Activities of some enzymes related to carbon metabolism were studied in different ecotypes of Rumex nepalensis growing at 1 300, 2 250, and 3 250 m above mean sea level. Activities of ribulose-1,5-bisphosphate carboxylase/oxygenase, phosphoenolpyruvate carboxylase, aspartate aminotransferase, and glutamine synthetase increased with altitude, whereas activities of malate dehydrogenase, NAD-malic enzyme, and citrate synthase did not show a significant difference with change in altitude. and N. Kumar ... [et al.].
The effects of metabolisable sugars sucrose and glucose along with non-metabolisable isomers of sucrose palatinose and turanose were tested. Rate of oxygen evolution (P), electron transport rate (ETR), and photochemical quenching (qp) showed substantial decrease after 24 and 48 h by glucose and sucrose treatments, whereas there was no effect on all these parameters by the treatment with palatinose and turanose. Also the Fv/Fm ratio remained constant through the time of studies revealing that the maximal photochemical capacity of the cells was unchanged. Non-photochemical quenching (qN) showed a decrease compared to the control values by all the treatments. Hence P and Chl fluorescence parameter were affected only by those sugars which are used in the metabolic pathways and not by sugar analogues. and A. K. Sinha, T. Roitsch.