Qifu M A, Rengel Zdenko, Kuo John
Soil Science and Plant Nutrition, University of Western Australia, Crawley, Australia.
Ann Bot. 2002 Feb;89(2):241-4. doi: 10.1093/aob/mcf017.
Aluminium (Al) toxicity in rye (Secale cereale L.), an Al-resistant crop, was examined by measuring root elongation and cytoplasmic free activity of calcium ([Ca2+]cyt) in intact root apical cells. Measurement of [Ca2+]cyt, was achieved by loading a Ca2+-sensitive fluorescent probe. Fluo-3/AM ester, into root apical cells followed by detection of intracellular fluorescence using a confocal laser scanning microscope. After 20 min of exposure to 50 microM Al (pH 4-2) a slight increase in [Ca2+]cyt of root apical cells was observed, while the response of [Ca2+]cyt to 100 microM Al (pH 4.2) was faster and larger ([Ca2+]cyt increased by 46% in 10 min). Increases in [Ca2+]cyt were correlated with inhibition of root growth, generally measurable after 2 h. Addition of 400 microM malic acid (pH 4.2) largely ameliorated the effect of 100 microM Al on [Ca2+]cyt in root apical cells and protected root growth from Al toxicity. These results suggest that an increase in [Ca2+]cyt in root apical cells in rye is an early effect of Al toxicity and is followed by the secondary effect on root elongation.
通过测量完整根尖细胞中的根伸长和细胞质游离钙活性（[Ca2+]cyt），研究了抗铝作物黑麦（Secale cereale L.）中的铝（Al）毒性。通过将Ca2+敏感荧光探针Fluo-3/AM酯加载到根尖细胞中，然后使用共聚焦激光扫描显微镜检测细胞内荧光，来实现[Ca2+]cyt的测量。暴露于50 microM Al（pH 4.2）20分钟后，观察到根尖细胞的[Ca2+]cyt略有增加，而[Ca2+]cyt对100 microM Al（pH 4.2）的反应更快且更大（10分钟内[Ca2+]cyt增加了46%）。[Ca2+]cyt的增加与根生长的抑制相关，通常在2小时后可测量。添加400 microM苹果酸（pH 4.2）在很大程度上改善了100 microM Al对根尖细胞中[Ca2+]cyt的影响，并保护根生长免受铝毒性影响。这些结果表明，黑麦根尖细胞中[Ca2+]cyt的增加是铝毒性的早期效应，随后是对根伸长的次级效应。
