Evaluation of the storage longevity, postharvest quality, and sugar metabolism-related gene expression in two lines (N1 and N3) of Chinese cabbage during long-term storage

The quality and taste of 'Beijing New 3 ' (N3) and Beijing New 1 ' (N1) Chinese cabbage was assessed using physiological indicators monitored during storage and by transcriptome profiling conducted at 0, 25, and 100 d of storage. Results indicated that N3 had better storage longevity and postharvest quality, relative to N1. Electrolyte leakage values in N3 increased at a slower rate than they did in N1 cabbage during the latter stages of storage (125 days), while ethylene levels and respiratory rates were also lower in N3 cabbage than in N1 cabbage during the entire period of storage. The N3 variety had a higher sugar content (mainly glucose and fructose) during storage than the N1 variety. The expression level of genes involved in sugar metabolism, such as hexokinase (HK), sucrose synthase (SUS), phosphofructokinase (PFK), fructose bisphosphate aldolase (FBA), PCKA (Phosphoenolpyruvate carboxykinase), ALDO (aldose), GAPDH (glyceraldehyde phosphate dehydrogenase), and ENO (Enolase) were higher in N3 than in N1, while the expression level of GPI (Glycosylphosphatidylinositol) and PGM (Phosphoglucomutase) was lower. These results provide valuable information on the quality and taste of Chinese cabbage, especially in relation to sugar metabolism, and indicated that N3 had better postharvest storage properties than N1.