Abstract Pak choi (Brassica rapa ssp. chinensis) is a popular, yet highly perishable, leafy vegetable that is conventionally stored in the dark or shade. In this study, we analyzed the effects of light quality, light intensity, and irradiation duration on its postharvest senescence at 20 °C. Red light most strongly inhibited its senescence as shown by slower loss of photochemical efficiency (Fv/Fm ratio) and higher contents of chlorophyll, vitamin C, and total soluble proteins, while blue light had a much weaker effect. Red light inhibited the expression of putative chlorophyll degradation and senescence-associated genes, while promoting the expression of putative vitamin C biosynthetic genes. A daily irradiation of red light (35 μM m−2 s−1) for eight hours is optimal for delaying the senescence of its leaves. In contrast, far-red light treatment promoted its leaf senescence, indicating that phytochrome signaling is likely involved in the regulation of the postharvest senescence of pak choi.

中文翻译：

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LED红蓝光照射对白菜采后衰老影响的分子生理学分析

摘要 白菜（Brassica rapa ssp. chinensis）是一种受欢迎但极易腐烂的多叶蔬菜，通常储存在黑暗或阴凉处。在这项研究中，我们分析了光质量、光强度和照射时间对其 20 °C 采后衰老的影响。红光对其衰老的抑制作用最强，表现为光化学效率（Fv/Fm 比值）损失较慢，叶绿素、维生素 C 和总可溶性蛋白质含量较高，而蓝光的作用要弱得多。红光抑制假定的叶绿素降解和衰老相关基因的表达，同时促进假定的维生素 C 生物合成基因的表达。每天照射红光 (35 μM m−2 s−1) 8 小时是延缓叶片衰老的最佳方法。相比之下，