Abstract
Aboveground growth of C4plants responds more strongly to atmospheric CO2 concentration when soil water is limiting rather than abundant. Whether the same is true of root growth and morphology, however, remains to be evaluated. We investigated interactive effects of CO2 and soil water on root growth and morphology of two C4 grasses. Seedlings of the dominant C4 grasses from tallgrass prairie, Schizachyrium scoparium and Andropogon gerardii, were grown for 8 weeks in an elongated, controlled environment chamber at CO2 concentrations of 368 (ambient) and 203 (subambient) μmol mol−1. Seedlings were maintained at either high (ca. 90%) or low (ca. 50%) soil relative water holding capacity (RWC). Both root and shoot systems of C4 grass seedlings responded similarly to CO2 enrichment irrespective of whether soil water was limiting or abundant. Root growth was affected primarily by increased RWC (40–51% increases) and secondarily by higher CO2 (15–27% increases). The relative distribution of root surface area, number of root tips and length and volume of roots were significantly affected by CO2 enrichment with proportional increases of 55–61%, 39-52%, 50–55% and 53–58%, respectively, occurring in very fine (0–0.3 mm) roots. The indirect effect of CO2 enrichment on conservation of soil water in grasslands may be as important as direct photosynthetic response effects in the CO2-induced enhancement of whole-plant growth in C4 grasses.
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References
BassiriRad H, Reynolds J F, Virginia R A and Brunelle M H 1997 Growth and root NO_ 3 and PO3_ 4 uptake capacity of three desert species in response to atmospheric CO2 enrichment. Aust. J. Plant. Phys. 24, 353–358.
Bouma T J, Nielsen K L and Koutstall B 2000 Sample preparation and scanning protocol for computerized analysis of root length and diameter. Plant Soil 218, 185–196.
Cerling T E, Ehleringer J R and Harris J M 1998 Carbon dioxide starvation, the development of C4 ecosystems and mammalian evolution. Phil. Trans. Royal Soc. London 353, 159–171.
Cerling T E, Harris J M, MacFadden B J, Leakey M G, Quade J, Eisenmann V and Ehleringer J R 1997 Global vegetation change through the Miocene/Pliocene boundary. Nature 389, 153–158.
Ehleringer J R, Curling T E and Helliker B R 1997 C4 photosynthesis, atmospheric CO2, and climate. Oecologia 112, 285–299.
Ehleringer J R, Sage R F, Flanagan L B and Pearcy R W 1991 Climate change and the evolution of C4 photosynthesis. Trends Ecol. Evol. 6, 95–99.
Ghannoum O, Von Caemmerer S, Barlow E W R and Conroy J P 1997 The effect of CO2 enrichment and irradiance on the growth, morphology and gas exchange of a C3 (Panicum laxum) and C4 (Panicum antitodale) grass. Aust. J. Plant. Phys. 24, 227–237.
He H, Kirkham M B, Lawlor D J and Kanemasu E T 1992 Photosynthesis and water relations of big bluestem (C4) and Kentucky bluegrass (C3) under high concentration of carbon dioxide. Trans. Kansas Acad. Sci. 95, 139–152.
Hoagland D R and Arnon D I 1950 The water-culture method for growing plants without soil. Calif. Ag. Exper. Sta. Circ. 347, 1–39.
Howden S M, McKeon G M, Carter J O and Beswick A 1999 Potential global change impacts on C3-C4 grass distributions in eastern Australian rangelands. In VIth International Rangeland Congresss Proceedings Vol. 1 Eds. D Eldridge and D Freudenberger. pp 41–43. Fyshwick, ACT, Australia: Elect Printing.
Huckabee J W Jr, Thompson D R, Wyrick J C and Paulat E g 1977. Soil Survey Bell County Texas. USDA Soil Conservation Service, Washington, D.C. USA. 165 pp.
Hunt HW, Elliott E T, Detling J K, Morgan J A and Chen D X 1996 Responses of a C3 and C4 perennial grass to elevated CO2 and temperature under different water regimes. Global Change Biol. 2, 35–47.
Jacobs B F, Kingston J D and Jacobs L L 1999 The origin of grassdominated ecosystems. Ann. Miss. Bot. Gard. 86, 590–643.
Knapp A K, Hamerlynck E P and Owensby C E 1993 Photosynthesis and water relations responses to elevated CO2 in the C4 grass Andropogon gerardii. Int. J. Plant. Sci. 154, 459–466.
