PLANT DESICCATION TOLERANCE: A SURVIVAL STRATEGY WITH EXCEPTIONAL PROSPECTS FOR CLIMATE-SMART AGRICULTURE

Drought is one of the main threats to agriculture worldwide because most of our staple crops are not very tolerant to dehydration stress. Some 135 species of angiosperms, however, are extremely tolerant of severe drought. These so-called resurrection plants are desiccation tolerant because they can withstand drying to water contents below 0.1 gram water per gram dry weight and remain viable for extended periods of time, similar to most seeds. Indeed, recent research has shown that mechanisms of desiccation tolerance of different species, be it vegetative tissues or seeds, utilise the same basic ingredients, including anti-oxidants, chaperone proteins, and specific carbohydrates. However, there is species-specific behaviour, related to habitat, e.g. in cell wall properties and the manner in which photo-oxidative damage is prevented upon drying. Crop plants produce desiccation-tolerant seeds and, hence, possess the genomic information required for desiccation tolerance, but this is exclusively expressed in the seeds. Elucidation of the mechanisms of desiccation tolerance may enable the `release' of this characteristic in the leaves, stems, and roots.