Raacke Ines C, von Rad Uta, Mueller Martin J, Berger Susanne
Julius-von-Sachs-Institute for Biosciences, Pharmaceutical Biology, University of Wuerzburg, Julius-von-Sachs-Platz 2, D-97082 Wuerzburg, Germany.
Mol Plant Microbe Interact. 2006 Oct;19(10):1138-46. doi: 10.1094/MPMI-19-1138.
Cell-wall and glucopeptide components of yeast have been reported to exhibit elicitor activity. The mode of action of defense activation by yeast is not known so far. In this study, we used the model plant Arabidopsis to investigate the activation of defense responses by yeast, the effect on resistance against different pathogens, and the mode of action. Treatment of Arabidopsis plants with an autoclaved yeast suspension induced the expression of systemic acquired resistance-related genes and accumulation of the phytoalexin camalexin. Symptom development and bacterial growth after infection with a virulent strain of the pathogen Pseudomonas syringae was reduced in yeast-pretreated plants. No protection was detectable in mutants affected in the salicylate pathway, while mutants in the jasmonate or camalexin pathway were protected by yeast, indicating that the salicylate pathway is necessary for the yeast-induced resistance against P. syringae. Yeast also reduced symptom development after challenge with Botrytis cinerea. This protection was detectable in all mutants tested, indicating that it is independent of the salicylate, jasmonate, and camalexin pathway.
据报道，酵母的细胞壁和糖肽成分具有激发子活性。迄今为止，酵母激活防御的作用模式尚不清楚。在本研究中，我们使用模式植物拟南芥来研究酵母对防御反应的激活、对不同病原体抗性的影响以及作用模式。用高压灭菌的酵母悬浮液处理拟南芥植株可诱导系统获得性抗性相关基因的表达和植物抗毒素camalexin的积累。在酵母预处理的植株中，感染致病菌株丁香假单胞菌后的症状发展和细菌生长减少。在水杨酸途径受影响的突变体中未检测到保护作用，而茉莉酸或camalexin途径的突变体则受到酵母的保护，这表明水杨酸途径对于酵母诱导的对丁香假单胞菌的抗性是必需的。酵母还减少了灰葡萄孢菌侵染后的症状发展。在所有测试的突变体中都可检测到这种保护作用，表明它独立于水杨酸、茉莉酸和camalexin途径。
