Resurrection Plants: Novel Genetic Resources and Alternative Dehydration Stress Tolerance Crops

The long-term goals of this integrated research-extension project are to identify and isolate novel genes and unique gene regulatory networks that are responsible for water-deficit and desiccation tolerance in plants, to assess their functional roles in stress tolerance, and to create a novel outreach/extension program that addresses the development of alternative, drought tolerant forage crops through genetic engineering and breeding strategies. We hypothesize that resurrection plants, which are capable of recovering from extreme cellular dehydration within vegetative tissues, have evolved or retained novel genes and regulatory mechanisms not present in sensitive species that can be exploited for engineering improved stress tolerance in crop plants.

The specific objectives and approaches are 1) to initiate rapid, gene discovery efforts for two vascular desiccation tolerant, resurrection species, the ancient Lycophyte S. lepidophylla (club moss) and the monocotyledonous angiosperm Sporobolus stapfianus (African Inselberg grass) through the establishment of expressed sequence tag (EST) databases; 2) to provide a comprehensive description of the gene expression profiles and map the gene networks responsible for desiccation tolerance using oligonucleotide microarray-based expression profiling in closely related species pairs that have retained or lost desiccation tolerance (e.g., S. lepidophylla (tolerant) and S. moellendorffii (sensitive); Sporobolusstapfianus (tolerant) and Sporobolus pyrimidalis (sensitive)); 3) to establish transgenic Arabidopsis lines overexpressing a selection of dehydration candidate genes as an initial step in the functional testing of strategies for improved drought tolerance in target crop species; 4) to establish a integrated research and extension project and Sporobolus breeding program to explore the potential use of this desiccation tolerant grass as a forage and as a founder species for rangeland restoration efforts. The knowledge gained from this integrated research/extension project will have not only broad scientific interest, but also will provide an excellent means to foster outreach efforts with key stakeholders groups in Nevada into the development of alternative crops that require less water.

This research is a collaborative effort among investigators at the University of Nevada, Reno (Biochemistry & Molecular Biology and Animal Biotechnology) and the University of Missouri, Columbia/USDA-ARS.

Fig. 1.The morphology of the “resurrection plant” S. lepidophylla. (A) Greenhouse grown, dehydrated plant that had not been watered for 6 months. (B) Appearance of the same plant 6 hours after rehydration.