Coutinho Flaviane Silva, Dos Santos Danilo Silva, Lima Lucas Leal, Vital Camilo Elber, Santos Lázaro Aleixo, Pimenta Maiana Reis, da Silva João Carlos, Ramos Juliana Rocha Lopes Soares, Mehta Angela, Fontes Elizabeth Pacheco Batista, de Oliveira Ramos Humberto Josué
1Laboratory of Plant Molecular Biology, Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, BIOAGRO/INCT-IPP, Viçosa, MG Brazil.
2Center of Analyses of Biomolecules, NuBioMol, Universidade Federal de Viçosa, Viçosa, MG Brazil.
Physiol Mol Biol Plants. 2019 Mar;25(2):457-472. doi: 10.1007/s12298-019-00643-x. Epub 2019 Feb 14.
Drought is one of major constraints that limits agricultural productivity. Some factors, including climate changes and acreage expansion, indicates towards the need for developing drought tolerant genotypes. In addition to its protective role against endoplasmic reticulum (ER) stress, we have previously shown that the molecular chaperone binding protein (BiP) is involved in the response to osmotic stress and promotes drought tolerance. Here, we analyzed the proteomic and metabolic profiles of BiP-overexpressing transgenic soybean plants and the corresponding untransformed line under drought conditions by 2DE-MS and GC/MS. The transgenic plant showed lower levels of the abscisic acid and jasmonic acid as compared to untransformed plants both in irrigated and non-irrigated conditions. In contrast, the level of salicylic acid was higher in transgenic lines than in untransformed line, which was consistent with the antagonistic responses mediated by these phytohormones. The transgenic plants displayed a higher abundance of photosynthesis-related proteins, which gave credence to the hypothesis that these transgenic plants could survive under drought conditions due to their genetic modification and altered physiology. The proteins involved in pathways related to respiration, glycolysis and oxidative stress were not signifcantly changed in transgenic plants as compared to untransformed genotype, which indicate a lower metabolic perturbation under drought of the engineered genotype. The transgenic plants may have adopted a mechanism of drought tolerance by accumulating osmotically active solutes in the cell. As evidenced by the metabolic profiles, the accumulation of nine primary amino acids by protein degradation maintained the cellular turgor in the transgenic genotype under drought conditions. Thus, this mechanism of protection may cause the physiological activities including photosynthesis to be active under drought conditions.
干旱是限制农业生产力的主要制约因素之一。包括气候变化和种植面积扩大在内的一些因素表明，有必要培育耐旱基因型。除了其对内质网（ER）应激的保护作用外，我们之前还表明分子伴侣结合蛋白（BiP）参与渗透胁迫反应并促进耐旱性。在这里，我们通过二维电泳-质谱（2DE-MS）和气相色谱-质谱（GC/MS）分析了干旱条件下过表达BiP的转基因大豆植株及其相应未转化品系的蛋白质组和代谢谱。在灌溉和非灌溉条件下，转基因植株的脱落酸和茉莉酸水平均低于未转化植株。相反，转基因品系中水杨酸水平高于未转化品系，这与这些植物激素介导的拮抗反应一致。转基因植株中光合作用相关蛋白的丰度更高，这支持了这样一种假设，即这些转基因植株由于其基因改造和生理变化能够在干旱条件下存活。与未转化基因型相比，转基因植株中参与呼吸、糖酵解和氧化应激相关途径的蛋白质没有显著变化，这表明工程基因型在干旱条件下的代谢扰动较小。转基因植株可能通过在细胞中积累渗透活性溶质来采用耐旱机制。代谢谱表明，在干旱条件下，通过蛋白质降解积累的9种必需氨基酸维持了转基因基因型中的细胞膨压。因此，这种保护机制可能使包括光合作用在内的生理活动在干旱条件下保持活跃。
