Hadwiger L A, Chang M M, Parsons M A
Department of Plant Pathology, Washington State University, Pullman 99164, USA.
Mol Plant Microbe Interact. 1995 Nov-Dec;8(6):871-9. doi: 10.1094/mpmi-8-0871.
The inoculation of pea endocarp tissue with the bean pathogen Fusarium solani f. sp. phaseoli results in a non-host resistance response causing a complete cessation of fungal growth within 6 to 8 h. In addition to previously reported elicitation by chitosan, we now report that components of this response are also induced by a DNase released from this fungus. A single band of protein corresponding with DNase activity elicits phytoalexin production and the accumulation of RnA homologous with the pathogenesis-related (PR) genes DRR49, DRR206, and DRR230. Both the enzyme activity and the eliciting potential of the Fusarium DNase (Fsp DNase) are heat stable but susceptible to digestion by proteinase K. Fsp DNase mimics the intact fungus in inducing resistance against F. solani f. sp. pisi. Also, Fsp DNase causes similar cytologically detectable changes in pea tissue, such as increasing hypersensitive discoloration and diminishing fluorescence of Hoechst 33342-stained nuclei and fluorescein diacetate stained cells.
用菜豆病原体菜豆尖镰孢菌接种豌豆内果皮组织会引发非寄主抗性反应，导致真菌生长在6至8小时内完全停止。除了先前报道的壳聚糖诱导作用外，我们现在报告，这种反应的成分也可由该真菌释放的一种脱氧核糖核酸酶（DNase）诱导。与DNase活性相对应的一条蛋白质带可引发植物抗毒素的产生以及与病程相关（PR）基因DRR49、DRR206和DRR230同源的RNA的积累。镰刀菌DNase（Fsp DNase）的酶活性和诱导潜力均对热稳定，但易被蛋白酶K消化。Fsp DNase在诱导对豌豆尖镰孢菌的抗性方面可模拟完整真菌。此外，Fsp DNase在豌豆组织中会引起类似的细胞学可检测变化，如过敏变色增加以及经Hoechst 33342染色的细胞核和经荧光素二乙酸酯染色的细胞的荧光减弱。
