Winter-Sluiter E, Läuchli A, Kramer D
Institut für Botanik, Technische Hoschschule Darmstadt, D-6100 Darmstadt, Federal Republic of Germany.
Plant Physiol. 1977 Dec;60(6):923-7. doi: 10.1104/pp.60.6.923.
ATPase activity in xylem parenchyma cells of barley (Hordeum vulgare L.) roots was demonstrated cytochemically with a lead precipitation reaction. The methodical parameters of this cytochemical test were optimized for distinction between ATPase-specific and nonspecific precipitates. Optimum conditions were prefixation in 1% glutaraldehyde for 1 hour and incubation for 2 hours in a medium containing 2 mm each of ATP, Ca(2+), and Pb(2+) at pH 7 and 25 C. Problems of cytochemical localizations are discussed.ATPase activity occurred mainly at the plasmalemma, the endoplasmic reticulum nuclear envelope, and outer mitochondrial membranes of xylem parenchyma cells. The tonoplast of these cells showed only little ATPase activity. High K(+) concentrations stimulated ATPase activity, particularly at the plasmalemma. Diethylstilbestrol prevented the formation of ATPase-specific precipitates. The cytochemical demonstration of a K(+)-stimulated ATPase at the plasmalemma of xylem parenchyma cells is discussed in relation to the possible role of this membrane in ion transport to the vessels.
利用铅沉淀反应，通过细胞化学方法证明了大麦（Hordeum vulgare L.）根木质部薄壁细胞中的ATP酶活性。针对区分ATP酶特异性沉淀和非特异性沉淀，对该细胞化学试验的方法参数进行了优化。最佳条件为在1%戊二醛中预固定1小时，并在pH值为7、温度为25℃、含有2 mM ATP、Ca(2+)和Pb(2+)的培养基中孵育2小时。讨论了细胞化学定位的问题。ATP酶活性主要出现在木质部薄壁细胞的质膜、内质网、核膜和线粒体外膜上。这些细胞的液泡膜仅显示出很少的ATP酶活性。高钾浓度刺激ATP酶活性，特别是在质膜处。己烯雌酚可阻止ATP酶特异性沉淀的形成。结合该膜在离子向导管运输中的可能作用，讨论了在木质部薄壁细胞质膜上钾刺激的ATP酶的细胞化学证明。
