Strong relationship between elemental stoichiometry and metabolome in plants

Abstract

Shifts in the elemental stoichiometry of organisms in response to their ontogeny and to changing environmental conditions should be related to metabolomic changes because elements operate mostly as parts of molecular compounds. Here we show this relationship in leaves of Erica multiflora throughout their seasonal development and in response to moderate experimental field conditions of drought and warming. The N/P ratio in leaves decreased in the metabolically active growing seasons, coinciding with an increase in the content of primary metabolites. These results support the growthrate hypothesis that states that rapidly growing organisms present low N/P ratios because of the increase in allocation of P to RNA. The foliar N/K and P/K ratios were lower in summer and in the drought treatment, in accordance with the role of K in osmotic protection, and coincided with the increase of compounds related to the avoidance of water stress. These results provide strong evidence of the relationship between the changes in foliar C/N/P/K stoichiometry and the changes in the leaf's metabolome during plant growth and environmental stress. Thus these results represent a step in understanding the relationships between stoichiometry and an organism's lifestyle.climate change | metabolomics | ecometabolomics | Mediterranean climate

Human-induced nitrogen–phosphorus imbalances alter natural and managed ecosystems across the globe

“…The observed metabolic shifts associated with organisms N:P ratio change 21 provide support for the hypothesis that exceedances of the optimal N:P ratios can reduce growth rates 34 . Several studies have verified this hypothesis in diverse unicellular organisms, zooplankton and fish in aquatic ecosystems; there is evidence that this hypothesis can also be extended to a large number of terrestrial plants and animals, albeit with a few exceptions 35 (Fig.…”

“…In the Mediterranean shrub Erica multiflora, for instance, increases in N:P ratio were accompanied by decreased proportions of primary metabolites (sugars, amino acids) relative to lipids and secondary metabolites, and also by lower growth rates 21 . Several studies have observed that the N:P ratio of foliage correlates negatively with net photosynthetic rate 22 , plant growth 23 and biomass production 24 (Fig.…”

Agricultural land use decouples soil nutrient cycles in a subtropical riparian wetland in China

“…Recent stoichiometric ecological studies have shown that K is even more associated than is N or P with stoichiometric differences among various plant ecotypes (Sardans and Peñuelas, 2014;Sardans et al, 2012c) or with stoichiometric shifts in response to environmental changes (Rivas-Ubach et al, 2012). The strong link between plant K concentrations and water availability (Sardans et al, 2012c;Yavitt et al, 2004) justifies the study of K and its stoichiometric relationships with other nutrients.…”

Close and distant: Contrasting the metabolism of two closely related subspecies of Scots pine under the effects of folivory and summer drought

“…Fourth, independently of the FL, the concentrations of sugars, phenolics, and amino acids such as proline (Figure 4c,d) in summer were higher in iberica than nevadensis needles, also suggesting that iberica experienced more stress in summer. In previous ecometabolomic studies, we have also observed increases in sugar, amino acid, and phenolic concentrations in different plant species during the dry summers of the Mediterranean climate (Rivas‐Ubach et al., 2012, 2014; Rivas‐Ubach, Barbeta, et al., 2016). Proline is an important osmoprotectant in plants (Szabados & Savouré, 2010), so the higher proline concentrations in the needles of iberica compared to nevadensis also suggest that this subspecies may be facing more intense drought conditions in Sierra Nevada than those in its native range in Navacerrada (Figure 3).…”

“…The metabolome is the chemical phenotype of an organism (Fiehn, 2002) and is the first to respond to biotic and abiotic stressors (Peñuelas & Sardans, 2009). The recent application of new metabolomic techniques in the fields of plant physiology and ecology (ecometabolomics) has allowed the detection of the extreme plasticity of metabolomes under different environmental situations (Rivas‐Ubach, Sardans, Pérez‐Trujillo, Estiarte, & Peñuelas, 2012; Rivas‐Ubach, Barbeta, et al., 2016; Sardans, Peñuelas, & Rivas‐Ubach, 2011). However, the metabolome, as any other aspect of the phenotype, can also be subject to evolutionary divergence given that metabolic responses ultimately depend on genetic composition and expression (Riedl et al., 2012).…”