Kluge Christoph, Lamkemeyer Petra, Tavakoli Nastaran, Golldack Dortje, Kandlbinder Andrea, Dietz Karl-Josef
Department of Physiology and Biochemistry of Plants, University of Bielefeld, Germany.
Mol Membr Biol. 2003 Apr-Jun;20(2):171-83. doi: 10.1080/0968768031000084154.
The vacuolar-type ATPase (V-ATPase) and the vacuolar H(+)-pyrophosphatase are electrogenic proton pumps at plant endomembranes that create the proton motive force required for secondary activated transport and metabolite accumulation during development and adaptation to a variety of adverse growth conditions. Twelve distinct vacuolar H(+)-ATPase (VHA) subunits are suggested to constitute the functional V-ATPase complex. Starting from the available expressed sequence tag (EST) sequences and by homology screening, the complete set of 12 VHA subunits was cloned as cDNAs from the halophyte Mesembryanthemum crystallinum, vha-A-H, -a,-c, -d and -e. Transcript levels of all 12 VHA subunits as well as of tonoplast pyrophosphatase and P-ATPase were analysed in root and leaf tissue under conditions of osmotic (700 mM mannitol), heat and cold stress, and salinity. Distinct coordinated changes of stress-induced expression were observed for most subunits in roots and leaves, with mostly paralleled changes in transcript levels of all subunits. In some cases, contrasting responses were seen for vha-B and -c transcript amounts.
液泡型ATP酶（V-ATP酶）和液泡H⁺-焦磷酸酶是植物内膜上的生电质子泵，它们在植物发育以及适应各种不利生长条件的过程中，产生次级主动运输和代谢物积累所需的质子动力。据推测，12种不同的液泡H⁺-ATP酶（VHA）亚基构成了功能性V-ATP酶复合体。从现有的表达序列标签（EST）序列出发，通过同源性筛选，从盐生植物冰叶日中花中克隆出了全套12个VHA亚基的cDNA，即vha-A-H、-a、-c、-d和-e。在渗透（700 mM甘露醇）、热、冷胁迫和盐胁迫条件下，分析了根和叶组织中所有12个VHA亚基以及液泡膜焦磷酸酶和P-ATP酶的转录水平。在根和叶中，大多数亚基都观察到了胁迫诱导表达的明显协同变化，所有亚基的转录水平大多平行变化。在某些情况下，vha-B和-c的转录量呈现出相反的反应。
