Effect of enhanced atmospheric CO₂ on mycorrhizal colonization by Glomus mosseae in Plantago lanceolata and Trifolium repens

Abstract

Plantago lanceolata L. and Trifolium repens L. were grown for 16 wk in ambient (360 µmol mol −" ) and elevated (610 µmol mol −" ) atmospheric CO # . Plants were inoculated with the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe and given a phosphorus supply in the form of bonemeal, which would not be immediately available to the plants. Seven sequential harvests were taken to determine whether the effect of elevated CO # on mycorrhizal colonization was independent of the effect of CO # on plant growth. Plant growth analysis showed that both species grew faster in elevated CO # and that P. lanceolata had increased carbon allocation towards the roots. Elevated CO # did not affect the percentage of root length colonized (RLC) ; although total colonized root length was greater, when plant size was taken into account this effect disappeared. This finding was also true for root length colonized by arbuscules. No CO # effect was found on hyphal density (colonization intensity) in roots. The P content of plants was increased at elevated CO # , although both shoot and root tissue P concentration were unchanged. This was again as a result of bigger plants at elevated CO # . Phosphorus inflow was unaffected by CO # concentrations. It is concluded that there is no direct permanent effect of elevated CO # on mycorrhizal functioning, as internal mycorrhizal development and the mycorrhizal P uptake mechanism are unaffected. The importance of sequential harvests in experiments is discussed. The direction for future research is highlighted, especially in relation to C storage in the soil.

Effect of enhanced atmospheric CO2 on mycorrhizal colonization and phosphorus inflow in 10 herbaceous species of contrasting growth strategies

“…Therefore, in these host plant species, there is no evidence for a direct effect of elevated CO 2 on mycorrhizal functioning as internal mycorrhizal colonization and the mycorrhizal P uptake mechanism are unaffected. Following on from our previous experiment (looking at the effects of elevated CO 2 on mycorrhizal colonization by G. mosseae in P. lanceolata and T. repens over seven harvests) (Staddon et al 1998), this experiment clearly demonstrates that internal mycorrhizal colonization (in the case of G. mosseae) is unresponsive to elevated CO 2 treatment in a wide range of species of different growth types, both dicots and monocots and legumes and non-legumes. An outstanding question, however, is whether the external mycorrhizal network responds to an elevated CO 2 environment, as a consequence of increased plant growth.…”

“…A previous seven-harvest experiment investigating Glomus mosseae colonization of Plantago lanceolata and T. repens at ambient and elevated CO 2 concentrations, showed that there was no direct effect of elevated CO 2 on mycorrhizal colonization and functioning in relation to uptake of phosphorus (Staddon et al 1998). The experiment reported in this paper was designed to test that the above conclusion was not restricted to P. lanceolata and T. repens, but generally applicable to a much wider range of species of different growth types, both dicots and monocots and legumes and non-legumes.…”

Culture ofPlantagospecies as bioactive components resources: a 20-year review and recent applications

“…sand/soil/sawdust, soil/Turface ® /sand (Fajer et al, 1991), sand/Terragreen ® (Staddon et al, 1998(Staddon et al, , 1999Hodge et al, 2000), soil/peat/perlite (McCloud & Berenbaum, 2000).…”

“…are the most widely reported species in the literature. The seeds of Plantago used for most of the research programmes usually were provided from private collections (Staal et al, 1991) and Botanical Garden or Research Institute collections (Makowczynska & Andrzejewska-Golec, 2000;Budzianowska et al, 2004); they were also harvested locally from wild plants (Flanagan & Jefferies, 1989;Harvey, 1989;Rouhier & Read, 1998;McCloud & Berenbaum, 2000;Wolff et al, 2000) or purchased from industrial producers (Staddon et al, 1998(Staddon et al, , 1999Hodge et al, 2000).…”

“…The improvement of certain species is largely due to a greater understanding of the morphological, physiological and genomic particularities of the individual species (Sen Raychaudhuri & Pramanik, 1997). The study of Plantago in its natural environment must be related to the concomitant study of the surrounding ecology (Clauss & Venable, 2000;Lacey & Herr, 2000;Sanderson & Elwinger, 2000a,b), allelopathy (Newman & Rovira, 1975), plant and insect-host relations (Bowers & Stamp, 1993), plant-microorganisms interactions as with bacteria, viruses and mycorrhizal fungi (Baas & Kuiper, 1989;De Nooij & Mook, 1992;Verhagen et al, 1995;Staddon et al, 1998;Klironomos & Moutoglis, 1999;Byrne & Mitchell, 2004;Roesti et al, 2005;Blaszkowski et al, 2006), pollutants (Siegel & Siegel, 1975), ozone (Reiling & Davison, 1992;Whitfield et al, 1997;Zheng et al, 2000;Tonneijck et al, 2004), nutrition (Blacquière et al, 1988;Den Hertog et al, 1996), saline stress (Ferron et al, 1977;Jefferies et al, 1979;Königshofer, 1983;Flanagan & Jefferies, 1989;Harvey, 1989;Koyro, 2006).…”