Immunolocalization of plasma-membrane H+-ATPase and tonoplast-type pyrophosphatase in the plasma membrane of the sieve element-companion cell complex in the stem of Ricinus communis L.
Immunolocalization of plasma-membrane H+-ATPase and tonoplast-type pyrophosphatase in the plasma membrane of the sieve element-companion cell complex in the stem of Ricinus communis L.
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DOI：
10.1007/s004250000475
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发表时间：
2001-05-01
期刊：
影响因子：
4.3
通讯作者：
Ullrich, CI
中科院分区：
文献类型：
--
作者：
Langhans, M;Ratajczak, R;Ullrich, CI
以蓖麻2周龄茎为材料，研究了韧皮部中筛元-伴胞复合体质膜定位的初级泵。与西葫芦茎比较，西葫芦茎中的蛋白质含量明显高于西葫芦。根癌农杆菌诱导的冠瘿的次生韧皮部是典型的库组织。质膜（PM）H+ ATP酶和液泡膜型焦磷酸酶（PPase）的免疫荧光和共聚焦激光扫描显微镜（CLSM）单或双标记特异性单克隆抗体和多克隆抗体。通过CLSM的定量荧光评价揭示了在一个膜中的两个泵，筛元件PM。不同的PM H+-ATPase抗体克隆，提出了对PM H+-ATPase的玉米胚芽鞘，在小鼠中诱导和小鼠杂交瘤细胞中产生的，区分不同的韧皮部细胞类型。克隆30 D5 C4和44 B8 A1标记筛分子，克隆46 E5 B11 D5标记伴细胞，表明存在不同的韧皮部PM H+ ATPase亚型。结果进行了讨论，在检索泄漏的蔗糖，K+和氨基酸，作为一个未知的作用，ATP在SE中发现的SE转运蛋白。PPase的功能可能与韧皮部蔗糖代谢有关，以支持ATP需求过程。
Plasma-membrane-located primary pumps were investigated in the sieve element (SE)-companion cell complex in the transport phloem of 2-week-old stems of Ricinus communis L. and, for comparison, in stems of Cucurbita pepo L. and in the secondary phloem of Agrobacterium tumefaciens-induced crown galls as a typical sink tissue. The plasma-membrane (PM) H+ ATPase and the tonoplast-type pyrophosphatase (PPase) were immunolocalized by epifluorescence and confocal laser scanning microscopy (CLSM) upon single or double labeling with specific monoclonal and polyclonal antibodies. Quantitative fluorescence evaluation by CLSM revealed both pumps in one membrane, the sieve-element PM. Different PM H+-ATPase antibody clones, raised against the PM H+-ATPase of Zea mays coleoptiles, induced in mouse and produced in mouse hybridoma cells, discriminated between different phloem cell types. Clones 30D5C4 and 44B8A1 labeled sieve elements and clone 46E5B11D5 labeled companion cells, indicating the existence of different phloem PM H+ ATPase isoforms. The results are discussed in terms of energization of SE transporters for retrieval of leaking sucrose, K+ and amino acids, as one of the unknown roles of ATP found in SEs. The function of the PPase could be related to phloem sucrose metabolism in support of ATP-requiring processes.