Proteomic characterization of copper stress response in Elsholtzia splendens roots and leaves. Plant Mol Biol
ABSTRACT Elsholtzia splendens is generally considered as a Cu-tolerant and -accumulating plant species, and a candidate for phytoremediation of Cu-contaminated soils. To better understand the Cu tolerance/accumulation mechanisms in E. splendens, proteomic analysis was performed on E. splendens roots and leaves exposed to 100 muM CuSO(4) for 3 and 6 days. After 6 days of treatment, Cu accumulation in roots increased much more than that in leaves. SDS-PAGE analysis showed that the proteins changed more intensively in roots than did in leaves upon Cu stress. Two-dimensional gel electrophoresis (2-DE) and image analyses found that 45 protein spots were significantly changed in roots, but only six protein spots in leaves. The abundance of protein spots mostly showed temporal changes. MALDI-TOF MS and LTQ-ESI-MS/MS were used to identify the differently expressed protein spots. The identified root proteins were involved in various cellular processes such as signal transduction, regulation of transcription and translation, energy metabolism, regulation of redox homeostasis and cell defense. The leaf proteins were mainly degraded fragments of RuBisCo and antioxidative protein. The roles of these proteins in Cu tolerance/accumulation were discussed. The resulting differences in protein expression pattern suggested that redirection of root cellular metabolism and redox homeostasis might be important survival mechanisms of E. splendens upon Cu stress.
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- "These processes may work cooperatively to re-establish the cellular and redox homeostasis upon Cu stress  . Most of these temporal studies, however, were carried out using short-term, high Cu exposures (e.g. 100 M Cu, 3–6 days ; 601 M Cu, 6 weeks  "
ABSTRACT: Differential expression of soluble proteins was explored in roots of metallicolous (M) and non-metallicolous (NM) plants of Agrostis capillaris L. exposed to increasing Cu to partially identify molecular mechanisms underlying higher Cu tolerance in M plants.Plants were cultivated 2 months on perlite with a CuSO4 (1–30 μM) spiked-nutrient solution. Soluble proteins extracted by the TCA/acetone procedure were separated with 2-DE (linear 4–7 pH gradient). After CCB staining and image analysis, 19 proteins differentially expressed were identified using LC-MS/MS and ESTs databases.At supra-optimal Cu exposure (15–30 μM), glycolysis was likely altered in NM roots with increased production of glycerone-P and methylglyoxal based on over-expression of Triosephosphate Isomerase and Fructose bisphosphate aldolase. Changes in Tubulins and higher expressions of 5-methyltetrahydropteroyltriglutamatehomocysteine methyltransferase and S-Adenosylmethionine synthase respectively underpinned impacts on the cytoskeleton and stimulation of ethylene metabolism. Increased L-methionine and S-Adenosylmethionine amounts may also facilitate production of nicotianamine, which complexes Cu, and L-cysteine, needed for metallothioneins and GSH. In M roots, the increase of [Cu/Zn] Superoxide dismutase suggested a better detoxification of superoxide, when Cu exposure rose. Higher Cu-tolerance of metallicolous plants would rather results from simultaneous cooperation of various processes than from a specific mechanism.This article is protected by copyright. All rights reservedProteomics 08/2014; 14(15). DOI:10.1002/pmic.201300168 · 3.81 Impact Factor
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- "Cd and Pb induced expression of the Rubisco large subunit ( Bah et al . , 2010 ) . In contrast , Cd decreased the content of both large and small subunits of Rubisco in Chlamydomonas reinhardtii ( Gillet et al . , 2006 ) . In the case of Elsholtzia splendens , a Cu - tolerant and - accumulating plant species , Rubisco was degraded and fragmented ( Li et al . , 2009 ) ."
ABSTRACT: Lichens are an excellent model to study the bioaccumulation of heavy metals but limited information is available on the molecular mechanisms occurring during bioaccumulation. We investigated the changes of the lichen proteome during exposure to constant concentrations of mercury. We found that most of changes involves proteins of the photosynthetic pathway, such as the chloroplastic photosystem I reaction center subunit II, the oxygen-evolving protein and the chloroplastic ATP synthase β-subunit. This suggests that photosynthesis is a target of the toxic effects of mercury. These findings are also supported by changes in the content of photosynthetic pigments (chlorophyll a and b, and β-carotene). Alterations to the photosynthetic machinery also reflect on the structure of thylakoid membranes of algal cells. Response of lichens to mercury also involves stress-related proteins (such as Hsp70) but not cytoskeletal proteins. Results suggest that lichens adapt to mercury exposure by changing the metabolic production of energy.Environmental Pollution 01/2012; 160(1):1-10. DOI:10.1016/j.envpol.2011.09.015 · 4.14 Impact Factor
Conference Paper: Iterative multiuser detection for space-time coded synchronous CDMA[Show abstract] [Hide abstract]
ABSTRACT: Multiuser detectors for trellis space-time coded synchronous CDMA, operating in the presence of independent Rayleigh fading are considered. The joint optimal maximum likelihood (ML) multiuser detector, which can be implemented as a Viterbi algorithm, is derived for such space-time coded systems. A suboptimal, low complexity iterative space-time multiuser detector based on interference cancellation and the turbo principle is also derived. Simulations show that this latter method achieves performance competitive with the single user bound for space-time coded systemsVehicular Technology Conference, 2001. VTC 2001 Fall. IEEE VTS 54th; 02/2001