Ca2+ transient induced by extracellular changes in osmotic pressure in Arabidopsis leaves:: differential involvement of cell wall-plasma membrane adhesion
Ca2+ transient induced by extracellular changes in osmotic pressure in Arabidopsis leaves:: differential involvement of cell wall-plasma membrane adhesion
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DOI：
10.1111/j.1365-3040.2005.01447.x
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发表时间：
2006-04-01
影响因子：
7.3
通讯作者：
Takagi, S
中科院分区：
文献类型：
--
作者：
Hayashi, T;Harada, A;Takagi, S
我们研究了苦草和转基因拟南芥（L.）嘿表达胞质水母发光蛋白。高渗和低渗治疗A. thaliana叶片各自快速诱导Ca 2+瞬变。这两种反应基本上依赖于细胞外Ca 2+的存在，并对Gd 3+敏感，Gd 3+是拉伸激活的Ca 2+通道的潜在阻断剂。在高渗处理引起的血浆置换和低渗处理引起的随后的血浆置换后，细胞对第二次高渗处理没有反应，并表现出质膜（PM）与细胞壁（CW）的粘附受损。反应性恢复约需6 h。相比之下，低渗治疗未观察到不应现象。纤维素酶预处理完全抑制高渗处理引起的钙瞬变，但不影响低渗处理的反应。用纤维素酶预处理的V. lapartea叶肉细胞表现出PM对CW的粘附受损。多细胞植物的叶细胞可以通过牵张激活的Ca ~（2+）通道对高渗和低渗处理作出反应，而PM对CW的纤维素酶敏感的粘附仅参与对高渗处理的反应。
We investigated the mechanism underlying the perception of extracellular changes in osmotic pressure in Vallisneria gigantea Graebner and transgenic Arabidopsis thaliana (L.) Heynh. expressing cytoplasmic aequorin. Hypertonic and hypotonic treatments of A. thaliana leaves each rapidly induced a Ca2+ transient. Both responses were essentially dependent on the presence of extracellular Ca2+ and were sensitive to Gd3+, a potential blocker of stretch-activated Ca2+ channels. Immediately after plasmolysis caused by hypertonic treatment and subsequent deplasmolysis caused by hypotonic treatment, the cells did not respond to a second hypertonic treatment and exhibited an impaired adhesion of the plasma membrane (PM) to the cell wall (CW). Recovery of the responsiveness required about 6 h. By contrast, no refractory phenomenon was observed in response to hypotonic treatment. Pretreatment with cellulase completely inhibited the Ca2+ transient induced by hypertonic treatment, but it did not affect the response to hypotonic treatment. V. gigantea mesophyll cells pretreated with cellulase exhibited an impaired adhesion of the PM to the CW. The leaf cells of multicellular plants can respond to both hypertonic and hypotonic treatments through the stretch-activated Ca2+ channels, whereas cellulase-sensitive adhesion of the PM to the CW is involved only in the response to hypertonic treatment.