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Titolo:
EFFECTS OF EXCESS MANGANESE ON PRODUCTION OF ORGANIC-ACIDS IN MN-TOLERANT AND MN-SENSITIVE CULTIVARS OF TRITICUM-AESTIVUM L (WHEAT)
Autore:
MACFIE SM; COSSINS EA; TAYLOR GJ;
Indirizzi:
TRENT UNIV,ENVIRONM & RESOURCE STUDIES PROGRAM PETERBOROUGH K9J 7B8 ON CANADA UNIV ALBERTA,DEPT BOT EDMONTON T6G 2E9 AB CANADA
Titolo Testata:
Journal of plant physiology
fascicolo: 2, volume: 143, anno: 1994,
pagine: 135 - 144
SICI:
0176-1617(1994)143:2<135:EOEMOP>2.0.ZU;2-R
Fonte:
ISI
Lingua:
ENG
Soggetto:
DESCHAMPSIA-CAESPITOSA; SOLUTION CULTURE; ZINC TOLERANCE; ALUMINUM; TOXICITY; PLANTS;
Keywords:
ACONITATE; ALPHA-KETOGLUTARATE; CITRATE; MALATE; MANGANESE; ORGANIC ACIDS; PHOTOSYNTHESIS; RESPIRATION; SPECIFIC RADIOACTIVITY; SUCCINATE; TOLERANCE; TOXICITY; TRITICUM AESTIVUM L;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
24
Recensione:
Indirizzi per estratti:
Citazione:
S.M. Macfie et al., "EFFECTS OF EXCESS MANGANESE ON PRODUCTION OF ORGANIC-ACIDS IN MN-TOLERANT AND MN-SENSITIVE CULTIVARS OF TRITICUM-AESTIVUM L (WHEAT)", Journal of plant physiology, 143(2), 1994, pp. 135-144

Abstract

Tolerance to metals may be achieved via enhanced production of organic acids and subsequent formation of stable metal-organic acid complexes in the cytosol or vacuole. To determine the relationship between differential tolerance to Mn and organic acid content in Triticum aestivum L., a Mn-tolerant and a Mn-sensitive cultivar were grown in solutionculture with 0, 250 or 500 mu M Mn. Exposure to excess Mn reduced rates of growth and photosynthesis in the Mn-sensitive cultivar, while respiration declined after an initial stimulation. In the Mn-tolerant cultivar, growth was not affected by excess Mn, and toxic effects on photosynthesis and respiration were less pronounced. Under these conditions, six carboxylate anions were detected in root and leaf tissues, five of which were present in sufficient amounts for quantification. In roots, concentrations of aconitate, alpha-ketoglutarate, citrate, malate, and succinate did not differ between Mn-tolerant and Mn-sensitive cultivars. In leaves, growth in excess Mn was accompanied by increases in the concentrations of aconitate, alpha-ketoglutarate, and succinatein the Mn-sensitive cultivar only. To examine the effects of Mn or organic acid synthesis, leaf slices from plants grown for 11 d in the presence or absence of Mn (500 mu M) were incubated in [2-C-14]sodium acetate. Growth in excess Mn increased concentrations of succinate in the leaf slices but decreased its specific radioactivity, indicating that its synthesis was not solely via acetyl CoA feeding into the citric-acid cycle. The specific radioactivity of malate also declined with Mnstress. Observed increases in organic acid content in the Mn-sensitive cultivar, the lack of similar increases in the Mn-tolerant cultivar,and the general decline in specific radioactivity of labeled organic acids indicates that enhanced production of organic acids is not a primary mechanism of Mn-tolerance. Such effects more likely reflect responses to Mn toxicity.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/07/20 alle ore 14:48:23