
%0 Journal Article
%A Medina, E 
%A Osmond, CB 
%T Temperature Dependence of Dark CO<sub>2</sub> Fixation and Acid Accumulation in <I>Kalanchoe daigremontiana</I>
%J Functional Plant Biology
%D 1981/12/01
%V 8
%N 6
%P 641-649
%K 
%R https://doi.org/10.1071/PP9810641
%U https://www.publish.csiro.au/paper/PP9810641 
%X 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. 
