二氢卟吩铁缓解胶孢炭疽菌胁迫杉木生长的作用效应OA

To investigate the alleviation effect of a novel plant growth regulator,0.02％iron chlorin e6(ICE6)water-soluble powder,on Cunninghamia lanceolata growth under stress caused by Colletotrichum gloeo-sporioides,this study used C.gloeosporioides as the test pathogen and 2-year-old C.lanceolata seedlings from Yangkou Forest Farm,Fujian Province as experimental materials.Seedlings were treated with iron chlorin e6 solutions at different concentrations(0.01,0.02,0.04,and 0.08 μg/mL),and each treatment group was sprayed with a C.gloeosporioides spore suspension(5 × 106 spores/mL).The impacts of different concentrations of 0.02％ICE6 on induced resistance in C.lanceolata,malondialdehyde(MDA)content in leaves,and the activity of anti-oxidant enzymes were measured.Results showed that:plate antibacterial assays indicated no significant differ-ences in the inhibition rates of C.gloeosporioides among different concentrations of ICE6.Under C.gloeo-sporioides stress,spraying 0.08 μg/mL iron chlorin e6 solution significantly enhanced C.lanceolata resistance to C.gloeosporioides.Biofilm damage assessments revealed that after spraying iron chlorin e6 solutions at various concentrations and subsequent inoculation with C.gloeosporioides,MDA content in plant leaves was signific-antly lower than in the control group,with the 0.08 μg/mL treatment group exhibiting the lowest degree of mem-brane lipid peroxidation damage.Antioxidant enzyme activity assays demonstrated that spraying 0.08 μg/mL iron chlorin e6 significantly increased SOD,POD,and CAT activities in C.lanceolata leaves.Scanning electron mi-croscopy(SEM)observation of leaf ultrastructure showed that treatment group leaves were smoother than control leaves,with no hyphal invasion observed in mesophyll tissues.In summary,application of 0.02％ICE6 water-sol-uble powder at various concentrations alleviated the occurrence of C.lanceolata anthracnose.Prolonged treat-ment activated the host's systemic defense responses and enhanced seedling resistance to C.gloeosporioides.Among these,plants sprayed with 0.08 μg/mL iron chlorin e6 solution exhibited the mildest disease severity,the least damage to the cell membrane system,and the strongest activity of the antioxidant enzyme system after pathogen inoculation.