LeCain D R and Morgan J A 1998 Growth, leaf nitrogen and leaf carbohydrate concentrations respond differently to elevated CO2 in NAD-ME and NADP-ME C4 grasses. Phys. Plant. 102, 297–306.
Mayeux H S, Johnson H B, Polley H W, Dumesnil M J and Spanel G A 1993 A controlled environment chamber for growing plant across a subambient CO2 gradient. Funct. Ecol. 7, 125–133.
Morgan J A, LeCain D R, Read J J, Hunt HW and Knight WG 1998 Photosynthetic pathway and ontogeny affect water relations and the impact of CO2on Bouteloua gracilis (C4) and Pascopyrum smithii (C3). Oecologia 114, 483–493.
Morgan J A, Hunt H W, Monz C A and LeCain D R 1994 Consequences of growth at two carbon dioxide concentrations and two temperatures for leaf gas exchange in Pascopyrum smithii (C3) and Bouteloua gracilis (C4). Plant Cell. Environ. 17, 1023–1033.
Norby R J 1994 Issues and perspectives for investigating root responses to elevated atmospheric carbon dioxide. Plant Soil 165, 9–20.
Norby R J and Jackson R B 2000 Root dynamics and global change: seeking an ecosystem perspective. New Phytol. 147, 3–12.
Owensby C E, Ham J M, Knapp A K and Auen L m 1999 Biomass production and species composition change in a tallgrass prairie ecosystem after long-term exposure to elevated atmospheric CO2. Global Change Biol. 5, 497–506.
Owensby C E, Coyne P I, Ham JM, Auen L A and Knapp A K 1993 Biomass production in a tallgrass prairie ecosystem exposed to ambient and elevated CO2. Ecol. Appl. 3, 644–653.
Pagani N, Freeman K H and Arthur M A 1999 Late Miocene atmospheric CO2 concentrations and the expansion of C4 grasses. Science 285, 876–879.
Poorter H 1993 Interspecific variation in the growth response of plants to an elevated CO2 concentration. Vegetatio 104/105, 77–97.
Read J, Morgan J A, Chatterton N J and Harrison P A 1997 Gas exchange and carbohydrate and nitrogen concentrations in leaves of Pascopyrum smithii (C3) and Bouteloua gracilis (C4) at different carbon dioxide concentrations and temperatures. Ann. Bot. 79, 197–206.
Rogers H H, Runion G B and Krupa S V 1994 Plant responses to atmospheric CO2 enrichment with emphasis on roots and the rhizosphere. Envrion. Pollut. 83, 155–189.
Sionit N and Patterson D T 1985 Responses of C4 grasses to atmospheric CO2 enrichment. II. Effect of water stress. Crop Sci. 25, 533–537.
Sionit N and Patterson D T 1984 Responses of C4 grasses to atmospheric CO2 enrichment. I. Effect of irradiance. Oecologia 65, 30–34.
Wand S J E, Midgley G F, Jones M H and Curtis P S 1999 Responses of wild C4 and C3 grass (Poaceae) species to elevated atmospheric CO2 concentration: a meta-analytic test of current theories and perceptions. Global Change Biol. 5, 723–741.
Ward J K, Tissue D T, Thomas R B and Strain B R 1999 Comparative responses of model C3 and C4 plants to drought in low and elevated CO2. Global Change Biol. 5, 857–867.
Watling J R and Press M C 1998 How does the C4 grass Eragrostis pilosa respond to elevated carbon dioxide and infection with the parasitic angiosperm Striga hermonthica New Phytol. 140, 667–675.
Wechsung G, Wechsung F, Wall G W, Adamsen F J, Kimball B A, Pinter Jr P J, Lamorte R L, Garcia R L and Hartschall TH 1999 The effects of free-air CO2 enrichment and soil water availability on spatial and seasonal patterns of wheat root growth. Global Change Biol. 5, 519–529.
Yoder C K, Vivin P, Defalco L A, Seemann J R and Nowak R S 2000 Root growth and function of three Mojave Desert grasses in response to elevated atmospheric CO2 concentration. New Phytol 145, 245–256.
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Derner, J., Polley, H., Johnson, H. et al. Root system response of C4 grass seedlings to CO2 and soil water. Plant and Soil 231, 97–104 (2001). https://doi.org/10.1023/A:1010306720328
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DOI: https://doi.org/10.1023/A:1010306720328