Blue light-induced kinetics of H+ and Ca2+ fluxes in etiolated wild-type and phototropin-mutant Arabidopsis seedlings
Blue light-induced kinetics of H+ and Ca2+ fluxes in etiolated wild-type and phototropin-mutant Arabidopsis seedlings
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DOI：
10.1073/pnas.042294599
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发表时间：
2002-02-19
影响因子：
11.1
通讯作者：
Shabala, S
中科院分区：
文献类型：
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作者：
Babourina, O;Newman, I;Shabala, S
利用MIFE非侵入式离子选择性微电极技术研究了蓝光处理下拟南芥两个野生型（WT）和phot 1、phot 2及phot 1/phot 2突变体的离子流动力学。BL引起的H+和Ca 2+转运蛋白的活性显着变化的第一个10分钟内BL发病，峰值之间的3和5分钟。在所有WT植物和phot 2突变体，BL诱导立即Ca 2+内流。在phot 1和phot 1 phot 2突变体中，净Ca 2+通量保持稳定。这表明，PHOT 1调节Ca ~（2+）从质外体吸收到细胞质中。离子通量的变化进行了测量，从子叶的完整的幼苗和从切断顶端的下胚轴去头的幼苗。因此，光感受器介导BL诱导的Ca ~（2+）和H ~+通量存在于其余的去头幼苗中，并且可能也存在于子叶中。H+和Ca 2+通量对BL的响应似乎没有联系，因为：（i）当观察到两种离子的变化时，Ca 2+通量几乎立即发生变化，而H+通量滞后约1.5分钟;（h）在Wassilewskija生态型中，H+通量的变化很小。最后，观察到波形变化的Ca 2+和H+浓度沿着子叶钩轴，无论其方向的光。
Ion flux kinetics associated with blue light (BL) treatment of two wild types (WTs) and the phot1, phot2 and phot1/phot2 mutants of Arabidopsis were studied by using the MIFE noninvasive ionselective microelectrode technique. BL induced significant changes in activity of H+ and Ca2+ transporters within the first 10 min of BL onset, peaking between 3 and 5 min. In all WT plants and in phot2 mutants, BL induced immediate Ca2+ influx. In phot1 and phot1 phot2 mutants, net Ca2+ flux remained steady. It is suggested that PHOT1 regulates Ca2+ uptake into the cytoplasm from the apoplast. Changes in ion fluxes were measured from cotyledons of intact seedlings and from the cut top of the hypocotyl of decapitated seedlings. Thus the photoreceptors mediating BL-induced Ca2+ and H+ fluxes are present in the rest of the decapitated seedling and probably in the cotyledons as well. The H+ and Ca2+ flux responses to BL appear not to be linked because, (i) when changes were observed for both ions, Ca2+ flux changed almost immediately, whereas H+ flux lagged by about 1.5 min; (h) in the Wassilewskija ecotype, changes in H+ fluxes were small. Finally, wave-like changes in Ca2+ and H+ concentrations were observed along the cotyledon-hook axis regardless of its orientation to the light.