College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, Shandong, 271018, People's Republic of China.
Institute of Shandong River Wetlands, Jinan, Shandong, 271100, People's Republic of China.
BMC Plant Biol. 2021 Nov 23;21(1):557. doi: 10.1186/s12870-021-03325-7.
Arabidopsis protein disulfide isomerase 1 (AtPDI1) has been demonstrated to have disulfide isomerase activity and to be involved in the stress response. However, whether the anti-stress function is directly related to the activities of thiol-disulfide exchange remains to be elucidated.
In the present study, encoding sequences of AtPDI1 of wild-type (WT) and double-cysteine-mutants were transformed into an AtPDI1 knockdown Arabidopsis line (pdi), and homozygous transgenic plants named pdi-AtPDI1, pdi-AtPDI1 and pdi-AtPDI1 were obtained. Compared with the WT and pdi-AtPDI1, the respective germination ratios of pdi-AtPDI1 and pdi-AtPDI1 were significantly lower under abiotic stresses and exogenous ABA treatment, whereas the highest germination rate was obtained with AtPDI1 overexpression in the WT (WT- AtPDI1). The root length among different lines was consistent with the germination rate; a higher germination rate was observed with a longer root length. When seedlings were treated with salt, drought, cold and high temperature stresses, pdi-AtPDI1, pdi-AtPDI1 and pdi displayed lower survival rates than WT and AtPDI1 overexpression plants. The transcriptional levels of ABA-responsive genes and genes encoding ROS-quenching enzymes were lower in pdi-AtPDI1 and pdi-AtPDI1 than in pdi-AtPDI1.
Taken together, these results clearly suggest that the anti-stress function of AtPDI1 is directly related to the activity of disulfide isomerase.
拟南芥蛋白二硫键异构酶 1（AtPDI1）已被证明具有二硫键异构酶活性，并参与应激反应。然而，其抗应激功能是否与巯基-二硫键交换的活性直接相关仍有待阐明。
本研究将野生型（WT）和双半胱氨酸突变体的 AtPDI1 编码序列转化到 AtPDI1 敲低拟南芥系（pdi）中，获得了纯合转基因植株，分别命名为 pdi-AtPDI1、pdi-AtPDI1 和 pdi-AtPDI1。与 WT 和 pdi-AtPDI1 相比，在非生物胁迫和外源 ABA 处理下，pdi-AtPDI1 和 pdi-AtPDI1 的各自萌发率显著降低，而在 WT 中过表达 AtPDI1 则获得了最高的萌发率（WT-AtPDI1）。不同品系间的根长与萌发率一致；根长较长的萌发率较高。当幼苗受到盐、干旱、寒冷和高温胁迫时，pdi-AtPDI1、pdi-AtPDI1 和 pdi 的存活率低于 WT 和过表达 AtPDI1 的植物。与 pdi-AtPDI1 相比，pdi-AtPDI1 和 pdi-AtPDI1 中的 ABA 响应基因和编码 ROS 清除酶的基因的转录水平较低。
综上所述，这些结果清楚地表明，AtPDI1 的抗应激功能与二硫键异构酶的活性直接相关。
