Molecular characterisation of a DREB gene from Sophora moorcroftiana, an endemic species of plateau.

Various plant species in the Qinghai-Tibet Plateau exposed to harsh conditions, such as low oxygen, drought, extremely low temperatures and salinity, have evolved both molecular and physiological adaptation strategies to deal with these multiple stresses. Sophora moorcroftiana (Benth.) Baker (Fabaceae) is a highly drought-resistant endemic Sophora shrub species in the Qinghai-Tibet Plateau. In our previous study, a drought-induced DREB transcription factor gene was identified and was designated as SmDREB1. SmDREB1-GFP fusion construct was introduced into Arabidopsis protoplast to characterise the function of SmDREB1 in drought resistance. The results showed that SmDREB1 targets the nucleus of Arabidopsis protoplast. Ectopic expression of SmDREB1 in model plant species Arabidopsis was performed. The transgenic lines showed increasing expressions of drought marker genes including AtDHN, AtLEA, AtPIP2 ;2, AtPIP2;3 and AtRD29, increasing activities of antioxidant enzymes and proline contents and increasing light-use efficiency under drought stress as compared with the wild-type plants; SmDREB1 transgenic lines are more resistant to drought than wild-type plants. Therefore, the SmDREB1 is a drought-resistant transcription factor gene of S. moorcroftiana and could be a candidate in genetic engineering to improve drought resistance of plateau plant species.