
TY  - JOUR
A1  - Osmond, CB 
T1  - Carbon Reduction and Photosystem II Deficiency in Leaves of C<sub>4</sub> Plants
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 1974
VL  - 1
IS  - 1
SP  - 41
EP  - 50
KW  - 
UR  - https://doi.org/10.1071/PP9740041 
N2  - The Hill reaction and photosystem I activity of chloroplasts isolated from mesophyll and bundle sheath cells of Atviplex spongiosa and Sorghum bicolov was measured using narrow-band, high-intensity illumination of 646, 712, and 730 nm. The photosystem I reactions (methylviologen Mehler reaction and diphenylcarbazone reduction) were equally active in 646 and 712 nm light, whereas Hill activity was reduced by 70% in 712 nm light relative to 646 nm. Intact leaves were illuminated with 646 nm light and exposed to a pulse of 14CO2. The pulse was followed by a chase in 646,712, or 730 nm light or in darkness. In A. spongiosa leaves the movement of carbon from C4 acids to carbohydrates during the chase period only occurred to a significant extent in 646 nm light. In S. bicolor leaves, 712 nm light was almost as effective as 646 nm light in inducing the movement of carbon from C4 acids to carbohydrate. Evidently in this species carbon reduction is not entirely dependent on concurrent photosystem I + II activity for the provision of reducing potential. The data are discussed in relation to the deficiency of photosystem II activity in bundle sheath cells of S. bicolor. 
ER  -

