Trichoderma asperellum 22043: Inoculation Promotes Salt Tolerance of Tomato Seedlings Through Activating the Antioxidant System and Regulating Stress-Resistant Genes

Salt stress poses a major threat to plant growth, and breeding for salt-tolerant varieties is not always successful to ameliorate this threat. In the present experiment, the effect of <i>T. asperellum</i> 22043 inoculation on the growth of salt-stressed tomatoes and the mechanisms by which it improves salt tolerance were investigated. It was observed that tomato plants treated with <i>T. asperellum</i> 22043 spore suspension under salt tress (50 and 100 mM NaCl) consistently exhibited higher seeds germination, seedling survival rate, plant height, and chlorophyll content, but lower malondialdehyde and proline contents than the plants treated without the <i>Trichoderma</i>. <i>T. asperellum</i> 22043 effectively improved the stress resistance of tomato through regulating the transcriptional levels of reactive oxygen species (ROS) scavenging enzyme gene expression to modulate the activity of ROS scavenging enzymes and the expression of the genes related to transporter and aquaporin to maintain the balance of cell Na⁺. In conclusion, <i>T. asperellum</i> 22043 can enhance tomato seedlings' salt tolerance by activating the antioxidant system and regulating the expression of stress-resistant genes.