Endophytic Beauveria bassiana promotes sunflower growth and confers resistance against sclerotinia disease

Sunflower, a significant oleaginous crop with horticultural applications, faces challenges in yield and quality due to Sclerotinia sclerotiorum infection. As an endophyte, Beauveria bassiana demonstrated promise as a dual-purpose biocontrol agent, suppressing plant phytopathogens and inducing plant resistance against pests. While its role as an endophyte has been explored in leaf diseases, its efficacy against soil-borne diseases, especially sclerotinia disease, remains underexplored. In the present study, we evaluated the colonization ability of B. bassiana in sunflower plants through seed soaking and root irrigation methods. Additionally, we investigated its potential benefits in promoting plant growth and mitigating the negative effects of S. sclerotiorum infection. Our results showed that B. bassiana presented as an endophyte in sunflowers with both seed soaking and root irrigation treatments, leds to enhanced plant growth. Moreover, B. bassiana colonization significantly suppressed S. sclerotiorum infection in sunflower plants, even under conditions of artificial inoculation and infested soil. These findings indicate the promising ecological role of B. bassiana as a safe and effective strategy for biological control of sclerotinia disease in agroecosystems.