Abstract：
Plants trigger endoplasmic reticulum (ER) pathways to survive stresses, but the assistance of ER in plant tolerance still needs to be explored. Thus, we selected sensitive and tolerant contrasting abiotic stress sorghum varieties to test if they present a degree of tolerance to ER stress. Accordingly, this work evaluated crescent concentrations of tunicamycin (TM µg mL-1): control (0), lower (0.5), mild (1.5), and higher (2.5) on the initial establishment of sorghum seedlings CSF18 and CSF20. ER stress promoted growth and metabolism reductions, mainly in CSF18, from mild to higher TM. The lowest TM increased SbBiP and SbPDI chaperones, as well as SbbZIP60, and SbbIRE1 gene expressions, but mild and higher TM decreased it. However, CSF20 exhibited higher levels of SbBiP and SbbIRE1 transcripts. It corroborated different metabolic profiles among all TM treatments in CSF18 shoots and similarities between profiles of mild and higher TM in CSF18 roots. Conversely, TM profiles of both shoots and roots of CSF20 overlapped, although it was not complete under low TM treatment. Furthermore, ER stress induced an increase of carbohydrates (dihydroxyacetone in shoots, and cellobiose, maltose, ribose, and sucrose in roots), and organic acids (pyruvic acid in shoots, and butyric and succinic acids in roots) in CSF20, which exhibited a higher degree of ER stress tolerance compared to CSF18 with the root being the most affected plant tissue. Thus, our study provides new insights that may help to understand sorghum tolerance and the ER disturbance as significant contributor for stress adaptation and tolerance engineering.
摘要：
植物触发内质网（ER）途径以生存压力，但ER对植物耐受性的帮助仍有待探索。因此，我们选择了敏感和耐受的对比非生物胁迫高粱品种来测试它们是否对ER胁迫具有一定程度的耐受性。因此，这项工作评估了衣霉素的新月浓度（TMµgmL-1）：对照（0），较低（0.5），轻度（1.5），高粱幼苗CSF18和CSF20的初始建立较高（2.5）。ER应激促进生长和代谢减少，主要在CSF18，从轻度到较高的TM。最低的TM增加了SbBiP和SbPDI伴侣，以及SbbZIP60和SbbIRE1基因表达，但轻度和较高的TM降低了它。然而,CSF20表现出更高水平的SbBiP和SbbIRE1转录物。它证实了CSF18芽中所有TM处理之间的不同代谢谱，以及CSF18根中轻度和较高TM谱之间的相似性。相反，CSF20的芽和根的TM剖面重叠，尽管在低TM治疗下并不完全。此外，内质网应激诱导碳水化合物增加（枝条中的二羟基丙酮，和纤维二糖，麦芽糖,核糖,和根中的蔗糖)，和有机酸（芽中的丙酮酸，和根中的丁酸和琥珀酸）在CSF20中，与CSF18相比，表现出更高的ER胁迫耐受性，其中根是受影响最大的植物组织。因此，我们的研究提供了新的见解，可能有助于理解高粱耐受性和内质网干扰是应激适应和耐受性工程的重要因素。
