Research on lignification of bamboo shoots during its development by metabolomics technology

Lignification is a typical feature of senescence during bamboo shoots development. To investigate mechanisms of lignification, quantitative analysis of a few metabolites from the lignin biosynthesis pathway was carried out using targeted metabolomics analysis. The content of the targeted metabolites such as cinnamic acid, p-coumaric acid, ferulic acid, coniferaldehyde, and sinapaldehyde was measured using ultra high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Meanwhile, enzymatic activity of PAL (phenylalanine ammonia-lyase), POD (peroxidase), 4-CL (4-coumarate CoA ligase), and lignin content in vegetative and mature stage by increased when compared to young bamboo shoots. The results demonstrated that the content of cinnamic acid, p-coumaric acid, ferulic acid, coniferylaldehyde and sinapaldehyde in young stage was significantly higher than it in the vegetative and mature stages. This implied that the biosynthesis of intermediate metabolites in bamboo shoots in the young stage was more vigorous than that in the vegetative and mature stage. Undoubtedly, the synergistic effect of the increase of PAL, POD, and 4-CL activity, coupled with most intermediate metabolites flux away from lignin, was described as a mechanism for effective inhibition on the lignification of bamboo shoots during development. The lignification of bamboo shoots can be restrained by inactivating PAL activity and POD activity during its development. The fate of these metabolites and enzymes would contribute to proposing new measures for preventing browning and lignification of bamboo shoots that degrade their edible quality.