Abstract:
In plants, secondary metabolites change in response to environmental conditions. These changes co-regulate resilience to stressful environmental conditions, plant growth and development, and interactions between plants and the wider ecosystem, while also affecting soil carbon storage and atmospheric and climatic conditions. The objective of this study was to determine the association between UV exposure and the contents of key metabolites, including amino acids, phenolics, flavonoids, terpenoids, carotenoids, tocopherols, and phytosterols. Mentha spicata plantlets were grown in tissue culture boxes for 30 days and then exposed to a low dose of broadband UV-B (291-315 nm; 2.8 kJm-2 biologically effective UV) enriched light for eight days. Metabolite contents were quantified either immediately after the final UV exposure, or after seven days of recovery under photosynthetically active radiation. It was found that UV promoted the production of flavonoids (1.8-fold) ahead of phenolic acids (unchanged). Furthermore, the majority of monoterpenes and sesquiterpenes, constituents of valuable mint essential oil, were significantly increased through UV treatment (up to 90-fold for α-linalool). In contrast, the contents of carotenoids and tocopherols did not increase following UV exposure. A comparison between plants sampled immediately after UV exposure and after seven days of recovery showed that there was an overall increase in the content of carotenoids, mono- and sesquiterpenes, phenolics, and amino acids following recovery, while the contents of sterols and tocopherols decreased. These UV-induced changes in metabolite profile may have important consequences for agriculture, ecology, and even the global climate, and they also provide an exciting opportunity to enhance crop value, facilitating the development of improved products with higher levels of essential oils and added benefits of enhanced flavour, colour, and bioactive content.
摘要:
在植物中,次生代谢物随环境条件而变化。这些变化共同调节对压力环境条件的适应能力,植物生长发育,以及植物和更广泛的生态系统之间的相互作用,同时也会影响土壤碳储量以及大气和气候条件。本研究的目的是确定紫外线暴露与关键代谢物含量之间的关联,包括氨基酸,酚类物质,黄酮类化合物,萜类化合物,类胡萝卜素,生育酚,和植物甾醇。将Menthaspicata小植株在组织培养箱中生长30天,然后暴露于低剂量的宽带UV-B(291-315nm;2.8kJm-2生物有效UV)富集光下八天。在最终的紫外线暴露后立即对代谢物含量进行定量,或在光合有效辐射下恢复七天后。发现紫外线促进黄酮类化合物的产生(1.8倍)领先于酚酸(不变)。此外,大多数单萜和倍半萜,有价值的薄荷精油的成分,通过紫外线处理显着增加(α-芳樟醇高达90倍)。相比之下,紫外线照射后,类胡萝卜素和生育酚的含量没有增加。紫外线照射后立即取样和恢复七天后取样的植物之间的比较表明,类胡萝卜素的含量总体上有所增加,单萜和倍半萜,酚类物质,和氨基酸回收后,而甾醇和生育酚的含量下降。这些紫外线诱导的代谢物分布变化可能对农业产生重要影响,生态学,甚至全球气候,它们也提供了一个令人兴奋的机会来提高作物价值,促进开发具有更高水平精油和增强风味的附加益处的改进产品,颜色,和生物活性含量。