Expression of a SK2-type dehydrin gene from Populus euphratica in a Populus tremula × Populus alba hybrid increased drought tolerance

Abstract

A dehydrin gene, isolated from cDNA library established from the root of Populus euphratica, was determined from sequence analysis to be an SK2-type dehydrin (Pedhn). To investigate the function of Pedhn, it was expressed via the CaMV 35S promoter in transgenic Populus tremula × Populus alba. The Pedhn transgenic lines demonstrated higher water retention capacities in excised leaves of transgenic lines than that of wild type, and the rate of water loss in the leaves of transgenic lines were slower than that of wild type controls under drought stress. Higher water retention capacity and reduced water loss suggest that the transgenic lines would exhibit enhanced drought tolerance. Consistently, the seedlings of transgenic lines did have significantly enhanced drought tolerance when compared with that of the wild type controls under drought challenge, which indicated that expression of Pedhn could be used to genetically modify poplar to improve drought tolerance.

Key words: Dehydrin, transgenic poplar, pedhn, drought tolerance.