Agricultural Institute, Centre for Agricultural Research, 2462 Martonvásár, Brunszvik 2, Hungary.
Int J Mol Sci. 2020 Mar 12;21(6):1942. doi: 10.3390/ijms21061942.
The exposure of plants to non-lethal low temperatures may increase their tolerance to a subsequent severe chilling stress. To some extent, this is also true for cold-sensitive species, including maize. In the present work, based on our previous microarray experiment, the differentially expressed genes with phenylpropanoid pathways in the focus were further investigated in relation to changes in certain phenolic compounds and other plant growth regulators. Phenylalanine ammonia lyase (PAL) was mainly activated under limited light conditions. However, light-induced anthocyanin accumulation occurred both in the leaves and roots. Chilling stress induced the accumulation of salicylic acid (SA), but this accumulation was moderated in the cold-acclimated plants. Acclimation also reduced the accumulation of jasmonic acid (JA) in the leaves, which was rather induced in the roots. The level of abscisic acid (ABA) is mainly related to the level of the stress, and less indicated the level of the acclimation. The highest glutathione (GSH) amount was observed during the recovery period in the leaves of plants that were cold acclimated at growth light, while their precursors started to accumulate GSH even during the chilling. In conclusion, different light conditions during the cold acclimation period differentially affected certain stress-related mechanisms in young maize plants and changes were also light-dependent in the root, not only in the leaves.
植物暴露在非致死性低温下可能会增加它们对随后严重冷胁迫的耐受性。在某种程度上，这对包括玉米在内的冷敏感物种也是如此。在本工作中，基于我们之前的基因芯片实验，进一步研究了苯丙烷途径中差异表达的基因与某些酚类化合物和其他植物生长调节剂的变化之间的关系。苯丙氨酸解氨酶（PAL）主要在光照不足的条件下被激活。然而，光照诱导的花青素积累既发生在叶片中，也发生在根中。冷胁迫诱导水杨酸（SA）的积累，但在经过低温驯化的植物中，这种积累得到了调节。驯化还减少了叶片中茉莉酸（JA）的积累，而 JA 在根中被诱导增加。脱落酸（ABA）的水平主要与胁迫水平有关，而与驯化水平的关系较小。在生长光下进行低温驯化的植物叶片在恢复期观察到的谷胱甘肽（GSH）含量最高，而其前体甚至在冷藏期间就开始积累 GSH。总之，低温驯化期间不同的光照条件对幼玉米植株的某些与应激相关的机制产生了不同的影响，而且这种变化在根中也是依赖光照的，而不仅仅在叶片中。
