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 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.

Arbuscular mycorrhizal fungi protect a subtropical tree species exposed to simulated acid rain by accelerating photosynthetic ability,antioxidant enzymes and osmolyte accumulation

Acid rain(AR),which occurs frequently in southern China,negatively affects the growth of subtropical tree species.Arbuscular mycorrhizal fungi(AMF)mitigate the detrimental effects induced by AR.However,the mechanisms by which AMF protect Zelkova serrata,an economically important tree species in southern China,from AR stress remain unclear.We conducted a greenhouse experiment in which Z.serrata plants were inoculated with AMF species Rhizophagus intraradices and Diversispora versiformis,either alone or as a mixed culture,or with a sterilized inoculum(negative control).The plants were subjected to three levels of simulated sulfuric AR and nitric AR(pH 2.5,4.0 and 5.6)to examine any interactive effects on growth,photosynthetic capabilities,antioxidant enzymes,osmotic adjustment and soil enzymes.AR significantly decreased dry weight,chlorophyll content,net photosynthetic rate and soluble protein(SP)of non-mycorrhizal plants.Mycorrhizal inoculation,especially a combination of R.intraradices and D.versiformis,notably improved dry weight,photosynthetic capabilities,catalase,peroxidase,superoxide dismutase,SP and root acid phosphatase activity of Z.serrata under harsh AR stress.Moreover,the benefits from AMF symbionts depended on the identity of AM fungal species and the gradient of AR stress.Our results indicate that AM fungi protect z.serrata against AR stress by synchronously activating photosynthetic ability,antioxidant enzymes and osmolyte accumulation.These findings suggest that a combination of R.intraradices and D.versiformis may be a preferable choice for culturing Z.serratain southern China.