The use of metabolome analysis to identify the cause of an unexplained disease of Japanese gentians (Gentiana triflora)
- 242 Downloads
Gentian spotted bleaching disease (GSBD), a novel disease of unknown etiology, affects Gentiana triflora plants that are cultivated as ornamental flowers in Japan. This disease leads to the production of necrotic leaf spots, a delay in flowering, and has thus become a serious problem for gentian production.
The objective of this study was to identify the cause of GSBD in G. triflora by analyzing differences between healthy and GSBD-affected leaves.
Selected metabolite concentrations in healthy and GSBD-affected leaves were quantified using capillary electrophoresis and liquid chromatography-mass spectrometry, and statistically significant differences in metabolite concentrations were assessed. GSBD-affected metabolic pathways were identified followed by examination of pathway-related gene expression and enzyme activities. Furthermore, the effects of root hypoxia on metabolite concentrations and gene expression were investigated.
We found that concentrations of Calvin cycle intermediates and ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity were significantly lower in GSBD-affected leaves, whereas sucrose cleavage and Ala accumulation were enhanced. Since these metabolic changes are frequently observed in plants exposed to hypoxia, the expression of hypoxia-responsive genes was investigated. Expression levels of hypoxia-responsive genes were higher in GSBD-affected plants than in the controls. Furthermore, root hypoxia induced similar symptoms and metabolic changes as those observed in GSBD-affected plants.
Our results indicate that GSBD was likely induced by root hypoxia and that metabolome analysis is an effective tool for identifying the cause of plant disease with unknown etiologies.
KeywordsGentiana triflora Hypoxia Mass spectrometry Physiological disorder Targeted metabolome analysis
This research was supported in part by a Grant-in-Aid for Scientific Research (B) (No. 15H04454) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, and by Iwate Prefecture. The authors wish to thank Dr. Masahiro Nishihara and Mr. Zenbi Naitoh for providing helpful advice and Ms. Chiharu Yoshida, Ms. Ayumi Obara, Ms. Yuko Kanno, and Ms. Sayaka Fujisaki for technical assistance.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- Abdel-Latif, A. (2008). Activity of sucrose synthase and acid invertase in wheat seedlings during a cold-shock using micro plate reader assays. Australian Journal of Basic and Applied Sciences, 2, 53–56.Google Scholar
- Armengaud, P., Sulpice, R., Miller, A. J., Stitt, M., Amtmann, A., & Gibon, Y. (2009). Multilevel analysis of primary metabolism provides new insights into the role of potassium nutrition for glycolysis and nitrogen assimilation in Arabidopsis roots. Plant Physiology, 150, 772–785.CrossRefPubMedPubMedCentralGoogle Scholar
- Kocal, N., Sonnewald, U., & Sonnewald, S. (2008). Cell wall-bound invertase limits sucrose export and is involved in symptom development and inhibition of photosynthesis during compatible interaction between tomato and Xanthomonas campestris pv vesicatoria. Plant Physiology, 148, 1523–1536.CrossRefPubMedPubMedCentralGoogle Scholar
- Motohashi, R., & Myouga, F. (2015). Chlorophyll fluorescence measurements in Arabidopsis plants using a pulse-amplitude-modulated (PAM) fluorometer. Bio-protocol, 5, e1464. http://www.bio-protocol.org/e1464.Google Scholar
- Rocha, M., Licausi, F., Araujo, W. L., Nunes-Nesi, A., Sodek, L., Fernie, A. R., et al. (2010). Glycolysis and the tricarboxylic acid cycle are linked by alanine aminotransferase during hypoxia induced by waterlogging of Lotus japonicus. Plant Physiology, 152, 1501–1513.CrossRefPubMedPubMedCentralGoogle Scholar