes in the D genome of Ae. cylindrica and a clear orthologous relationship. It is concluded that proline did not play an explicit role in the adaptation response of Ae. cylindrica to a high level of salt stress, while DREB2 plays a pivotal role in the regulatory network of salt tolerance in this species.