In desert plants, rate of water loss gets reduced due to the presence of:

Cutin is protective, hydrophobic, waxy covering produced by epidermal cells of leaves, young shoots and other aerial parts. It minimises the water lost through transpiration (with the help of stomata) and also reduces pathogen entry.
Lignin hardens the cell wall and provides flexibility, tensile and compressional strength to the cell wall. Suberin is present in cork cells and make the cells impervious to water.