Deciphering the mechanism of selenium-induced resistance to TR4 in bananas via proteomic profiling

BACKGROUND: Selenium (Se), an essential trace element for both animals and plants, plays a crucial role in suppressing TR4 (Fusarium oxysporum f. sp. cubense tropical race 4) infection in bananas. Proteins are central to plant disease resistance and defense responses; however, their functions in Se-enhanced disease resistance in bananas remain unclear. Therefore, this study aimed to explore the regulatory effects of Se on banana resistance to TR4 from a proteomic perspective. RESULTS: In this study, we detected the changes in Se content and quantitative traits of banana tissue-cultured seedlings across different generations treated with Se in vitro. Additionally, we investigated the alterations in TR4 infection progression and the responses of antioxidant enzyme system at different time points after pathogen inoculation in the 7th-generation treated seedlings, as well as the changes in protein expression profiles of banana tissue-cultured seedlings at key time points. From the host perspective, this study further clarifies that Se elicits plant innate immunity and enhances banana defense response against TR4 invasion. The protein expression profiles identified that banana glutathione S-transferase, cysteine-related proteins, peroxidase, ABC transporter, and transcription factors (bZIP and MYBS1) are involved in host resistance to TR4 under Se treatment. Furthermore, the function of mitochondrial NADH dehydrogenase in the oxidative phosphorylation pathway (ko00190) during Se-induced disease resistance responses in bananas was further characterized. This suggests that one of the mechanisms by which Se enhances plant disease resistance is maintaining the structural integrity and functional stability of mitochondria. CONCLUSION: This study highlights the significant impact of Se in promoting the expression of disease resistance-related proteins in bananas, and identifies the critical function of banana mitochondrial proteins in resistance to TR4. Therefore, the present study provides valuable insight and practical basis for the application of Se fertilizers as an alternative to fungicides, thereby facilitating the cultivation of disease-resistant crops in agricultural production.