Strawberry Fusarium wilt, mainly caused by Fusarium oxysoporum f. sp. Fragariae (Fof), seriously threatens the yield and quality of strawberry. Piriformospora indica is an endophytic fungus that can colonise the roots of a wide range of plants, promoting plant growth and enhancing plant resistance. Against this background, the positive effects of P. indica on the growth of the daughter plants of ‘Benihoppe’ strawberry (Fragaria × ananassa Duch.) under Fof stress were investigated in this study. The study began by examining the inhibitory effect of P. indica on Fof growth through dual culture on agar plates. Subsequently, a symbiotic system between P. indica and strawberry plantlets was established, and the impact of P. indica on Fusarium wilt resistance and related physiological and biochemical indexes of the plantlets were evaluated. The results indicate that fungus colonization with P. indica significantly enhances the growth indices of strawberries, including plant height, petiole length, petiole diameter, and leaf area. Additionally, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the leaves of P. indica were increased, and the content of malondialdehyde (MDA) was decreased compared to those without colonization. Under the stress from Fof, the growth indexes of plant height, stem diameter, leaf area, petiole diameter, and root length of strawberry plants colonization with P. indica were significantly higher than those without colonization and the symptoms of wilting were relatively mild. The activities of SOD, POD, and CAT in roots and leaves of plants colonized with P. indica were significantly increased compared to those without colonization. Furthermore, the content of MDA in roots was decreased. These results suggested that P. indica could increase resistance to Fusarium wilt in strawberry by increasing the activity of antioxidant enzymes and reducing the content of MDA.

Banana is a globally important food crop. As a large herbaceous plant with a shallow root system, its yield is highly susceptible to drought stress. ANP family genes play crucial roles in plant drought resistance. However, the ANP gene family has not been systematically studied in bananas, and how Piriformospora indica (P. indica) induces its expression remains unclear. A comprehensive identification of the ANP family is thus a necessary foundation for functional studies. In this study, we systematically identified 13 ANP family members in banana for the first time through genome-wide analysis. Using bioinformatics, RT-qPCR and subcellular localization techniques, we characterized their structural features, phylogenetic relationships, and the expression patterns of MaNPK1 under drought stress and P. indica colonization. The results revealed that banana ANP family members are highly evolutionarily conserved. MaNPK1-1 was specifically induced and upregulated by P. indica under drought conditions and subcellular localization showed that it played a role in the nucleus. This research provides theoretical insights into the function of the banana ANP family and its regulatory role in the P. indica mediated drought stress response, offering potential applications for breeding stress resistant banana varieties.