Arbuscular mycorrhizal fungi-mediated resistance to salt spray in Cinnamomum camphora seedlings enhanced by leaf functional traits

Salt spray is a natural disturbance in coastal area of Southern China. Arbuscular mycorrhizal fungi can mediate the detrimental effects of salt spray. Leaf thickness and photosynthetic ability are key parameters. Combined fungi may be beneficial for trees grown in coastal areas. Salt spray is a natural disturbance in coastal region. Arbuscular mycorrhizal fungi (AMF) are recognized as bio-ameliorators of soil salinity in plants. However, the mechanism through which AMF protects Cinnamomum camphora against aerial salinity remains unclear. To address this knowledge gap, plants were subjected to four fungal regimes, namely sterilized fungal inoculum, Glomus tortuosum, Funneliformis mosseae , or a combination of these two fungi, and exposed to three sprayed-salt regimes (0, 7, or 14 mg NaCl cm −2 d −1 ) in a greenhouse. Salt spray significantly decreased photosynthetic capabilities, total dry weight, and salinity tolerance of non-mycorrhizal plants. Mycorrhizal inoculation, particularly a combination of G. tortuosum and F. mosseae , evidently mitigated the detrimental effects induced by salt spray. Meanwhile, mycorrhiza-mediated protection depended on the intensity of sprayed salt and the identity of fungal taxa. Furthermore, the enhanced resistance of mycorrhizal C. camphora seedlings to aerial salinity was mainly owing to increased leaf thickness and photosynthetic capabilities. These findings imply that inoculation with combined fungi could be an optimal strategy for cultivating C. camphora plants in coastal regions. The results gained hold the potential to offer both theoretical and practical guidance for the managers of coastal ecosystems in soil restoration and conservation.