Albergoni F
Centro di Studio del Consiglio Nazionale delle Richerche sulla Biologia Cellulare e Molecolare delle piante (M.T.M.), Università di Milano (F.A.), via Celoria 26, 20133 Milano, Italy
Plant Physiol. 1998 Feb 1;116(2):681-6. doi: 10.1104/pp.116.2.681.
It was previously shown that a number of sulfhydryl [SH] group reagents (N-ethylmaleimide [NEM], iodoacetate, Ag+, HgCl2, etc.) can induce a marked, transitory stimulation of O2 uptake (QO2) in Egeria densa leaves, insensitive to CN- and salicylhydroxamic acid and inhibited by diphenylene iodonium and quinacrine. The phytotoxin fusicoccin (FC) also induces a marked increase in O2 consumption in E. densa leaves, apparently independent of the recognized stimulating action on the H+-ATPase. In this investigation we compared the FC-induced increase in O2 consumption with those induced by NEM and Ag+, and we tested for a possible interaction between FC and the two SH blockers in the activation of QO2. The results show (a) the different nature of the FC- and NEM- or Ag+-induced increases of QO2; (b) that FC counteracts the NEM- (and Ag+)-induced respiratory burst; and (c) that FC strongly reduces the damaging effects on plasma membrane permeability observed in E. densa leaves treated with the two SH reagents. Two alternative models of interpretation of the action of FC, in activating a CN--sensitive respiratory pathway and in suppressing the SH blocker-induced respiratory burst, are proposed.
先前的研究表明，许多巯基[SH]基团试剂（N - 乙基马来酰亚胺[NEM]、碘乙酸、Ag⁺、HgCl₂等）可诱导伊乐藻叶片中氧气吸收（QO₂）显著且短暂的刺激，这种刺激对氰化物和水杨羟肟酸不敏感，但受二苯撑碘鎓和奎纳克林抑制。植物毒素藤霉素（FC）也可诱导伊乐藻叶片中氧气消耗显著增加，这显然独立于其对H⁺ - ATP酶的公认刺激作用。在本研究中，我们比较了FC诱导的氧气消耗增加与NEM和Ag⁺诱导的增加，并测试了FC与两种SH阻断剂在激活QO₂过程中可能的相互作用。结果表明：（a）FC、NEM或Ag⁺诱导的QO₂增加性质不同；（b）FC可抵消NEM（和Ag⁺）诱导的呼吸爆发；（c）FC可强烈降低用两种SH试剂处理的伊乐藻叶片中观察到的对质膜通透性的损伤作用。提出了两种关于FC作用的替代解释模型，一种是激活对氰化物敏感的呼吸途径，另一种是抑制SH阻断剂诱导的呼吸爆发。
