Higher ROS scavenging ability and plasma membrane H+‐ATPase activity are associated with potassium retention in drought tolerant tea plants

Abstract Drought is one of the main limiting factors resulting in the reduction of yield and quality of tea production. Our previous studies indicated that K + retention was a key factor associated with alleviating drought‐induced damage in tea plants. However, the underlying mechanisms are still unclear. In the present study, drought tolerant tea plant (variety Zhongcha108) exhibited higher plasma membrane (PM) H + ‐ATPase activity and lower negative membrane potential compared with the drought sensitive tea plant (variety Ruanzhiwulong). In addition to superior mesophyll K + retention ability and higher PM H + ‐ATPase activity, the drought tolerant tea plant exhibited lower accumulation of reactive oxygen species (ROS) than the sensitive one. Moreover, exogenous supply of Na 3 VO 4 (plasma membrane H + ‐ATPase inhibitor) and H 2 O 2 (mimicking apoplastic ROS) resulted in a significantly higher K + efflux in the mesophyll of the drought sensitive tea plant than the non‐treated one. Taken together, the higher ROS scavenging ability and plasma membrane H + ‐ATPase activity were major factors contributing to the higher K + retention in drought tolerant tea plants.