
TY  - JOUR
A1  - Medina, E 
A1  - Osmond, CB 
T1  - Temperature Dependence of Dark CO<sub>2</sub> Fixation and Acid Accumulation in <I>Kalanchoe daigremontiana</I>
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 1981
VL  - 8
IS  - 6
SP  - 641
EP  - 649
KW  - 
UR  - https://doi.org/10.1071/PP9810641 
N2  - Kalanchoe daigremontiana was grown at 25/15 and 34/24&#176;C and net CO2 fixation and acid synthesis were measured at 8, 15 and 24&#176;. The ratio of net dark CO2 fixation to acid accumulation was nearly 1 at all temperatures tested. Although the increased contribution of respiratory CO2 to total acid synthesis at high temperatures was demonstrated by incubating leaf discs in CO2-free air, it was not enough to account for the reduction of dark CO2 fixation. Plants grown at 25/15&#176; temperature regime showed maximal rates of nocturnal acid accumulation at 15&#176;, the rates decreasing markedly at 24&#176;. Plants grown at 24/34&#176; showed similar rates at 15 and 24&#176;, but acid accumulation was significantly lower at 8&#176;. Measurements of dark acid accumulation in CO2-free air indicated that 34/24&#176; plants have reduced respiration rates in comparison with 25/15&#176; plants. These observations are discussed in relation to hypotheses seeking to account for effects of temperature on crassulacean acid metabolism. 
ER  -

