Biochemical changes in barley plants after excessive supply of copper and manganese

Demirevska-Kepova, K.; Simova Stoilova, Lyudmila; Stoyanova, Z.; Hölzer, Regina; Feller, Urs (2004). Biochemical changes in barley plants after excessive supply of copper and manganese. Environmental and Experimental Botany, 52(3), pp. 253-266. Elsevier Science 10.1016/j.envexpbot.2004.02.004

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The present study was undertaken to identify changes in some important proteins involved in CO2 fixation (Rubisco, Rubisco activase (RA), Rubisco binding protein (RBP)), NH4+ assimilation (glutamine synthetase (GS) and glutamate synthase (GOGAT)), using immunoblotting, and in the antioxidative defense as a result of Cu or Mn excess in barley leaves (Hordeum vulgare L. cv. Obzor). Activities and isoenzyme patterns of superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and catalase (CAT), as well as the levels of ascorbate (ASC), non-protein sulfhydryl groups, hydrogen peroxide and oxidative damage to proteins were determined. Data were correlated to the accumulation of Cu or Mn in the leaves after 5 days supply of heavy metal (HM) excess in the nutrient solution. In the highest Cu excess (1500 μM), Rubisco LS and SS were reduced considerably whereas under the highest Mn concentrations (18,300 μM) only minor changes in Rubisco subunits were detected. The RBP was diminished under the highest concentrations of both Cu or Mn. The bands of RA changed differently comparing Cu and Mn toxicity. GS decreased and GOGAT was absent under the highest concentration of Cu. At Mn excess Fd-GOGAT diminished whereas GS was not apparently changed. The development of toxicity symptoms corresponded to an accumulation of Cu or Mn in the leaves and to a gradual increase in protein carbonylation, a lower SOD activity and elevated CAT and GPX activities. APX activity was diminished under Mn toxicity and was not changed under Cu excess. Generally, changes in the isoenzyme profiles were similar under both toxicities. An accumulation of H2O2 was observed only at Mn excess. Contrasting changes in the low-molecular antioxidants were detected when comparing both toxicities. Cu excess affected mainly the non-protein SH groups, while Mn influenced the ASC content. Oxidative stress under Cu or Mn toxicity was most probably the consequence of depletion in low-molecular antioxidants as a result of their involvement in detoxification processes and disbalance in antioxidative enzymes. The link between heavy metal accumulation in leaves, leading to different display of oxidative stress, and changes in individual chloroplast proteins is discussed in the article.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Plant nutrition [discontinued]
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

Simova Stoilova, Lyudmila; Hölzer, Regina and Feller, Urs

Subjects:

500 Science > 580 Plants (Botany)

ISSN:

0098-8472

Publisher:

Elsevier Science

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

17 Dec 2015 14:53

Last Modified:

17 Dec 2015 14:53

Publisher DOI:

10.1016/j.envexpbot.2004.02.004

Uncontrolled Keywords:

Rubisco, Rubisco binding protein, Rubisco activase, Glutamine synthetase, Glutamate synthase, Copper, Manganese, Toxicity, Oxidative stress, Barley (Hordeum vulgare L.)

BORIS DOI:

10.7892/boris.74009

URI:

https://boris.unibe.ch/id/eprint/74009

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