Metabolite Changes in Soybean (Glycine max) Leaves during the Entire Growth Period

Abstract

Although soybean (Glycine max) leaves generate building blocks to produce seeds, a comprehensive understanding of the metabolic changes in soybean leaves during the entire growth stages is limited. Here, we investigated the metabolite changes in soybean leaves from five cultivars among four vegetative (V) and eight reproductive (R) stages using metabolite profiling coupled with chemometrics. Principal component analysis (PCA) of all samples showed a clear separation by growth stage. The total amount of monosaccharides and organic acids for energy production were highly detected in the V stage samples, accumulating in concentrations 2.5 and 1.7 times higher than in the R stage samples, respectively. The results of partial least-squares-discriminant analysis (PLS-DA) revealed a clear separation from R1 to R5 by the first PLS, suggesting significant alterations in the metabolic networks up to R5. After flowering, the stage of seed formation, R5, was associated with lower levels of most amino acids and an accumulation of phytosterols. The negative correlation observed between amino acids and phytosterol levels suggests a sophisticated coordination between carbon and nitrogen metabolism in plant, ensuring and supporting optimal growth (r = −0.50085, P = 0.0001). In addition, R-stage samples had decreased monosaccharide levels, indicating redistribution to seeds and senescence-related metabolite changes. Thus, metabolite profiling coupled with chemometrics could be a useful tool for investigating alterations in metabolic networks during various plant growth and development stages. Furthermore, we observed variations in flavonoid contents among the different cultivars. The results could be a basis of further studies on the source−sink interactions in the plant system.

Effect of Different Sowing Seasons, Growth Stages, Leaf Positions, and Soybean Varieties on the Growth of Clanis bilineata tsingtauica Mell Larvae

“…The difference in larval weight at different growth stages of soybeans may also be related to the nutrient content of the leaves. The cumulative concentrations of monosaccharides and organic acids, used for energy production, in the vegetative stage of soybeans were 2.5 and 1.7 times greater than those found in samples from the reproductive stage, respectively [52].…”

“…In autumn sowing, the difference in the weight of the larvae fed at different leaf positions in the V6 stage was more significant than in the R3 stage. This might be related to the lower nutrient content of leaves in the R3 stage [52].…”