Abstract
Responses of respiratory system to low P condition have been investigated using cultured cells, but differences in responses of respiration between shoot and root are still unknown. We hydroponically cultivated spinach in low (1 μM, LP) and high P conditions (50 μM, HP), and examined responses of respiratory systems in shoot and root separately. Respiratory rates on the FW basis did not change during the cultivation, but cyanide-resistant respiratory rates gradually increased, particularly in LP leaves. We isolated mitochondria from leaves and roots, and examined components of the electron transport and enzymes of the TCA cycle. We also examined enzymes of the glycolysis. The responses of the electron transport to low P are similar in leaves and roots, but those of the TCA-cycle enzymes are different between leaves and shoots.
