利用细胞和组织培养技术研究水稻抗稻瘟病机制

Study on resistant mechanisms in rice to Magnaporthe grisea using suspension cells and calli

利用组织培养技术建立了水稻悬浮细胞和愈伤组织培养体系。用木聚糖酶激发子处理水稻悬浮细胞,引起细胞内过氧化氢和超氧阴离子含量迅速升高。木聚糖酶和稻瘟病菌提取物处理水稻悬浮细胞1 h后,编码几丁质酶的基因Cht-1表达明显增加,而编码病程相关蛋白的PR10基因没有表达,但处理12 h,后者表达明显增加。用稻瘟病菌提取物和激发子木聚糖酶处理水稻悬浮细胞,均诱导水稻细胞合成樱花素——专抗稻瘟病的抗毒素。若用它们处理水稻愈伤组织,则引起组织褐化、生长量降低、密度下降。初步结果表明:水稻悬浮细胞和愈伤组织是研究水稻抗稻瘟病机制方便、合适的实验材料。

In this study, the experimental systems of rice suspension cells and calli were established. The resistant mechanisms to Magnaporthe grisea were investigated using the systems. The results showed that the xylanase treatment induced rapid accumulation of H2 O2 and O2 in rice suspension cells. Both xylanase and the extract from M. grisea induced the expression of defense genes Cht-1 and PRIO. The expression of Cht-1 was induced obviously in suspension cells after 1 h treatment while the expression of PRIO was induced after 12 h treatment. Both xylanase and the extract from M. grisea induced the synthesis of sakuranetin, a major phytoalexin induced by blast infection. In addition, when the calli were treated with either xylanase or the extract from M. grisea, their color turned to brown, and their fresh weight and density decreased. The results indicate that suspension cells and callus are convenient and suitable plant materials for studying the mechanisms of the resistance to M. grisea in rice.