Silicon ameliorates manganese toxicity by regulating physiological processes and expression of genes associated with photosynthesis in rice (Oryza sativa L.)

Li, Ping and Song, Alin and Li, Zhaojun and Fan, Fenliang and Liang, Yongchao (2015) Silicon ameliorates manganese toxicity by regulating physiological processes and expression of genes associated with photosynthesis in rice (Oryza sativa L.). Plant and Soil, 397 (1-Feb). pp. 289-301. ISSN 0032-079X

Abstract

Background and aims: We investigated the effects of silicon (Si) on chlorophyll concentration, photosynthesis, leaf chloroplast ultrastructure, and expression of genes involved in photosynthesis to elucidate the mechanisms through which Si mediated alleviation of manganese (Mn) toxicity in rice (Oryza sativa L.).

Methods: Rice seedlings were grown hydroponically with normal Mn (6.7 μM) or high Mn (2 mM) concentrations, both with (1.5 mM) and without Si supplementation. Leaf chloroplast ultrastructure was observed by scanning and transmission electron microscopy. Differentially expressed genes relating to photosynthesis were identified by highthroughput sequencing, and their relative expression levels were evaluated by real-time quantitative PCR.

Results: Chlorophyll and carotenoid concentrations and net photosynthesis decreased with chloroplast degradation under high Mn stress. High Mn concentrations may have inhibited photosynthesis through several mechanisms, including suppressing chlorophyll and ATP synthesis, decreasing light-harvesting processes, impairing photosystem I (PSI) stability and structure, and slowing activity of phosphoribulokinase. Si enhanced Mn tolerance efficiently by increasing chlorophyll concentration, light-use efficiency,and ATP concentration aswell as by stabilizing the structure of PSI and promoting CO2 assimilation.

Conclusions Our findings suggest active involvement of Si in Mn detoxification, ranging from physiological responses to gene expression.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: No Faculty
Date Deposited: 02 Jun 2016 06:07
Last Modified: 02 Aug 2016 04:54
Uncontrolled Keywords: gene expression; Mn toxicity; photosynthesis; rice; silicon
Fields of Research : 05 Environmental Sciences > 0503 Soil Sciences > 050305 Soil Physics
Socio-Economic Objective: D Environment > 96 Environment > 9614 Soils > 961402 Farmland, Arable Cropland and Permanent Cropland Soils
Identification Number or DOI: 10.1007/s11104-015-2626-y
URI: http://eprints.usq.edu.au/id/eprint/28897

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