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Alleviation of Copper Toxicity in Arabidopsis thaliana by Silicon Addition to Hydroponic Solutions

Permanent URL:
http://handle.nal.usda.gov/10113/22525
Abstract:
Copper (Cu) is an essential micronutrient for plants and is the a.i. in pesticides for some pathogens and algae. Elevated doses of Cu can cause toxicity in plants. While silicon (Si) is reported to alleviate the toxicity of some heavy metals, its role in reducing the symptoms induced by excess Cu is unclear. Therefore, the role of Si in plant response to Cu stress was investigated in arabidopsis [Arabidopsis thaliana (L.) Heyn.]. Based on plant symptoms (a reduction of leaf chlorosis as well as increased shoot and root biomass) and a reduction of phenylalanine ammonia lyase [PAL (EC 4.3.1.5), a stress-induced enzyme] activity in the shoot, Si was found to alleviate copper stress. Real-time reverse transcriptase-polymerase chain reaction analyses indicated that the RNA levels of two arabidopsis copper transporter genes, copper transporter 1 (COPT1) and heavy metal ATPase subunit 5 (HMA5) were induced by high levels of Cu, but were significantly decreased when Si levels were also elevated. Taken together, our findings indicate that Si addition can improve the resistance of arabidopsis to Cu stress, and this improvement operates on multiple levels, ranging from physiological changes to alterations of gene expression.
Author(s):
Li, Jie , Leisner, Scott M. , Frantz, Jonathan
Subject(s):
Arabidopsis thaliana , copper , phytotoxicity , silicon , nutrient excess , plant nutrition , hydroponics , nutrient-nutrient interactions , signs and symptoms (plants) , chlorosis , dry matter accumulation , shoots , roots , phenylalanine ammonia-lyase , reverse transcriptase polymerase chain reaction , messenger RNA , transport proteins , protein synthesis , gene expression regulation , mechanism of action
Format:
p. 670-677.
Note:
Includes references
Source:
Journal of the American Society for Horticultural Science 2008 Sept, v. 133, no. 5
Language:
English
Year:
2008
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
File:
Download [PDF File]
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.