Substrate regulation of root respiration during prolonged darkness in Arabidopsis and Hordeum plants

Arabidopsis thaliana (WT and TC265) and Hordeum vulgare plants were subjected to prolonged darkness. Roots were incubated for up to eight hours after excision in the presence or absence of sucrose, during prolonged dark treatment. The respiration was measured to test whether long-term supply of sucrose would result in an increase in the respiratory capacity. Incubating the pre-darkened roots for 0–8 h with sucrose increased the root respiration. These results are discussed in relation to the role of sugars in inducing gene expression.