Physiological and molecular insights into drought tolerance

Water is a major limiting factor in world agriculture. In general, most crop plants are highly sensitive to even a mild dehydration stress. There are however, a few genera of plants unique to Southern Africa, called "resurrection plants" which can tolerate extreme water loss or desiccation. We have used Xerophyta viscosa, a representative of the monocotyledonous resurrection plants to isolate genes that are associated with osmotic stress tolerance. Several genes that are differentially expressed, and that confer functional sufficiency to osmotically-stressed Escherichia coli are being studied at the molecular and biochemical levels. In this review, we use this as a basis to discuss the physiological and molecular insights into drought tolerance.