Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
Doctoral School of Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
Biomolecules. 2020 Jul 10;10(7):1031. doi: 10.3390/biom10071031.
Endoplasmic reticulum (ER) stress elicits a protective mechanism called unfolded protein response (UPR) to maintain cellular homeostasis, which can be regulated by defence hormones. In this study, the physiological role of jasmonic acid (JA) in ER stress and UPR signalling has been investigated in intact leaves of tomato plants. Exogenous JA treatments not only induced the transcript accumulation of UPR marker gene but also elevated transcript levels of and . By the application of JA signalling mutant plants, the role of JA in ER stress sensing and signalling was further investigated. Treatment with tunicamycin (Tm), the inhibitor of N-glycosylation of secreted glycoproteins, increased the transcript levels of . Interestingly, and were significantly lower in . In contrast, the transcript accumulation of () and was higher in . To evaluate how a chemical chaperone modulates Tm-induced ER stress, plants were treated with sodium 4-phenylbutyrate, which also decreased the Tm-induced increase in , and transcripts. In addition, it was found that changes in hydrogen peroxide content, proteasomal activity, and lipid peroxidation induced by Tm is regulated by JA, while nitric oxide was not involved in ER stress and UPR signalling in leaves of tomato.
内质网（ER）应激会引发一种称为未折叠蛋白反应（UPR）的保护机制，以维持细胞内稳态，这种机制可以被防御激素调节。在本研究中，研究了茉莉酸（JA）在番茄植株完整叶片中的 ER 应激和 UPR 信号转导中的生理作用。外源 JA 处理不仅诱导了 UPR 标记基因的转录积累 ，还提高了 和 的转录水平 。通过应用 JA 信号突变体 植物，进一步研究了 JA 在 ER 应激感应和信号转导中的作用。用衣霉素（Tm）处理，一种抑制分泌糖蛋白 N-糖基化的抑制剂，增加了 的转录水平 。有趣的是， 和 在 中明显较低 。相比之下， 和 的转录积累在 中更高 。为了评估化学伴侣如何调节 Tm 诱导的 ER 应激，用 4-苯丁酸钠处理植物，这也降低了 Tm 诱导的 、 和 转录物的增加。此外，发现 Tm 诱导的过氧化氢含量、蛋白酶体活性和脂质过氧化的变化受 JA 调节，而 NO 不参与番茄叶片中的 ER 应激和 UPR 信号转导。
