Preliminary Characterization of the DREB Genes in Transgenic Wheat

Abstract

Drought is one of the major causes of yield loss in crops, significantly affecting world food production. Considerable efforts have been devoted during the past decade to improving the level of drought tolerance in wheat and extensive research has been conducted in the areas of breeding, physiology and agronomy. To date, reasonable progress has been achieved through conventional breeding (Trethowan, 2001). However this approach is slow, time consuming, and due to the genetic complexity of the wheat plant’s response to water-limited conditions, potential for further progress is uncertain. Recently, several candidate genes have been identified that could improve a plant’s response under water-limited conditions (Soderman et al., 2002). These genes can be divided in three classes; firstly, genes where very strong evidence already has been published demonstrating their significant role under abiotic stresses conditions; secondly, genes that have been identified as of interest but still require further evaluation (Liu et al., 1998); and thirdly, those genes that have not been evaluated in a plant, and therefore still need to be confirmed under experimental conditions. Of particular interest are the DREB genes, identified in Arabidopsis and rice, which have been reported to increase the level of tolerance to abiotic stresses in Arabidopsis.