Unravelling the molecular network of desiccation tolerance in resurrection plants started with the model plant Craterostigma plantagineum.

Abstract

Main conclusion: Molecular studies of desiccation-tolerant resurrection plants identified major components for surviving severe water depletion of vegetative tissues. The research also highlights potential applications for crop protection during drought. The ability of vegetative plant tissues to withstand desiccation is a property of a small group of resurrection plants specific to specialized ecological niches. In the 1980s, studies on these plants were limited to the physiological and morphological levels. However, in 1990, a study by Bartels et al. using the South African resurrection plant Craterostigma plantagineum was the first to address desiccation tolerance at the molecular level. A differential screening approach with C. plantagineum leaves and callus pretreated with ABA led to the identification of transcripts that were upregulated by desiccation. Many of the identified genes encoded late embryogenesis-abundant (LEA) proteins, which are abundant proteins that accumulate during normal seed development. Therefore, the study confirmed that the acquisition of desiccation tolerance in vegetative tissues of resurrection plants partially involves the seed maturation programme involving ABA. Subsequent research with C. plantagineum contributed to elucidating the gene regulatory networks and metabolic changes that contribute to desiccation tolerance and provided the basis for studies with other resurrection species. More recently, the genomes of C. plantagineum and several other resurrection plants have been sequenced, which has allowed comparative genomics approaches to identify conserved mechanisms and signatures associated with vegetative desiccation tolerance. A primary goal remains to transfer existing knowledge from resurrection plants to genetically engineer drought tolerance in crop plants, which will improve survival during periods of drought and will maintain future food security despite increasing impacts of climate change.