Explanation

According to mass-flow hypothesis, there is a mass flow of mineral ions into the root along with transpiration current. Actually, transpiration creates a suction pressure or transpiration pull, conveyed from leaf xylem to root hair, which causes absorption of water from the soil passively. A large amount of ions are also absorbed along with the absorption of water. When the rate of transpiration is high, absorption of water increases due to increased suction pressure and along with water, absorption of ions also increases.