Mechanisms of toxicity of anti-insect proteins from latex of mulberry trees known as a host plant of silkworms.

将编码桑树抗虫蛋白的mlx56基因导入拟南芥，以阐明mlx基因应用的可能性。在叶片中观察到mlx56基因在转录水平上的表达，但免疫印迹分析未检测到mlx56蛋白的表达，且对家蚕幼虫和甘蓝蛾无毒害作用。MLX56与家蚕幼虫周围膜的整个部分结合，而对家蚕幼虫几乎没有结合。结果表明，MLX56的靶标部位是围食膜，家蚕幼虫通过与MLX56形成低亲和力的围围膜来绕开MLX56。

A mlx56 gene encoding mulberry anti-insect protein was introduced into Arabidopsis thaliana in order to elucidate the possibility of application use of a mlx gene. The expression of mlx56 gene in leaves was observed at a transcription level, however, the MLX56 protein could not be detected by immunoblot analysis, and no toxicity was observed against larvae of the Eri-silkworms and the cabbage moth. The MLX56 bind at entire part of peritrophic membrane of larvae of the Eri-silkworm whereas little binding property was observed against that of larvae of the silkworm. The results strongly suggested that the target site of the MLX56 is the peritrophic membrane, and larvae of the silkworm circumvent from the MLX56 by developing low-affinity peritrophic membrane with the MLX56.