IMMUNOLOCALIZATION OF THE PLASMA-MEMBRANE H+-ATPASE IN MINOR VEINS OF VICIA-FABA IN RELATION TO PHLOEM LOADING
IMMUNOLOCALIZATION OF THE PLASMA-MEMBRANE H+-ATPASE IN MINOR VEINS OF VICIA-FABA IN RELATION TO PHLOEM LOADING
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DOI：
10.1104/pp.105.2.691
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发表时间：
1994-06-01
期刊：
影响因子：
7.4
通讯作者：
BONNEMAIN, JL
中科院分区：
文献类型：
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作者：
BOUCHEPILLON, S;FLEURATLESSARD, P;BONNEMAIN, JL
通过电子显微镜研究了质膜 H+-ATP 酶的免疫定位，该酶产生质子动力，为无机和有机溶质的吸收提供能量。研究的细胞位于蚕豆输出叶子的小静脉中，韧皮部转移细胞从质外体中吸收光合产物。免疫学可检测到的 H+-ATP 酶在不同细胞类型之间存在差异，并且转移细胞中的 H+-ATP 酶比其他细胞类型中的密度要高得多，特别是在筛管中。此外，H+-ATP酶在转移细胞中的分布并不均匀，该泵更集中在邻近束鞘、韧皮部薄壁组织和木质部导管的区域，而不是沿着筛管边界的壁的光滑部分。这些结果表明，转移细胞的质膜折叠具有质子泵送机制，可以为韧皮部质外体中光合产物的有效摄取和从维管汁液中有效回收含氮化合物提供能量。
The immunolocalization of the plasma membrane H+-ATPase, which generates a proton motive force energizing the uptake of inorganic and organic solutes, was studied by electron microscopy. The cells studied were in minor veins of Vicia faba L. exporting leaves, where photosynthates are supposed to be absorbed from the apoplast by phloem transfer cells. Immunologically detectable H+-ATPase varied among the different cell types and was considerably denser in the transfer cells than in the other cell types, particularly in the sieve tube. Moreover, the distribution of the H+-ATPase was not homogeneous in transfer cells, that pump being more concentrated in the region adjacent to the bundle sheath, phloem parenchyma, and xylem vessels than along the smooth part of the wall bordering the sieve tube. These results show that the plasma membrane infoldings of transfer cells possess the proton-pumping machinery required to energize an efficient uptake of photosynthates from the phloem apoplast and an efficient retrieval of nitrogenous compounds from the vascular sap.