Metabolite profiling of soybean root exudates under phosphorus deficiency

Abstract

Root exudates are derived from plant metabolites and their composition is affected by the plant nutritional status. The purpose of this study was to examine soybean root exudates under phosphorus (P) deficiency using a metabolite profiling technique. Glycine max L. (cv. Suzuyutaka) was grown in a culture solution at P concentrations of 0 (P0) and 8 (P8) mg P L −1 for 1, 5, 10 and 15 days after transplanting. Shoot extract, root extract and root exudates were collected and their metabolites were determined by capillary electrophoresis/ time-of-flight mass spectrometry (CE-TOF MS). The shoot P concentration and dry weight of soybean plants grown at P0 were lower than those at P8. One hundred and eight, 116 and 79 metabolites were identified in the shoot extract, root extract and root exudates, respectively. The concentrations of several metabolites including amino acids and organic acids in root exudates were higher at P0 than at P8, irrespective of the P concentration in the shoot or root extract. These findings suggest that soybean roots actively release metabolites in response to P deficiency.

Developmental and nutritional regulation of isoflavone secretion from soybean roots

“…Nitrogen deficiency did not induce the expression of ICHG in root, suggesting that an ATP-dependent transporter contributes the secretion of isoflavones during the nitrogen deficiency in addition to the ICHG-mediated secretion. In soybeans, the root exudation of amino acids and organic acids was induced by phosphate deficiency, 17) whereas isoflavone secretion was somewhat reduced and the tissue isoflavone contents were not significantly altered.…”

“…13,14) Plant growth stages as well as the nutrient deficiency such as nitrogen, phosphate, and iron have been found to significantly affect the secretion of metabolites into the rhizosphere. [15][16][17][18] In rice, for example, the amount of root exudates was the lowest at seedling stage, gradually increased until flowering, and decreased at maturity. 19) In Arabidopsis, metabolites secreted from roots were dynamically altered during development, in correlation with the transcriptomes of rhizosphere microbial communities.…”

Plant species-dependent transformation and translocation of ceria nanoparticles

“…Secondly, root exudates play a critical role in the transformation of nCeO 2 in plants. We extracted the root exudates from the plants according to a previously described method, 27 and found that the hydrodynamic sizes of nCeO 2 in root exudate solutions varied among the four plant species (Fig. S8 and S9 †).…”

“…Root exudates are composed of low molecular compounds such as saccharides, organic acids, amino acids, phenols, high molecular polysaccharides and proteins. 27 The low molecular organic acids (e.g., succinic acid and malic acid) 8 and reducing substances such as phenols, 28 which are critical for the transformation of nCeO 2 , varied among different species. Moreover, different acids and reducing substances have different capacities to dissolve the nCeO 2 .…”

The carboxylate composition of rhizosheath and root exudates from twelve species of grassland and crop legumes with special reference to the occurrence of citramalate

“…It is also found in relation to anthocyanin accumulation in the skin of red apples (Fernández-Trujillo et al 2001;Noro et al 1988). However, it has rarely been studied in the context of root exudation (Khorassani et al 2011;Tawaraya et al 2014). It has been found to solubilise sparingly available P through ligand exchange, but was reported to be less effective than citrate (Khorassani et al 2011).…”