Contribuição por estudos metabolômicos por HPLC-DAD-MS/MS para compreenção da influência do estresse de alagamento no metabolismo especializado de soja

Abstract

Soybean (Glycine max, Leguminosae) is one of the most important crops cultivated and traded worldwide. However, environmental changes (that cannot be controlled) have a significant and negative impact on its quality and productivity. One of the most difficult conditions to manage is the water stress, which has become more common due to the increasing incidence of climatic phenomena such as El Niño and La Niña. Therefore, knowing the strategies used by soybeans to adapt to these threats is essential for developing cultivars with better performance, since changes in plant metabolism are part of the initial responses to stress. In soybeans, many genes related to the isoflavonoids biosynthetic pathway are up-regulated in response to pathogen attack. However, there is not much evidence available on the induction and accumulation of these metabolites under abiotic stresses, and even less under water stresses. Therefore, the aim of this research was to comprehensively how the biosynthetic pathway of isoflavones and phytoalexins in soybeans responds to waterlogging. In the present study, four soybean genotypes were grown under control and waterlogged conditions. Leaf and root extracts were subjected to metabolomics analysis using HPLC-DAD-ESI-QTOF-MS/MS. The results were significant in the roots, showing a statistically significant reduction in the precursor glycinol, and subsequent accumulation of gliceolidins. Gliceolins, which are the end products of phytoalexin biosynthesis, were reduced under waterlogging. The glycosylated isoflavone daidzin was significantly accumulated in the leaves, with subsequent accumulation of gliceolins in the roots. The results shed light on the important changes in the expression of isoflavone biosynthetic pathway metabolites and phytoalexins in soybeans in response to waterlogging.