Schaller A, Frasson D
Institute of Plant Sciences, ETH-Zürich, Switzerland.
Planta. 2001 Feb;212(3):431-5. doi: 10.1007/s004250000413.
Three ionophores were used to investigate a potential role of the plasma-membrane (PM) potential in the regulation of systemic wound-response gene expression in tomato (Lycopersicon escuilentum Mill.) plants. Valinomycin, nigericin, and gramicidin, which affect the PM potential by dissipating H+ and K+ gradients, respectively, induced the rapid accumulation of wound-response gene transcripts. Transcript induction by gramicidin was kinetically, qualitatively and quantitatively similar to systemin-induced transcript accumulation. On a molar basis, gramicidin and nigericin, which affect gradients of both H+ and K+, were more effective than the K+-selective valinomycin. Hyperpolarization of the PM by fusicoccin, on the other hand, repressed wound-response gene expression and, at the same time, induced salicylic acid (SA) accumulation and the expression of pathogenesis-related proteins. We show here that the inhibition of the wound response after fusicoccin treatment is not mediated by elevated concentrations of SA but is likely a direct effect of PM hyperpolarization. The data indicate a role for the PM potential in the differential regulation of wound and pathogen defense responses.
使用三种离子载体来研究质膜（PM）电位在番茄（Lycopersicon escuilentum Mill.）植株系统性伤口响应基因表达调控中的潜在作用。缬氨霉素、尼日利亚菌素和短杆菌肽分别通过耗散H⁺和K⁺梯度来影响PM电位，它们均可诱导伤口响应基因转录本的快速积累。短杆菌肽诱导的转录在动力学、定性和定量方面与系统素诱导的转录积累相似。在摩尔基础上，影响H⁺和K⁺梯度的短杆菌肽和尼日利亚菌素比K⁺选择性的缬氨霉素更有效。另一方面，壳梭孢菌素使质膜超极化，抑制了伤口响应基因的表达，同时诱导了水杨酸（SA）的积累和病程相关蛋白的表达。我们在此表明，壳梭孢菌素处理后伤口响应的抑制不是由SA浓度升高介导的，而可能是质膜超极化的直接作用。数据表明质膜电位在伤口和病原体防御反应的差异调节中起作用。
