Blue light plays an important role in most plant functions: it influences plant morphology, photosynthesis, primary and secondary metabolism. Although certain studies have already revealed that blue light may have positive effects under certain stress conditions, its exact mechanism is largely unknown. The importance of polyamines in stress tolerance has been widely investigated; however, their interaction with the dependent processes is still poorly understood. In addition, the quality of light can also affect the polyamine metabolism, thus it can influence their roles and relationships with other protective compounds. According to these, the main question of the present work was that whether blue light induces different responses during Cd stress, especially which are related to polyamine metabolism, and whether it may be able to modify the protective effect of exogenous putrescine compared to white light conditions in wheat. It has been demonstrated that less pronounced Cd stress was detected under blue light than at white light conditions. Blue light had its own effect at metabolite and gene expression levels and the lower Cd uptake was accompanied by lower phytochelatin but higher conjugated polyamine accumulation at the same time. Putrescine pre-treatment had protective effect especially under white light conditions, and it highlighted certain differences observed under Cd stress between blue light and white light conditions, especially in phytochelatin synthesis, polyamine metabolism, and accumulation of phenolic compounds and plant hormones. Our data demonstrated that blue light regulated Cd tolerance in wheat and modified defence strategy when excess putrescine was present.

中文翻译：

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小麦中腐胺预处理对白光或蓝光下镉胁迫反应的影响

蓝光在大多数植物功能中发挥着重要作用：它影响植物形态、光合作用、初级和次生代谢。尽管某些研究已经表明蓝光在某些压力条件下可能具有积极作用，但其确切机制尚不清楚。多胺在应激耐受性中的重要性已被广泛研究。然而，它们与依赖进程的相互作用仍然知之甚少。此外，光的质量也会影响多胺的代谢，从而影响它们的作用以及与其他保护性化合物的关系。据此，本工作的主要问题是蓝光是否在镉胁迫期间诱导不同的反应，特别是与多胺代谢相关的反应，以及与白光条件相比，蓝光是否能够改变外源腐胺的保护作用在小麦中。已经证明，在蓝光条件下检测到的镉应力比在白光条件下检测到的镉应力不太明显。蓝光对代谢物和基因表达水平有其自身的影响，较低的镉吸收伴随着较低的植物螯合素，但同时较高的共轭多胺积累。腐胺预处理尤其在白光条件下具有保护作用，并且突出了蓝光和白光条件下镉胁迫下观察到的某些差异，特别是在植物螯合素合成、多胺代谢以及酚类化合物和植物激素的积累方面。我们的数据表明，蓝光调节小麦的镉耐受性，并在存在过量腐胺时修改防御策略。