Resistance of Mycorrhizal Seedlings to Salt Spray Depends on K and P Uptake.

Salt spray is a major environmental issue in coastal areas. is an economically important tree species that grows in the coastal areas of southern China. Arbuscular mycorrhizal fungi (AMF) can alleviate the detrimental effects of abiotic stress on host plants. However, the mechanism by which AMF mitigates the adverse effects of salt spray on remains unclear. A pot experiment was conducted in a greenhouse, where seedlings were exposed to four AMF regimes (inoculation with sterilized fungi, with , , either alone or in combination) and three salt spray regimes (applied with distilled water, 7, and 14 mg NaCl cm) in order to investigate the influence on root functional traits and plant growth. The results showed that higher salt spray significantly decreased the K uptake, K/Na ratio, N/P ratio, total dry weight, and salinity tolerance of non-mycorrhizal plants by 37.9%, 71%, 27.4%, 12.7%, and 221.3%, respectively, when compared with control plants grown under non-salinity conditions. Mycorrhizal inoculation, particularly with a combination of and , greatly improved the P uptake, total dry weight, and salinity tolerance of plants grown under higher salt spray conditions by 51.0%, 36.7%, and 130.9%, respectively, when compared with their counterparts. The results show that AMF can alleviate the detrimental effects of salt spray on seedlings. Moreover, an enhanced uptake of K and P accounted for the resistance of the plants to salt spray. Therefore, pre-inoculation with a combination of and to improve nutrient acquisition is a potential method of protecting plants against salt spray stress in coastal areas.