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 Na₃VO₄ (plasma membrane H⁺‐ATPase inhibitor) and H₂O₂ (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.

中文翻译：

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较高的ROS清除能力和质膜H + -ATPase活性与耐旱茶树中的钾保留相关

干旱是导致茶叶产量和质量下降的主要限制因素之一。我们以往的研究表明，ķ ⁺保留了在茶树缓解干旱引起的损伤相关的关键因素。但是，其潜在机制仍不清楚。在本研究中，与干旱敏感的茶树（品种阮之五龙）相比，耐旱的茶树（品种Zhongcha108）表现出更高的质膜（PM）H ⁺ -ATPase活性和更低的负膜电位。除了优异的叶肉K ⁺保留能力和更高的PM H ⁺‐ATPase活性，耐旱茶树的活性氧（ROS）积累比敏感茶低。此外，Na ₃ VO ₄（质膜H ⁺ -ATPase抑制剂）和H ₂ O ₂（模仿质外生ROS）的外源供应导致干旱敏感茶树的叶肉中的K ⁺外排比未处理的高得多。一。综上所述，较高的ROS清除能力和质膜H ⁺ -ATPase活性是导致耐旱茶树中较高K ⁺保留的主要因素。