Figure 1.
Classification of soybean metabolites into chemical groups in response to Rhizoctonia infection.
The total number of signatory metabolites at 24 h and 48 h post-inoculation (A), and the total number of signatory metabolites classified into increased and decreased in infected seedlings compared to controls at 24 h and 48 h post-inoculation (B), are displayed. For the chemical classification of metabolites information was retrieved from the database PubChem.
Figure 2.
Classification of metabolites signatory of the soybean's response to Rhizoctonia solani invasion based on their participation in plant metabolic pathways/functions, measured as instances, since a metabolite can be involved in more than one pathway.
For standardization purposes the KEGG coding system for soybean pathways is adapted. The total number of instances at 24 h and 48 h post-inoculation (A), and the total number of instances classified into increased and decreased in infected seedlings at 24 h and 48 h post-inoculation (B), are displayed.
Table 1.
Classification of signatory metabolites of soybean response to Rhizoctonia solani invasion at 24 h and 48 h post-inoculation based on their participation in biosynthetic pathways, measured as instances, since a metabolite can be involved in more than one pathway.
Figure 3.
Global soybean metabolome and its perturbation in response to Rhizoctonia solani at 48h post-inoculation (A) and sub-network generated by connecting possible paths between the displayed signatory metabolites (B) using the software Cytoscape and the cellular overview tool of SoyCyc (C).
Representative metabolites are indicated in red color (A) and (B), whereas in the panel (C), using the Data Set S2, metabolites with KEGG identifiers are highlighted.
Figure 4.
Color-coded fluctuation of the soybean's seedling metabolic network caused by Rhizoctonia solani infection at 24 h and 48 h post-inoculation, including portions of the amino acid biosynthesis, and the isoflavonoid and phenylpropanoid biosynthetic pathways, which were detected as important components of its defense mechanism.
Genes in the reference pathway of KEGG for soybean that are hyperlinked to gene entries are displayed. Metabolite fluctuations are coded using a color code based on P-values (P<0.05) performing the Student's t-test and means of scaled and centered PLS regression coefficients (CoeffCS) from five biological replications and a quality control sample per treatment. Dashed lines symbolize multi-step or not fully elucidated reactions and solid lines one-step reactions. [3PGA; 3-phosphoglycerate, isoflavone synthase 1; C3′H; coumaroylquinate (coumaroylshikimate) 3′-monooxygenase, EC: 1.14.13.36, NCBI-GeneID: 100811080, C4H; coumarate 4-hydroxylase, EC: 1.14.13.11, NCBI-GeneID: 100499623, CAD; cinnamyl-alcohol dehydrogenase, EC: 1.1.1.195, NCBI-GeneID: 100777558, CHI; chalconeisomerase (5 isozymes), F6P; fructose-6-phosphate, G6P; glucose-6-phosphate, β-Glu; glucosidase β-glucosidase, EC: 3.2.1.21, NCBI-GeneID: 100779642, HIDH; 2-hydroxyisoflavanone dehydratase, EC: 4.2.1.105, NCBI-GeneID: 547489, IF7GT; isoflavone 7′-O-glucosyltransferase, EC: 2.4.1.170, NCBI-GeneID: 100101902, IFS1; isoflavone synthase 1, EC: 5.4.99.-, NCBI-GeneID: 100037450, IOMT; isoflavone 7′-O-Methyltransferase (14 isozymes), PAL; phenylalanine ammonia-lyase, EC: 4.3.1.24, NCBI-Gene ID: 100787902, PEP; phosphoenolpyruvate].
Figure 5.
Fluctuations in the α-linolenate metabolism of soybean in response to Rhizoctonia solani at 24 h and 48 h post-inoculation coded using a color code based on P-values (P<0.05) performing the Student's t-test or means of scaled and centered PLS regression coefficients (CoeffCS) from five biological replications and a quality control sample per treatment.
Genes in the reference pathway of KEGG for soybean that are hyperlinked to gene entries are displayed. Dashed lines symbolize multi-step or not fully elucidated reactions and solid lines one-step reactions [13-HPOT; (9Z,11E,15Z)-(13S)-hydroperoxyoctadeca-9,11,15-trienoate, AOC; allene oxide cyclase, EC: 5.3.99.6, NCBI-GeneID:100800036, AOS; hydroperoxidedehydratase, EC: 4.2.1.92, NCBI-GeneID: 100037481, HPL; hydroperoxidelyase, EC: 4.1.2.-, NCBI-GeneID: 100784395, LOX; lipoxygenase, EC: 1.13.11.12, NCBI-GeneID: 100785480].
Figure 6.
Proposed graphical model for the role of Rhizoctonia solani in activation of soybean defense mechanisms.
[CM; cell membrane, CW; cell wall, G; Golgi body, M; mitochondrion, N; nucleus, P; plasmalemma, R; ribosomes, RER; rough endoplasmic reticulum, SER; soft endoplasmic reticulum, T; transporters, V; vacuole].