Plant Cell Biotechnology Department, CSIR-Central Food Technological Research Institute, Mysore 570020, India.
Department of Biochemistry, Karnatak University, Dharward, India.
Food Res Int. 2018 Sep;111:11-19. doi: 10.1016/j.foodres.2018.04.040. Epub 2018 Apr 19.
Coriander (Coriandrum sativum L.), a commonly used annual herb that accumulates carotenoids upon methyl jasmonate (MeJA) treatment, provides an excellent model to investigate carotenogenesis and gene regulation. To explore key mechanisms involved in enhancing carotenoids, transcriptional expression profile of ten carotenogenic genes in the presence of MeJA and various gene specific inhibitors were investigated. Foliar application of MeJA (10 μM) increased expression levels of CsPDS (phytoene desaturase), CsZDS (ς-carotene desaturase), CsCHYE (carotene ε - hydroxylase) and CsLCYE (lycopene β-cyclase) genes, and their transcript levels were strongly associated with carotenoid content, where, three days after treatment, 3.9 & 6.1 fold increase was observed for β-carotene and lutein respectively. The regulatory effect of key genes, CsPDS, CsZDS, CsLCYE and LCYB were further confirmed by using gene-specific inhibitors fosmidomycin, norflurazon and amitrol. Norflurazon- the phytoene desaturation inhibitor leads to a decrease in β-carotene and lutein content correlated with CsPDS, CsZDS gene induction. Our results clearly demonstrate that MeJA induced-signalling network evokes carotenogenic genes, leading to the accumulation of carotenoids. This knowledge may help to develop precise strategies for remodelling carotenoid pathway so that desired levels of a particular carotenoid in leafy vegetables is achievable.
芫荽（Coriandrum sativum L.）是一种常用的一年生草本植物，用茉莉酸甲酯（MeJA）处理后会积累类胡萝卜素，是研究类胡萝卜素生物合成和基因调控的理想模型。为了探讨增强类胡萝卜素的关键机制，研究了在 MeJA 存在下和各种基因特异性抑制剂存在下的十个类胡萝卜素生物合成基因的转录表达谱。叶喷 MeJA（10 μM）增加了 CsPDS（phytoene desaturase）、CsZDS（ς-carotene desaturase）、CsCHYE（carotene ε - hydroxylase）和 CsLCYE（lycopene β-cyclase）基因的表达水平，其转录水平与类胡萝卜素含量密切相关，处理后 3 天，β-胡萝卜素和叶黄素分别增加了 3.9 倍和 6.1 倍。使用基因特异性抑制剂 fosmidomycin、norflurazon 和 amitrol 进一步证实了关键基因 CsPDS、CsZDS、CsLCYE 和 LCYB 的调节作用。作为类胡萝卜素生物合成抑制剂的 norflurazon 导致 β-胡萝卜素和叶黄素含量下降，与 CsPDS、CsZDS 基因诱导相关。我们的研究结果清楚地表明，MeJA 诱导的信号网络会引发类胡萝卜素生物合成基因的表达，导致类胡萝卜素的积累。这一知识可能有助于制定精确的策略来重塑类胡萝卜素途径，从而在叶菜类蔬菜中实现特定类胡萝卜素的预期水平。
