Alteration of transport activity of proton pumps in coleoptile cells during early development stages of maize seedlings

摘要

Comparative analysis of the transport activity of proton pumps (plasmalemma H+ ATPase, vac uolar H+ ATPase, and vacuolar H+ pyrophosphatase) in the membrane preparations obtained from coleop tile cells of etiolated maize seedlings (Zea mays L.) was carried out. The highest level of vacuolar pyrophos phatase activity was observed during the early development of coleoptile cells under growth intensification through the elongation. The role of ATPase pumps of tonoplast and plasmalemma in the transport of hydro gen ions increases during further development. The plasmalemma activity in this process is higher. When the growth stops, the activity of proton pumps becomes significantly lower. Nevertheless, their substrate specific ity and sensitivity to proton pump inhibitors do not change, which can be an evidence of physiological signif icance of pumps in the maintenance of cell homeostasis.