Explanation:

Leaf modifications of desert plant take place to minimize the  water loss for adaptations and survival of desert plant.

Wax coatings on leaves prevent water loss through evaporation, which in the hot desert can cause loss of water from both the surface and the inside of leaves.

Many cacti have spines in place of leaves, which conduct photosynthesis and catch dew when the climate is right. These small structures also reflect light, Tiny leaves  further reducing water loss. During heavy rains, cacti will grow temporary root systems and absorb water.