The efficacy of melatonin on postharvest quality of Chinese flowering cabbage was investigated in this study. Treatment of Chinese cabbage with melatonin significantly delayed leaf yellowing and maintained higher contents of nutrients such as soluble sugars, protein, vitamin C, total flavonoids and phenols during a 7-day storage. Also, melatonin enhanced the activities and expression level of glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6-PGDH). Melatonin treatment decreased tissue weight loss, respiration rate, activities of phosphohexose isomerase (PHI), succinate dehydrogenase (SDH), cytochrome C oxidase (CCO), and ascorbic acid oxidase (AAO) and the expression of their corresponding genes. Additionally, melatonin-treated leaves maintained high energy status, as evidenced by higher total ATPase and nicotinamide adenine dinucleotide kinase (NADK) activities, higher energy charge level, adenosine triphosphate (ATP) and adenosine diphosphate (ADP) contents, lower level of adenosine monophosphate (AMP) and transcript abundance of respiratory enzymes. These findings collectively suggest that melatonin maintains leaf quality of postharvest Chinese flowering cabbage might be, at least in part, due to the reduced ratio of Embden-Meyerhof-Parnas pathway (EMP), tricarboxylic acid (TCA) cycle, and cytochrome pathway (CCP), a relatively higher level of pentose phosphate pathway (PPP) and energy status.

本研究研究了褪黑激素对大白菜采后品质的影响。褪黑素处理大白菜可显着延缓叶片变黄，并在7天的存储期间保持较高的营养素含量，例如可溶性糖，蛋白质，维生素C，总类黄酮和酚。褪黑素还增强了6-磷酸葡萄糖脱氢酶（G6PDH）和6-磷酸葡萄糖酸酯脱氢酶（6-PGDH）的活性和表达水平。褪黑素治疗降低了组织的重量减轻，呼吸频率降低，磷酸己糖异构酶（PHI），琥珀酸脱氢酶（SDH），细胞色素C氧化酶（CCO）和抗坏血酸氧化酶（AAO）的活性及其相应基因的表达。此外，褪黑素处理过的叶子保持高能量状态，如更高的总ATP酶和烟酰胺腺嘌呤二核苷酸激酶（NADK）活性，较高的能量电荷水平，三磷酸腺苷（ATP）和二磷酸腺苷（ADP）含量，较低的单磷酸腺苷（AMP）水平和呼吸酶转录本丰富度所证明的那样。这些发现共同表明，褪黑素维持大白菜开花后的叶子质量至少可能部分是由于Embden-Meyerhof-Parnas途径（EMP），三羧酸（TCA）循环和细胞色素途径（CCP）的比例降低。 ），磷酸戊糖途径（PPP）和能量状态的水平相对较高。较低的单磷酸腺苷（AMP）水平和呼吸酶的转录本丰度。这些发现共同表明，褪黑素维持大白菜开花后的叶子质量至少可能部分是由于Embden-Meyerhof-Parnas途径（EMP），三羧酸（TCA）循环和细胞色素途径（CCP）的比例降低。 ），磷酸戊糖途径（PPP）和能量状态的水平相对较高。较低的单磷酸腺苷（AMP）水平和呼吸酶的转录本丰度。这些发现共同表明，褪黑素维持大白菜开花后的叶子质量至少可能部分是由于Embden-Meyerhof-Parnas途径（EMP），三羧酸（TCA）循环和细胞色素途径（CCP）的比例降低。 ），磷酸戊糖途径（PPP）和能量状态的水平相对较高。