Carbon dioxide concentrations are very high in developing oilseeds.
A new method has been developed to rapidly determine the total inorganic carbon concentration (gaseous [CO2] + aqueous [CO(2)] + [HCO3-] + [CO3(2)-]) in developing seeds. Seeds are rapidly dissected and homogenized in 1 N HCl in gas-tight vials. The headspace gas is then analyzed by infrared gas analysis. Developing rapeseed (Brassica napus L.) and soybean [Glycine max (L.) Merr.] seeds were analyzed and found to have up to 40 and 12 mM total inorganic carbon, respectively. These concentrations are ca. 600-2000-fold higher than in ambient air or values reported for leaves. Carbon dioxide concentrations in rapeseed peaked during the stage of maximum oil synthesis and declined as seeds matured. The consequences for seed metabolism, physiology and carbon economy are discussed.
Goffman
Fernando D
FD
Department of Plant Biology, Room S-346, Michigan State University, East Lansing, MI 48824, USA. goffman@msu.edu
Ruckle
Mike
M
Ohlrogge
John
J
Shachar-Hill
Yair
Y
D029741:Brassica rapa / Q000737:chemistry / Q000254:growth & development*; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism*; D005740:Gases / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D012639:Seeds / Q000737:chemistry / Q000254:growth & development*; D013025:Glycine max / Q000737:chemistry / Q000254:growth & development*; D013055:Spectrophotometry, Infrared
D005740:Gases; D002245:Carbon Dioxide