Department of Horticulture, Purdue University, WesiLafayette, IN 47907, USA.
Plant J. 1993 May;3(5):637-46.
Cells of tobacco adapted to grow in high concentrations of NaCl develop tight zones of adhesion between the plasma membrane and cell wall, revealed by concave plasmolysis in osmotic solutions. Unadapted cells exhibit mostly convex plasmolysis and exhibit little or no adhesive character. Wall-less protoplasts isolated from the adapted cells retain the complementary adhesive character and adhere tightly to each other, whereas protoplasts from unadapted cells do not. The hexapeptide gly-arg-gly-asp-ser-pro, in which the arg-gly-asp represents the integrin-binding domain of several animal extracellular matrix proteins,specifically blocks adhesion of the protoplasts. A control hexapeptide, gly-arg-gly-glu-ser-pro, is ineffective in blocking adhesion. Tobacco proteins immunologically related to human vitronectin were found in cell walls and membranes of unadapted and NaCI adapted cells, but the total extractable vitronectin-like protein was enriched in the adapted cells. Tobacco proteins immunologically related to human fibronectin were found in membranes and cell walls of NaCI adapted cells but not in those from unadapted cells.Our observations indicate that plant cells possess cell-matrix adhesion complexes similar to animal cells, and these adhesion complexes accumulate ingrowth-limited cells adapted to saline stress.
经盐胁迫驯化的烟草细胞在质膜和细胞壁之间形成紧密的附着区，在高渗溶液中会发生凹陷质壁分离。未驯化的细胞主要发生外凸质壁分离，附着性差或几乎没有附着性。从驯化细胞中分离得到的无壁原生质体保留了互补的附着特性，并紧密附着在一起，而未驯化细胞的原生质体则不会。六肽 Gly-Arg-Gly-Asp-Ser-Pro 中 Arg-Gly-Asp 是几种动物细胞外基质蛋白的整联蛋白结合域，特异性阻断原生质体的附着。对照六肽 Gly-Arg-Gly-Glu-Ser-Pro 则不能阻断附着。在未驯化和经 NaCl 驯化的细胞的细胞壁和质膜中发现了与人类玻连蛋白免疫相关的烟草蛋白，但可提取的玻连蛋白样蛋白在驯化细胞中富集。在经 NaCl 驯化的细胞的质膜和细胞壁中发现了与人类纤维连接蛋白免疫相关的烟草蛋白，但在未驯化的细胞中没有发现。我们的观察表明，植物细胞具有与动物细胞相似的细胞基质附着复合物，这些附着复合物在适应盐胁迫的生长受限细胞中积累。
