Wang Pu, Zhang Hong, Yin Yongli, Ge Yue, Chen Binrui, Hu Jing, Wang Yu, Ni Dejiang, Guo Fei
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China.
Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China.
Genome Biol. 2025 Jun 2;26(1):150. doi: 10.1186/s13059-025-03618-2.
There is a Chinese proverb that good tea comes from high mountains with clouds and mists, suggesting the important impact of environmental factors on the development and secondary metabolism in tea plants. However, the epigenetic mechanism involved is still unclear.
High altitude results in light enhancement with a higher retention of short-wavelength light in cloudy conditions, suggesting the key role of short-wavelength light in the quality formation of tea plants. Thus, we focus on the representative short-wavelength light, blue and UV-A, and characterize plant responses in epigenome, transcriptome, leaf development, and metabolome. We profile six histone modifications under different light wavelengths and link these to leaf development and secondary metabolism, including changes in gene expression during flavonoid, theanine, caffeine, and β-carotene biosynthesis. There is higher stomatal density and thicker mesophyll tissues under blue light, with higher levels of chlorophyll components under UV-A light. The epigenome results in differential changes of stomatal density and quality components in different light conditions. We further identify crucial histone modifications in leaf development and secondary metabolism. Functional analyses suggest diverse regulations mediated by cryptochrome and phototropin in light adaptation, and we confirm the important role of CsSDG36-mediated histone H3K4 methylation.
Our results not only reveal the landscape of histone modifications, transcripts, leaf development, and metabolites from different lights in tea plants, but also provide insight into the roles of photoreceptors and epigenetic mechanisms involved in leaf development and secondary metabolism.
中国有句谚语叫“高山云雾出好茶”，这表明环境因素对茶树的生长发育和次生代谢有着重要影响。然而，其中涉及的表观遗传机制仍不清楚。
高海拔导致光照增强，在多云条件下短波长光的保留率更高，这表明短波长光在茶树品质形成中起关键作用。因此，我们聚焦于具有代表性的短波长光，即蓝光和UV-A，并对植物在表观基因组、转录组、叶片发育和代谢组方面的反应进行了表征。我们分析了不同光波长下的六种组蛋白修饰，并将这些修饰与叶片发育和次生代谢联系起来，包括黄酮类化合物、茶氨酸、咖啡因和β-胡萝卜素生物合成过程中的基因表达变化。蓝光下气孔密度更高，叶肉组织更厚，UV-A光下叶绿素成分含量更高。表观基因组结果导致不同光照条件下气孔密度和品质成分的差异变化。我们进一步确定了叶片发育和次生代谢中关键的组蛋白修饰。功能分析表明，隐花色素和向光素在光适应过程中介导了多种调控，并且我们证实了CsSDG36介导的组蛋白H3K4甲基化的重要作用。
我们的研究结果不仅揭示了茶树在不同光照下的组蛋白修饰、转录本、叶片发育和代谢物情况，还深入了解了光感受器以及参与叶片发育和次生代谢的表观遗传机制的作用。
