局部力学刺激对黄瓜系统抗病性的诱导

病原真菌在侵入植物细胞过程中,除了分泌化学物质外还通过物理挤压细胞产生力学作用.用压应力作为力学信号,研究了局部力学刺激对黄瓜系统抗病性的诱导.结果表明,力学刺激可以诱导黄瓜系统抗病性的产生.当细胞壁与质膜间的黏附被Arg-Gly-Asp(RGD)阻断后,力学刺激对黄瓜系统抗病性的诱导几乎完全被减除.通过薄层色谱和液相色谱分析,发现力学刺激可以使植保素含量明显增加.这表明黄瓜植保素的积累可能是力学刺激诱导其产生抗性的原因之一.而细胞壁与质膜间的黏附被RGD阻断后,力学刺激只能诱导植保素的部分积累.即力学刺激对植保素积累的诱导依赖于细胞膜与细胞壁间的黏附.

Disease Resistance of Cucumber Induced by Local Mechanical Stimulation

During the process of pathogens penetrating the plant cell, pathogens often secret some chemicals into plant cells, at the same time, they also produce mechanical signal by physical pressure on the plant cell. Here the pressure is used as the stress signal, to study its effect on phytoalexin accumulation and the induction of plant resistance in cucumber seedling. It is found that stress can induce the resistance in cucumber seedling significantly. When breaking the plant cell wall and plasma membrane adhesion by RGD peptides, the resistance induction is almost eliminated. Results from TLC and HPLC showed that stress stimulation could increase phytoalexin accumulation in cucumber seedling. This suggests that the accumulation of phytoalexin is one possible reason of the increased resistance after stress stimulation. When the adhesion between plant cell wall and plasma membrane was block by RGD, there is only small amount of phytoalexin accumulation compared with the control, suggesting that the stress induced phytoalexin accumulation and resistance is relying on the adhesion of plant cell wall and plasma membrane.