极端低温对稻瘟菌的筛选及其生化机制初探

 本研究利用来自我国南北稻区田间稻瘟菌菌株，对其进行了低温耐受性比较和统计分析。结果表明，南方与东北田间稻瘟菌在低温耐受性上存在明显差异：95%东北菌株可以忍受至少一周的-15℃低温处理，而相同条件下南方菌株仅有65%菌株存活。模拟东北冬季田间生境，选取10株低温敏感型菌株进行临界致死低温条件下的继代处理，发现-15℃条件下反复冻融处理55次后，其中8株低温耐受水平得到显著提高，且部分菌株的培养性状和抗药性相继发生改变。在此基础上，对抗性增强菌株的非原生质体蛋白进行双向电泳和差异蛋白质质谱分析，获得了响应低温的分泌蛋白及其指纹信息。本研究为进一步探索温度等环境因子对稻瘟菌的致变作用奠定了基础。

Effects of extreme low temperature on the biological and biochemical activities of Magnaporthe oryzae

Tolerance comparisons to low temperature were performed between different strains of blast fungi isolated from rice fields of Northern and Southern China.Statistical analysis indicated that there existed a remarkable difference in low temperature tolerance between northern and southern isolates.More than 95% strains from northeastern area can tolerate low temperature of-15℃ at least for one week.However,only 65% strains from Southern China can survive.Based on this,several strains sensitive to low temperature were selected and subjected to the critical lethal low temperature for successive generations.The results showed that low-temperature tolerability of eight strains were significantly improved through 55 cycles of repeated freeze-thaw treatment.Culture characteristics and resistance to antifungal chemicals of some strains were also changed.Eleven secretory proteins from the enhanced tolerant strains were identified by two dimensional gel electrophoresis and mass spectrometry analysis.This study provides important information for effective strategy in the prevention and control of rice fungal blast.