Temperature dependence of respiration in roots colonized by arbuscular mycorrhizal fungi.
* The arbuscular mycorrhizal (AM) symbiosis is ubiquitous, and the fungus represents a major pathway for carbon movement in the soil-plant system. Here, we investigated the impacts of AM colonization of Plantago lanceolata and temperature on the regulation of root respiration (R). * Warm-grown AM plants exhibited higher rates of R than did nonAM plants, irrespective of root mass. AM plants exhibited higher maximal rates of R (R(max)-R measured in the presence of an uncoupler and exogenous substrate) and greater proportional use of R(max) as a result of increased energy demand and/or substrate supply. The higher R values exhibited by AM plants were not associated with higher maximal rates of cytochrome c oxidase (COX) or protein abundance of either the COX or the alternative oxidase. * Arbuscular mycorrhizal colonization had no effect on the short-term temperature dependence (Q(10)) of R. Cold-acclimated nonAM plants exhibited higher rates of R than their warm-grown nonAM counterparts. By contrast, chilling had a negligible effect on R of AM-plants. Thus, AM plants exhibited less cold acclimation than their nonAM counterparts. * Overall, these results highlight the way in which AM colonization alters the underlying components of respiratory metabolism and the response of root R to sustained changes in growth temperature.
Atkin
Owen K
OK
Department of Biology, The University of York, PO Box 373, York YO10 5YW, UK.
Sherlock
David
D
Department of Biology, The University of York, PO Box 373, York YO10 5YW, UK.
Fitter
Alastair H
AH
Department of Biology, The University of York, PO Box 373, York YO10 5YW, UK.
Jarvis
Susan
S
Department of Biology, The University of York, PO Box 373, York YO10 5YW, UK.
Hughes
John K
JK
Department of Biology, The University of York, PO Box 373, York YO10 5YW, UK.
Campbell
Catherine
C
Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-901 87 Umeå, Sweden.
Hurry
Vaughan
V
Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-901 87 Umeå, Sweden.
Hodge
Angela
A
Department of Biology, The University of York, PO Box 373, York YO10 5YW, UK.
D000064:Acclimatization; D019069:Cell Respiration; D015169:Colony Count, Microbial; D003576:Electron Transport Complex IV / Q000378:metabolism; D024101:Mitochondrial Proteins; D038821:Mycorrhizae / Q000254:growth & development / Q000502:physiology*; D009929:Organ Size; D010088:Oxidoreductases / Q000378:metabolism; D010940:Plant Proteins; D010943:Plantago / Q000166:cytology / Q000201:enzymology / Q000378:metabolism* / Q000382:microbiology*; D012044:Regression Analysis; D013559:Symbiosis; D013696:Temperature; D000099188:Alternative Oxidase
D003576:Electron Transport Complex IV; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D000099188:Alternative Oxidase; C038862:cytochrome o oxidase