Abstract
To assess the influence of bacteria inoculation on carbon flow through maize plant and rhizosphere,14C allocation after14CO2 application to shoots over a 5-day period was determined. Plants were grown on C- and N-free quartz sand in two-compartment pots, separating root and shoot space. While one treatment remained uninoculated, treatments two and three were inoculated withPantoea agglomerans (D5/23) andPseudomonas fluorescens (Ps I A12), respectively, five days after planting. Bacterial inoculation had profound impacts on carbon distribution within the system. Root/rhizosphere respiration was increased and more carbon was allocated to roots of plants being inoculated. After five days of14CO2 application, more ethanol-soluble substances were found in roots of inoculated treatments and lower rhizodeposition indicated intensive C turnover in the rhizosphere. In both inoculated treatments the intensity of photosynthesis measured as net-CO2-assimilation rates were increased when compared to the uninoculated plants. However, high C turnover in the rhizosphere reduced shoot growth of D5/23 inoculated plants, with no effect on shoot growth of Ps I A12 inoculated plants. A separation of labeled compounds in roots and rhizodeposition revealed that neutral substances (sugars) constituted the largest fraction. The relative fractions of sugars, amino acids and organic acids in roots and rhizodeposition suggest that amino acid exudation was particularly stimulated by bacterial inoculation and that turnover of this substance group is high in the rhizosphere.
Similar content being viewed by others
References
Barber D A and Gunn K B 1974 The effect of mechanical forces on the exudation of organic substances by the roots of cereal plants grown under sterile conditions. New Phytol. 73, 39–45.
Benizri E, Baudoin E and Guckert A 2001 Root colonization by inoculated plant growth-promoting rhizobacteria. Biocontrol Sci. Technol. 11, 557–574.
Bent E, Tuzun S, Chanway C P and Enebak S 2001 Alterations in plant growth and in root hormone levels of lodgepole pines inoculated with rhizobacteria. Can. J. Microbiol. 47, 793–800.
Boddey R M and Döbereiner J 1988 Nitrogen fixation associated with grasses and cereals: Recent results and perspectives for future research. Plant and Soil 108, 53–65.
Deubel A, Gransee A and Merbach W 2000 Transformation of organic rhizodeposition by rhizosphere bacteria and its influence on the availability of tertiary calcium phosphate. J. Plant Nutr. Soil Sci. 163, 387–392.
Dobbelaere S, Croonenborghs A, Thys A, Ptacek D, Vanderleyden J, Dutto P, Labandera-Gonzalez C, Caballero-Mellado J, Aguirre J F, Kapulnik Y, Brener S, Burdman S, Kadouri D, Sarig S and Okon Y 2001 Responses of agronomically important crops to inoculation withAzospirillum. Australian J. Plant Physiol. 28, 871–879.
Gransee A and Wittenmayer L 2000 Quantitative and qualitative analysis of water-soluble root exudates in relation to growth factors. J. Plant Nutr. Soil Sci. 163, 381–385.
Hirte W F 1961 Glycin-Pepton-Agar, ein vorteilhafter Nährboden für bodenbakteriologisches Arbeiten. Zentralblatt Bakteriol., Abt. II 114, 141–146.
Hoagland D R and Snyder, W C 1933 Nutrition of strawberry plants under controlled conditions: (a) Effects of deficiencies of boron and certain other elements; (b) susceptibility to injury from sodium solts. Proc. Amer. Soc. Hortic. Sci. 30, 288–294.
H°flich G 1992 Wechselwirkungen zwischen phytoeffektiven Pseudomonas-Bakterien und dem Wachstum von Kulturpflanzen. Zentralbl. Mikrobiol. 147, 182–191.
H°flich G and Ruppel S 1994 Growth stimulation of pea after inoculation with associative bacteria. Microbiological Res. 149, 99–104.
Janzen H H 1990 Deposition of nitrogen into the rhizosphere by wheat roots. Soil Biol. Biochem. 22, 1155–1160.
Kraffczyk I, Trolldenier G and Beringer H 1984 Soluble root exudates of maize: influence of potassium supply and rhizosphere microorganisms. Soil Biol. Biochem. 16, 315–322.
Kumar B S D, Berggren I and Martensson A M 2001 Potential for improving pea production by co-inoculation with fluorescentPseudomonas andRhizobium. Plant and Soil 229, 25–34.
Lynch J M and Whipps J M 1990 Substrate flow in the rhizosphere. Plant and Soil 129, 1–10.
Merbach W, Mirus E, Knof G, Remus R, Ruppel S, Russow R, Gransee A and Schulze J 1999 Release of carbon and nitrogen compounds by plant roots and their possible ecological importance. J. Plant Nutr. Soil Sci. 162, 373–383.
Merbach W, Ruppel S and Schulze J 1998 Dinitrogen fixation of microbe-plant associations as affected by nitrate and ammonium supply. Isotopes in Environ. and Health Stud. 34, 67–73.
Okon Y and Itzigsohn R 1995 The development ofAzospirillum as a commercial inoculant for improving crop yields. Biotechnol. Adv. 13, 415–424.
Reining E, Merbach W and Knof G 199515N distribution in wheat and chemical fractionation of root-borne15N in the soil. Isotopes in Environ. and Health Stud. 31, 345–349.
Reyes I, Bernier L and Antoun H 2002 Rock phosphate solubilization and colonization of maize rhizosphere by wild and genetically modified strains ofPenicillium rugulosum. Microbial Ecology 44, 39–48.
Rovira A D 1969 Plant root exudates. Botanical Review 35, 35–57.
Ruppel S and Wache H 1990 Isolation und Selektion phytoeffektiver Bakterien. Zentralbl. Mikrobiol. 145, 599–603.
Schilling G, Gransee A, Deubel A, Lezovic G and Ruppel S 1998 Phosphorus availability, root exudates, and microbial activity in the rhizosphere. J. Plant Nutr. Soil Sci. 161, 465–478.
Scholz-Seidel C and Ruppel S 1992 Nitrogenase- and phytohormone activities ofPantoea agglomerans in culture and their reflections in combination with wheat plants. Zentralblatt Bakteriol., Abt. II 147, 319–328.
Schulze J, Adgo E and Merbach W 1999 Carbon costs associated with N2 fixation inVicia faba L. andPisum sativum L. over a 14-day period. Plant Biol. 1, 625–631.
Singh S and Kapoor K K 1999 Inoculation with phosphate-solubilizing microorganisms and a vesicular arbuscular mycorrhizal fungus improves dry matter yield and nutrient uptake by wheat grown in a sandy soil. Biol. Fert. Soils 28, 139–144.
Stumpf D R and Burris R N 1979 A micromethod for the purification and quantification of organic acids of the tricarboxylic acid cycle in plant tissues. Analytical Biochem. 95, 311–315.
Van Nieuwenhove C, Van Holm L, Kulasooriya S A and Vlassak K 2000 Establishment ofAzorhizobium caulinodans in the rhizosphere of wetland rice (Oryza sativa L.). Biol. Fert. Soils 31, 143–149.
Westover K M and Bever J D 2001 Mechanisms of plant species coexistence: Roles of rhizosphere bacteria and root fungal pathogens. Ecology 82, 3285–3294.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Schulze, J., Pöschel, G. Bacterial inoculation of maize affects carbon allocation to roots and carbon turnover in the rhizosphere. Plant Soil 267, 235–241 (2004). https://doi.org/10.1007/s11104-005-4980-7
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11104-005-4980-7