Phosphate Transporter MdPHT1;7 Enhances Phosphorus Accumulation and Improves Low Phosphorus and Drought Tolerance

Phosphorus is an important macronutrient for plant growth and is acquired by plants mainly as phosphate. Phosphate fertilizer is usually used to reduce inorganic phosphate (Pi) deficiency in the soil, improve the low phosphorus and drought tolerance of plants, and promote plant growth. Phosphate transporters (PHTs) play an important role in absorbing phosphorus from the soil. MdPHT1;7 was induced by Pi deficiency and drought in roots in our previous research. In this study, we cloned MdPHT1;7 and showed its heterologous expression can complement a high-affinity Pi transporter gene in the Pi uptake-defective yeast mutant BY4743. MdPHT1;7 is a phosphorus transporter located on the cell membrane. Overexpression of MdPHT1;7 in ‘Orin’ apple and ‘Micro-Tom’ tomato enhanced Pi accumulation, low Pi tolerance and drought tolerance. We hypothesized that MdPHT1;7 can enhance Pi absorption and play an important role in improving plant resistance to low phosphorus and drought stresses.