Comprehensive Transcriptome and Physiological Analysis Reveal the Effects of Cyrtotrachelus buqueti Guer on Carbohydrates in Dendrocalamus brandisii Kurz.

The bamboo shoots of Dendrocalamus brandisii Kurz. are a type of nutritious and delicious vegetable. However, their quality is vulnerable to mechanical damage and pest infestation, which reduces their economic benefits. In order to study the effects of mechanical damage and pest infestation on the quality of bamboo shoots, the changes in the contents of carbohydrates, water, amino acids, proteins, total phenols, and lignin in bamboo shoots after mechanical damage and insect feeding were assessed through transcriptomics combined with physiology; additionally, these changes were analyzed and compared to the gene expression and physiological changes in bamboo shoots under different treatments. The results show that both mechanical damage and insect feeding can lead to an increase in the contents of starch, cellulose, hemicellulose, lignin, amino acids, and proteins, as well as a decrease in the contents of water, soluble sugars, and total phenols. Moreover, the changes in the insect feeding group were particularly significant. In addition, through transcriptomic analysis of bamboo shoots after mechanical damage plus insect feeding at 3, 6, 12, and 24 h, 1698, 29,786, 18,853, and 10,544 differentially expressed genes were screened out, respectively. Combined with physiological indexes, the GO and KEGG enrichment analyses revealed that a large number of differentially expressed genes were found in the sucrose and starch metabolism pathways, which might be related to the carbohydrate accumulation in bamboo shoots, suggesting that the impact of insect feeding on the quality of bamboo shoots is greater than that of mechanical damage. This study provides a reference for carbohydrate accumulation in D. brandisii Kurz. bamboo shoots and the impact of Cyrtotrachelus buqueti Guer feeding on their quality, as well as offering some ideas for improving the quality of bamboo shoots.