Xi Xiaoyuan, Song Jia, Feng Mengqing, Li Jing, Li Liqin
TCM (Traditional Chinese Medicine) Key Laboratory Cultivation Base of Zhejiang Province for the Development and Clinical Transformation of Immunomodulatory Drugs, Huzhou Central Hospital, Fifth School of Clinical Medicine of Zhejiang Chinese Medical University, 1558 Sanhuan North Road, Huzhou, Zhejiang, 313000, China.
Affiliated Huzhou Hospital, Zhejiang University School of Medicine, Huzhou, Zhejiang, China.
Plant Foods Hum Nutr. 2025 Jun 12;80(3):136. doi: 10.1007/s11130-025-01376-x.
Saffron, a plant flowering in fall and prized for its medicinal red stigmas, has a unique life cycle. After dormancy, the flower formation process starts from late summer to fall. Post-harvest, it enters the vegetative growth stage from winter to spring. The reason behind its growth pattern remains unknown. In our study, we found that overexpressing carotenoid cleavage dioxygenase 2 (CsCCD2L, a long transcript of CsCCD2) in Arabidopsis thaliana affected the content of zeaxanthin and light tolerance. In saffron, CsCCD2L varies throughout its life cycle, impacting zeaxanthin content. Saffron flowers indoors with its leaves still enclosed in sheathing cataphylls. The expression of CsCCD2L in saffron leaves reached its peak on the day of anthesis, but significantly decreased in the vegetative stage when leaves extend from the sheathing cataphylls for photosynthesis. Intense light during this stage leads to leaf yellowing, a reduction in CsCCD2L expression, and an increase in zeaxanthin content. These results indicate that CsCCD2L regulates the content of zeaxanthin and light tolerance. Moreover, CsCCD2L exhibited the highest expression in the orange stigmas. Subjecting flower buds at the orange stigma stage to intense light significantly reduced the crocin content in mature stigmas. Collectively, these results not only shed light on the unique growth pattern of saffron but also offer promising avenues for enhancing saffron quality through the precise manipulation of light intensity and the expression of CsCCD2L.
藏红花是一种在秋季开花且其药用红色柱头备受珍视的植物，它具有独特的生命周期。休眠过后，从夏末到秋季开始花芽形成过程。收获后，它从冬季到春季进入营养生长阶段。其生长模式背后的原因尚不清楚。在我们的研究中，我们发现拟南芥中过表达类胡萝卜素裂解双加氧酶2（CsCCD2L，CsCCD2的一个长转录本）会影响玉米黄质含量和耐光性。在藏红花中，CsCCD2L在其整个生命周期中有所变化，影响玉米黄质含量。藏红花在室内开花，其叶子仍包裹在鞘状叶中。CsCCD2L在藏红花叶子中的表达在开花当天达到峰值，但在营养阶段叶子从鞘状叶中伸展出来进行光合作用时显著下降。此阶段的强光会导致叶子变黄、CsCCD2L表达降低以及玉米黄质含量增加。这些结果表明CsCCD2L调节玉米黄质含量和耐光性。此外，CsCCD2L在橙色柱头中表达最高。对橙色柱头阶段的花芽进行强光处理会显著降低成熟柱头中的藏红花素含量。总的来说，这些结果不仅揭示了藏红花独特的生长模式，还为通过精确控制光照强度和CsCCD2L的表达来提高藏红花品质提供了有前景的途径。
