Transcriptional and physiological analyses identify a regulatory role for hydrogen peroxide in the lignin biosynthesis of copper-stressed rice roots
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Induction of lignin biosynthesis is an adaptive response of plants subjected to many abiotic stresses. In this study, we examined the response of lignin biosynthesis to copper (Cu) stress, with a particular focus on the regulatory mechanism.
We performed a transcriptomic analysis of rice (Oryza sativa L.) roots, and the microarray data on lignin biosynthesis pathway genes were corroborated by quantitative reverse transcription–polymerase chain reaction (qRT-PCR) analysis. Physiological analyses of rice seedlings treated with Cu(II) sulfate (CuSO4) were used to confirm the relationship between excess Cu and lignin biosynthesis. In addition, we examined the role of hydrogen peroxide (H2O2) in Cu-induced lignin biosynthesis through pretreatments with an NADPH oxidase inhibitor (diphenyleneiodonium, DPI) and a H2O2 scavenger (dimethylthiourea, DMTU).
Lignin biosynthesis pathway genes were upregulated under Cu stress. The lignin content of rice roots increased significantly with increasing concentrations and durations of Cu treatment; elevations in root lignin content were correlated with marked inhibitions in root growth. Pretreatments with DPI and DMTU inhibited the activities of Cu-induced lignin polymerization enzymes (peroxidase, POD and laccase, LAC) and lignin accumulation in rice roots. Conversely, exogenous H2O2 increased the root lignin content.
Rice roots under Cu stress accumulate lignin through enhanced polymerization of lignin monolignol, a mechanism that requires Cu stress induced H2O2.
KeywordsCopper Oryza sativa L Lignin biosynthesis Peroxidase Laccase
This work was supported by research grants from the Project of the National Natural Science Foundation of China (No. 31172021),“the Fundamental Research Funds for the Central Universities (KYRC201302, KYTZ201402)” and the Innovative Research Team Development Plan of the Ministry of Education of China (grant no. IRT1256).
- Berthet S, Demont–Caulet N, Pollet B, Bidzinskia P, Cézarda L, Le Brisa P, Borrega N, Herve J, Blondet E, Balzergue S, Lapierre C, Jouanin L (2011) Disruption of LACCASE4 and 17 results in tissue–specific alterations to lignification of Arabidopsis thaliana stems. Plant Cell 23(3):1124–1137PubMedCentralPubMedCrossRefGoogle Scholar
- Bykov I (2008) Characterization of natural and technical lignins using FTIR spectroscopy. Dissertation, Lulea University of TechnologyGoogle Scholar
- Dai D, Fan M (2011) Investigation of the dislocation of natural fibres by Fourier-transform infrared spectroscopy. VibSpectrosc 55(2):300–306Google Scholar
- Jaleel CA, Manivannan P, Sankar B, Kishorekumar A, Gopi R, Somasundaram R, Panneerselvam R (2007) Water deficit stress mitigation by calcium chloride in Catharanthu sroseus: Effects on oxidative stress, proline metabolism and indole alkaloid accumulation. Colloids Surf B: Biointerfaces 60(1):110–116PubMedCrossRefGoogle Scholar
- Marschner H (2012) Mineral nutrition of higher plants, 3rd edn. Academic, London, p 651Google Scholar
- Navari-Izzo F, Quartacci MF (2001) Phytoremediation of metals: tolerance mechanisms against oxidative stress. Minerva Biotechnol 13:23–83Google Scholar
- Schmidt R, Mieulet D, Hubberten HM, Obata T, Hoefgen R, Fernie AR, Fisahn J, San Segundo B, Guiderdoni E, Schippers JHM, Mueller-Roeber B (2013) SALT-RESPONSIVE ERF1 regulates reactive oxygen species-dependent signaling during the initial response to salt stress in rice. Plant Cell 25(6):2115–2131PubMedCentralPubMedCrossRefGoogle Scholar
- Singleton VL, Rossi JA (1965) Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. Am J Enol Viticult 16(3):144–158Google Scholar