Nürnberger T, Colling C, Hahlbrock K, Jabs T, Renelt A, Sacks W R, Scheel D
Max-Planck-Institut für Züchtungsforschung, Abteilung Biochemie, Carl-von-Linné-Weg, Köln, Germany.
Biochem Soc Symp. 1994;60:173-82.
Treatment of cultured parsley cells or protoplasts with a purified extracellular glycoprotein from Phytophthora megasperma f.sp. glycinea induces the transcription of the same set of defence-related genes as is activated in parsley leaves upon infection. Elicitor activity was shown to reside in a specific portion of the protein moiety which was isolated, sequenced and synthesized. Partial cDNAs encoding the entire mature protein as well as other related proteins have been isolated, indicating the presence of a small gene family. The elicitor-active oligopeptide is located in the C-terminal portion of the deduced amino acid sequence. Binding of the elicitor to target sites on the parsley plasma membrane appears to be the initial event in defence gene activation. The subsequent intracellular transduction of the elicitor signal was shown to involve rapid and transient influxes of Ca2+ and H+, as well as effluxes of K+ and Cl-. Inhibition of elicitor-induced ion fluxes by channel blockers also inhibited phytoalexin synthesis, while stimulation of similar ion fluxes by treatment of cells or protoplasts with the polyene antibiotic, amphotericin B, induced the production of phytoalexins and activated the complete set of defence-related genes in the absence of elicitor.
用来自大豆疫霉大豆专化型的纯化细胞外糖蛋白处理培养的欧芹细胞或原生质体，可诱导一系列与防御相关的基因转录，这些基因在欧芹叶片受感染时也会被激活。诱导活性被证明存在于蛋白质部分的一个特定区域，该区域已被分离、测序并合成。已分离出编码整个成熟蛋白以及其他相关蛋白的部分cDNA，表明存在一个小基因家族。具有诱导活性的寡肽位于推导氨基酸序列的C末端部分。诱导物与欧芹质膜上靶位点的结合似乎是防御基因激活的初始事件。随后诱导物信号的细胞内转导显示涉及Ca2+和H+的快速短暂内流以及K+和Cl-的外流。通道阻滞剂对诱导物诱导的离子通量的抑制也抑制了植保素的合成，而用多烯抗生素两性霉素B处理细胞或原生质体刺激类似的离子通量，则在没有诱导物的情况下诱导了植保素的产生并激活了整套与防御相关的基因。
