Integrative transcriptomic and metabolomic analysis reveals resistance mechanisms of Dendrocalamus brandisii shoots against Cyrtotrachelus buqueti herbivory

Dendrocalamus brandisii Kurz. is a high-quality bamboo species suitable for timber and bamboo shoot production. However, during its growth, this species is susceptible to infestation by Cyrtotrachelus buqueti Guer, which leads to a decline in bamboo yield and quality, resulting in serious economic and ecological consequences. To investigate the resistance mechanisms of D. brandisii bamboo shoots against C. buqueti , this study used fresh, uninfested D. brandisii bamboo shoots (designated as 0 h) as a control. Enzyme activities and physiological indicators in the bamboo shoots were measured at multiple time points following feeding, and transcriptomic and metabolomic methods were employed to analyze gene expression and metabolic differences in D. brandisii bamboo shoots during these stages. Physiological and biochemical assays showed that the activities of lipoxygenase, phenylalanine ammonia-lyase, polyphenol oxidase, peroxidase, and superoxide dismutase all exhibited an upward trend; lignin and cellulose increased, while total phenols, protein, and soluble sugars decreased. Metabolomic and transcriptomic analyses indicated that the major differentially expressed metabolites in D. brandisii bamboo shoots were amines and phenolic acids, while HPD , HPA , PAL , and JMT were likely key differentially expressed genes. Integrated analysis revealed that these differentially expressed genes and metabolites were enriched in phenylalanine metabolism, tyrosine metabolism, isoquinoline alkaloid biosynthesis, and jasmonic acid (JA)-related pathways (such as α-linolenic acid metabolism and plant hormone signal transduction). These results suggest that D. brandisii bamboo shoots may resist insect damage through the phenylalanine and JA pathways; this study elucidates the mechanism by which D. brandisii resists insect damage following feeding by C. buqueti , laying a preliminary foundation for future efforts to improve the quality of D. brandisii bamboo shoots and control pests and diseases.