The isolation of genes from the resurrection grass Sporobolus stapfianus which are induced during severe drought stress

Abstract

A modification of the 'cold plaque' screening technique (Hodge et al., Plant Journal 1992, 2, 257-260) was used to screen a cDNA library constructed from drought-stressed leaf tissue of the desiccation tolerant ('resurrection') grass Sporobolus stapfianus. This technique allowed a large number of clones representing genes expressed at low abundance to be isolated. An examination of expression profiles revealed that several of these genes are induced in desiccation-tolerant tissue experiencing severe drought stress. Further characterization indicated that the gene products encoded include an eIF1 protein translation initiation factor and a glycine- and proline-rich protein which have not previously been associated with drought stress. In addition, genes encoding a serine/threonine phosphatase type 2C, a tonoplast-intrinsic protein (TIP) and an early light-inducible protein (ELIP) were isolated. A number of these genes are expressed differentially in desiccation-tolerant and desiccation-sensitive tissues, suggesting that they may be associated with the desiccation tolerance response of S. stapfianus. The results indicate that there may be unique gene regulation processes occurring during induction of desiccation tolerance in resurrection plants which allow different drought-responsive genes to be selectively expressed at successive levels of water loss.