). Developing scab-resistant cultivars offers a sustainable solution for disease management. To elucidate the metabolic basis of resistance, we applied a pathway-based metabolomics that examines metabolites within pathways relevant to plant-pathogen interactions across 15 orchard-grown pecan cultivars with varying resistance levels. Machine learning models including support vector machine, random forest, and linear regression identified biomarkers predictive of resistance, achieving over 97% classification accuracy. Resistant cultivars showed elevated levels of metabolic precursors supporting lignin biosynthesis, energy metabolism, and antioxidant turnover, such as syringin, proline, and galactono-1,4-lactone, indicating a proactive and coordinated defense strategy. In contrast, susceptible trees accumulated defense-related end-products (e.g., salicylate glucoside, ascorbic acid) and nitrogen-rich amino acids, but showed limited availability of precursors, potentially contributing to increased susceptibility. These metabolic traits will support breeding of disease-resilient cultivars and improve disease management strategies in pecan orchards.
Kang et al. (Wed,) studied this question.