Resurrection plants

Plant growth and hence agricultural expansion especially in arid and semi-arid regions is limited by water availability and several other environmental factors. Most crop plants are very sensitive to drought even mild one. However, several higher plants were found to be tolerant to drought and even desiccation to about 4-8% relative water content of fresh weight. This phenomenon is in the context of drying pollen grains and seeds. These plants are liThe resurrection plants. They do not belong to any specific taxa and usually grow in arid and semi-arid lands. These plants survive desiccation and resume growth as soon as water is available within 12 to 24 hours. Their air-dry leaves survive for long time (2-5 years) and unlimited dehydration and hydration cycles. These plants seem of no economical value so far, but studying their mechanism(s) of tolerance might leads to establishing drought-tolerant crop plants , i.e. transgenic crop plants through genetic engineering. The possible mechanism(s) are discussed according to available information in the literature. It seems that the mechanism of drought tolerance is complicated and require coordination of expressing several genes.