College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan, 467036, Henan, China.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
BMC Plant Biol. 2022 Dec 12;22(1):577. doi: 10.1186/s12870-022-03958-2.
Taxus is a rare gymnosperm plant that is the sole producer of the anticancer drug paclitaxel. The growth and development of Taxus is affected by environmental factors such as light. However, little is known about how light conditions affect growth and metabolic processes, especially paclitaxel biosynthesis.
In this study, we applied three different light conditions to Taxus chinensis young saplings and investigated the physiological response and gene expression. Our observations showed that exposure to high light led to oxidative stress, caused photoinhibition, and damaged the photosynthetic systems in T. chinensis. The paclitaxel content in T. chinensis leaves was significantly decreased after the light intensity increased. Transcriptomic analysis revealed that numerous genes involved in paclitaxel biosynthesis and phenylpropanoid metabolic pathways were downregulated under high light. We also analyzed the expression of JA signaling genes, bHLH, MYB, AP2/ERF transcription factors, and the CYP450 families that are potentially related to paclitaxel biosynthesis. We found that several CYP450s, MYB and AP2/ERF genes were induced by high light. These genes may play an important role in tolerance to excessive light or heat stress in T. chinensis.
Our study elucidates the molecular mechanism of the effects of light conditions on the growth and development of T. chinensis and paclitaxel biosynthesis, thus facilitating the artificial regeneration of Taxus and enhancing paclitaxel production.
红豆杉是一种稀有的裸子植物，是抗癌药物紫杉醇的唯一生产者。红豆杉的生长和发育受到光等环境因素的影响。然而，对于光照条件如何影响生长和代谢过程，特别是紫杉醇生物合成，知之甚少。
本研究应用三种不同的光照条件处理南方红豆杉幼树，研究其生理响应和基因表达。我们的观察表明，高光导致氧化应激，引起光抑制，并损伤南方红豆杉的光合系统。光照强度增加后，南方红豆杉叶片中的紫杉醇含量显著下降。转录组分析表明，高光下参与紫杉醇生物合成和苯丙烷代谢途径的许多基因下调。我们还分析了与紫杉醇生物合成相关的茉莉酸信号基因、bHLH、MYB、AP2/ERF 转录因子和 CYP450 家族的表达。我们发现，一些 CYP450s、MYB 和 AP2/ERF 基因被高光诱导。这些基因可能在南方红豆杉对过量光照或热应激的耐受中发挥重要作用。
本研究阐明了光照条件对南方红豆杉生长发育和紫杉醇生物合成的影响的分子机制，从而有助于红豆杉的人工再生和提高紫杉醇的产量。
