Szepesi Ágnes, Poór Péter, Bakacsy László
Department of Plant Biology, Faculty of Science and Informatics, Institute of Biology, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary.
Plants (Basel). 2022 Jun 24;11(13):1670. doi: 10.3390/plants11131670.
The phytohormone salicylic acid (SA) can influence the polyamine metabolism in plants. Additionally, polyamines (PAs) can regulate the synthesis of SA, providing an exciting interplay between them not only in plant growth and development but also in biotic or abiotic stress conditions. The effect of SA on polyamine metabolism of leaves is well-studied but the root responses are rarely investigated. In this study, tomato roots were used to investigate the effect of short-term exposition of SA in two different concentrations, a sublethal 0.1 mM and a lethal 1 mM. To explore the involvement of SA in regulating PAs in roots, the degradation of PAs was also determined. As both SA and PAs can induce reactive oxygen species (ROS) and nitric oxide (NO) production, the balance of ROS and NO was analyzed in root tips. The results showed that 0.1 mM SA induced the production of higher PAs, spermidine (Spd), and spermine (Spm), while 1 mM SA decreased the PA contents by activating degrading enzymes. Studying the ROS and NO levels in root tips, the ROS production was induced earlier than NO, consistent with all the investigated zones of roots. This study provides evidence for concentration-dependent rapid effects of SA treatments on polyamine metabolism causing an imbalance of ROS-NO in root tips.
植物激素水杨酸（SA）能够影响植物体内的多胺代谢。此外，多胺（PAs）可以调节SA的合成，这不仅在植物生长发育过程中，而且在生物或非生物胁迫条件下，都使它们之间呈现出一种有趣的相互作用。SA对叶片多胺代谢的影响已得到充分研究，但对根部反应的研究却很少。在本研究中，利用番茄根来研究两种不同浓度SA短期处理的效果，一种是亚致死浓度0.1 mM，另一种是致死浓度1 mM。为了探究SA在调节根部多胺中的作用，还测定了多胺的降解情况。由于SA和多胺都能诱导活性氧（ROS）和一氧化氮（NO）的产生，因此分析了根尖中ROS和NO的平衡。结果表明，0.1 mM SA诱导了更高水平的多胺亚精胺（Spd）和精胺（Spm）的产生，而1 mM SA通过激活降解酶降低了多胺含量。研究根尖中的ROS和NO水平发现，ROS的产生比NO更早被诱导，这与所有研究的根区情况一致。本研究为SA处理对多胺代谢的浓度依赖性快速影响提供了证据，这种影响导致根尖中ROS-NO失衡。
