Next Article in Journal / Special Issue
Metabolomics for Biomarker Discovery in Gastroenterological Cancer
Previous Article in Journal
NblA1/A2-Dependent Homeostasis of Amino Acid Pools during Nitrogen Starvation in Synechocystis sp. PCC 6803
Previous Article in Special Issue
Molar-Based Targeted Metabolic Profiling of Cyanobacterial Strains with Potential for Biological Production
Metabolites 2014, 4(3), 532-546; doi:10.3390/metabo4030532
Article

Insect-Induced Daidzein, Formononetin and Their Conjugates in Soybean Leaves

1
, 1
, 1
, 1
, 1
, 1
, 3
, 1
, 2
, 2
 and 1,*
1 Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan 2 Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, USDA, 1600 S.W. 23RD Drive, Gainesville, FL 32606, USA 3 Department of Agriculture, Tottori University, Koyama-machi 4-101, Tottori 680-8550, Japan
* Author to whom correspondence should be addressed.
Received: 29 April 2014 / Revised: 23 June 2014 / Accepted: 24 June 2014 / Published: 4 July 2014
(This article belongs to the Special Issue Metabolomics and Biotechnology)
View Full-Text   |   Download PDF [752 KB, uploaded 4 July 2014]   |   Browse Figures

Abstract

In response to attack by bacterial pathogens, soybean (Gylcine max) leaves accumulate isoflavone aglucones, isoflavone glucosides, and glyceollins. In contrast to pathogens, the dynamics of related insect-inducible metabolites in soybean leaves remain poorly understood. In this study, we analyzed the biochemical responses of soybean leaves to Spodoptera litura (Lepidoptera: Noctuidae) herbivory and also S. litura gut contents, which contain oral secretion elicitors. Following S. litura herbivory, soybean leaves displayed an induced accumulation of the flavone and isoflavone aglycones 4’,7-dihyroxyflavone, daidzein, and formononetin, and also the isoflavone glucoside daidzin. Interestingly, foliar application of S. litura oral secretions also elicited the accumulation of isoflavone aglycones (daidzein and formononetin), isoflavone 7-O-glucosides (daidzin, ononin), and isoflavone 7-O-(6’-O-malonyl-β-glucosides) (malonyldaidzin, malonylononin). Consistent with the up-regulation of the isoflavonoid biosynthetic pathway, folair phenylalanine levels also increased following oral secretion treatment. To establish that these metabolitic changes were the result of de novo biosynthesis, we demonstrated that labeled (13C9) phenylalanine was incorporated into the isoflavone aglucones. These results are consistent with the presence of soybean defense elicitors in S. litura oral secretions. We demonstrate that isoflavone aglycones and isoflavone conjugates are induced in soybean leaves, not only by pathogens as previously demonstrated, but also by foliar insect herbivory.
Keywords: plant-insect interaction; plant induced resistance; insect-produced elicitors; isoflavones; insect herbivory; secondary metabolites; liquid chromatography; mass spectrometry plant-insect interaction; plant induced resistance; insect-produced elicitors; isoflavones; insect herbivory; secondary metabolites; liquid chromatography; mass spectrometry
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Share & Cite This Article

Export to BibTeX |
EndNote


MDPI and ACS Style

Murakami, S.; Nakata, R.; Aboshi, T.; Yoshinaga, N.; Teraishi, M.; Okumoto, Y.; Ishihara, A.; Morisaka, H.; Huffaker, A.; Schmelz, E.A.; Mori, N. Insect-Induced Daidzein, Formononetin and Their Conjugates in Soybean Leaves. Metabolites 2014, 4, 532-546.

View more citation formats

Supplement

Related Articles

Article Metrics

Comments

Citing Articles

[Return to top]
Metabolites EISSN 2218-1989 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert