Chinese flowering cabbage is an important cultivated leafy vegetable. Experiments were conducted to test the effect of exogenous application of N-phenyl-N-(2-chloro-4-pyridyl) urea (CPPU) as a cytokinin analogue on postharvest attributes of Chinese flowering cabbage during storage at low temperature. The results revealed that CPPU treatment significantly delayed the de-greening of Chinese flowering cabbage. The treatment reduced the H₂O₂ accumulation, O₂^.− production rate and malondialdehyde content, maintained membrane permeability and delayed the decrease in the contents of total unsaturated fatty acids. Meanwhile, the deficiency of energy status referred to the ATP level and energy charge in relation to the expressions of energy-related genes of Chinese flowering cabbage was slowed down after CPPU treatment. Furthermore, the decreases in the contents of chlorophylls, the transcript levels of chlorophyll catabolic genes BrPAO1, BrPPH1, BrSGR1 and BrNYC1 and senescence associated genes BrSAG12 and BrSAG19 were markedly suppressed. These results exhibited that exogenous application of CPPU efficiently retarded the oxidative damage of membrane integrity, helped to maintain the energy status, slowed down the rapid degradation of chlorophylls and, thus, delayed the leaf senescence of Chinese flowering cabbage during storage, which suggested that the application of CPPU might be as a postharvest handling for quality maintenance and shelf life extension of leafy vegetables.

大白菜是一种重要的栽培叶类蔬菜。进行了实验以测试在低温贮藏期间外源施用N-苯基-N-（2-氯-4-吡啶基）尿素（CPPU）作为细胞分裂素类似物对大白菜收获后特性的影响。结果表明，CPPU处理显着延迟了大白菜的去绿。该处理减少了H ₂ O ₂积累O ₂ ^.-生产速率和丙二醛含量，保持膜通透性并延迟总不饱和脂肪酸含量的减少。同时，CPPU处理后，与白菜能量相关基因的表达相关的能量状态不足称为ATP水平和能量电荷。此外，叶绿素含量的减少，叶绿素分解代谢基因BrPAO1，BrPPH1，BrSGR1和BrNYC1的转录水平以及衰老相关基因BrSAG12和BrSAG19的减少。被明显压制。这些结果表明，CPPU的外源施用有效地抑制了膜完整性的氧化损伤，有助于维持能量状态，减缓了叶绿素的快速降解，从而延迟了大白菜在贮藏过程中的叶片衰老。 CPPU的应用可以作为收获后的处理，以保持叶类蔬菜的质量并延长其货架期。