Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Kraków, Poland.
Physiol Plant. 2024 Nov-Dec;176(6):e14583. doi: 10.1111/ppl.14583.
The presented study aims to elucidate the regulatory role of Pipecolic acid (Pip) in modulating the antioxidant system activity of Mesembryanthemum crystallinum plants exposed to Pseudomonas syringae infestation. M. crystallinum, known for its semi-halophytic nature, can transition its metabolism from C to CAM under salt stress conditions. The research encompasses the antioxidant system of the plants, covering both enzymatic and low molecular weight components. The findings indicate that Pip supplementation confers a beneficial effect on certain elements of the antioxidant system when the plants are subjected to stress induced by bacteria. Notably, during critical periods, particularly in the initial days post-bacterial treatment, M. crystallinum plants supplemented with Pip and exhibiting C metabolism display heightened total antioxidant capacity. This enhancement includes increased superoxide dismutase activity and elevated levels of glutathione and proline. However, in plants with salinity-induced CAM, where these parameters are naturally higher, the supplementation of Pip does not yield significant effects. These results validate the hypothesis that the regulatory influence of Pip on defence mechanisms against biotic stress is contingent upon the metabolic state of the plant. Furthermore, this regulatory effect is more pronounced in C plants of M. crystallinum than those undergoing CAM metabolism induced by salinity stress.
本研究旨在阐明吡咯啉酸（Pip）在调节受丁香假单胞菌侵染的马齿苋植物抗氧化系统活性中的调节作用。马齿苋因其半盐生性质而闻名，在盐胁迫条件下可以将其代谢从 C 型转变为 CAM 型。该研究涵盖了植物的抗氧化系统，包括酶和低分子量成分。研究结果表明，在植物受到细菌诱导的胁迫时，Pip 补充剂对某些抗氧化系统元素具有有益的影响。值得注意的是，在关键时期，特别是在细菌处理后的最初几天，表现出 C 代谢的补充 Pip 的马齿苋植物显示出更高的总抗氧化能力。这种增强包括超氧化物歧化酶活性的增加以及谷胱甘肽和脯氨酸水平的升高。然而，在盐诱导的 CAM 植物中，这些参数自然较高，Pip 的补充并没有产生显著的效果。这些结果验证了这样一个假设，即 Pip 对防御机制的调节作用取决于植物的代谢状态。此外，这种调节作用在 C 型马齿苋植物中比在盐胁迫诱导的 CAM 代谢植物中更为明显。
