
TY  - JOUR
A1  - Esashi, Y 
A1  - Ooshima, Y 
A1  - Abe, M 
A1  - Kurota, A 
A1  - Satoh, S 
T1  - CO<sub>2</sub>-enhanced C<sub>2</sub>H<sub>4</sub> Production in Tissues of Imbibed Cocklebur Seeds
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 1986
VL  - 13
IS  - 3
SP  - 417
EP  - 429
KW  - 
UR  - https://doi.org/10.1071/PP9860417 
N2  - Both endogenous C2H4 production and the conversion of 1-aminocyclopropane-1-carboxylic acid (ACC) to C2H4 in the axial tissues of upper cocklebur (Xanthium pennsylvanicum Wallr.) seeds were enhanced by CO2, and this enhancement was accompanied by increased axial growth. However, in the seed-coat (endosperm layer), which had no growth potential, the endogenous C2H4 production was preferentially promoted by CO2. CO2 increased the content of ACC in both tissues. The maximal ACC-C2H4 conversion in the axial tissue occurred at CO2 concentrations that varied from 1 to 10%, depending upon the O2 tension of the ambient atmosphere. Similar to the inhibition of seed respiration by NaN3, the ACC-C2H4 conversion was more strongly inhibited by KCN or NaN3 in the presence of CO2 than in its absence. This suggests an increased involvement of the cytochrome path in cocklebur seed respiration in the presence of CO2. This suggestion was supported by data showing that CO2 elevated the ATP level in the axial tissues. Little CO2-enhancement of the ACC-C2H2 conversion occurred when the ATP level of seeds had been reduced by KCN pretreatment and maintained low in a hypoxia during a subsequent incubation period. These results suggested that CO2 enhances C2H4 production of imbibed cocklebur seeds in two different ways: through both increases of ACC supply and of ACC-C2H2 conversion, probably resulting from the CO2-induced increase in the cytochrome path flux or in the resultant ATP level. 
ER  -

