Modulação metabólica em variedades contrastantes de sorgo induzidas pelo estresse do retículo endoplasmático

Abstract

Sorghum (Sorghum bicolor (L.) Moench) is an important cereal crop native to the African continent and belonging to the Poaceae family. It is considered the fifth most-produced cereal in the world and, from the agronomic point of view, this growth is mainly explained by the high potential of grain production and dry matter of the crop. However, like any living organism, sorghum can be affected by abiotic and biotic stresses that compromise its productivity. Several responses to unfavorable conditions are modulated by plants, such as morphophysiological and molecular adjustments, in addition to the induction of the poorly unfold protein response pathway that occurs in the endoplasmic reticulum (ER). In fact, ER presents itself as a key organelle for the survival of plants in the face of stress. Thus, a review was developed that includes advances in the knowledge of the ER response induced by treatments with tunicamycin (TM) and dithiothreitol (DTT), especially their physiological effects downstream in order to help elucidate possible mechanisms of adjustment to environmental stresses from the mechanisms of adaptation for survival or death. Then, to complement the understanding of the various responses used in the face of stresses, a study was carried out involving metabolomics, multidisciplinary science that offers unique possibilities to decode metabolic modulations through an approach that goes beyond the transcriptome and the proteome. The efficiency of the ER in dealing with the accumulation of poorly folded proteins is fundamental for the survival of the plants in any situation of stress. Therefore, it is relevant to identify genotypes that present different physiological, biochemical, and molecular responses in relation to the levels of sensitivity to stress. Therefore, the aim of this research was to evaluate changes in the metabolic profiles of two varieties of sorghum seedlings, CSF18 and CSF20, under endoplasmic reticulum (ER) stress-induced by increasing tunicamycin concentrations. The results showed that stress-induced a reduction in growth, mainly of the root. The lower concentration of TM induced the highest lipid peroxidation of both varieties. The Score plot results indicated a separation of the TM treatments with control There was a negative modulation of key metabolites in CSF18 and a positive modulation of them in CSF20, which performed better in the face of stress, related to a significant increase in carbohydrates and organic acids.