Engstrom Eric M, Ehrhardt David W, Mitra Raka M, Long Sharon R
Howard Hughes Medical Institute, Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020, USA.
Plant Physiol. 2002 Apr;128(4):1390-401. doi: 10.1104/pp.010691.
Bacterial Nod factors trigger a number of cellular responses in root hairs of compatible legume hosts, which include periodic, transient increases in cytosolic calcium levels, termed calcium spiking. We screened 13 pharmaceutical modulators of eukaryotic signal transduction for effects on Nod factor-induced calcium spiking. The purpose of this screening was 2-fold: to implicate enzymes required for Nod factor-induced calcium spiking in Medicago sp., and to identify inhibitors of calcium spiking suitable for correlating calcium spiking to other Nod factor responses to begin to understand the function of calcium spiking in Nod factor signal transduction. 2-Aminoethoxydiphenylborate, caffeine, cyclopiazonic acid (CPA), 2,5-di-(t-butyl)-1,4-hydroquinone, and U-73122 inhibit Nod factor-induced calcium spiking. CPA and U-73122 are inhibitors of plant type IIA calcium pumps and phospholipase C, respectively, and implicate the requirement for these enzymes in Nod factor-induced calcium spiking. CPA and U-73122 inhibit Nod factor-induced calcium spiking robustly at concentrations with no apparent toxicity to root hairs, making CPA and U-73122 suitable for testing whether calcium spiking is causal to subsequent Nod factor responses.
细菌结瘤因子在亲和豆科宿主植物的根毛中引发多种细胞反应，其中包括胞质钙水平的周期性短暂升高，即所谓的钙峰。我们筛选了13种真核信号转导的药物调节剂，以研究其对结瘤因子诱导的钙峰的影响。此次筛选有两个目的：一是确定蒺藜苜蓿中结瘤因子诱导钙峰所需的酶，二是鉴定适合将钙峰与其他结瘤因子反应相关联的钙峰抑制剂，从而开始了解钙峰在结瘤因子信号转导中的作用。2-氨基乙氧基二苯硼酸、咖啡因、环匹阿尼酸（CPA）、2,5-二叔丁基对苯二酚和U-73122可抑制结瘤因子诱导的钙峰。CPA和U-73122分别是植物IIA型钙泵和磷脂酶C的抑制剂，这表明这些酶在结瘤因子诱导的钙峰过程中是必需的。CPA和U-73122在对根毛无明显毒性的浓度下能强烈抑制结瘤因子诱导的钙峰，这使得CPA和U-73122适用于测试钙峰是否是后续结瘤因子反应的原因。
