【摘要】 以抗白粉病的小麦近等基因系为材料 ,研究小麦白粉菌诱导条件下 ,几丁质酶同工酶在抗白粉病的B196 9及其感病回交亲本扬麦 5号中的差异。利用Western杂交在抗、感小麦品系中都检测到 3条几丁质酶同工酶带 ,相对分子质量分别为 4 380 0 (CH1)、 2 76 0 0 (CH2 )和 184 0 0 (CH3)。这 3种几丁质酶同工酶的含量变化与小麦白粉菌侵染密切相关 ,而且在抗感品系间存在明显差异。对胞内、胞间几丁质酶提取液进行的Western杂交分析发现 ,CH1主要分布于胞内 ,CH2在胞内、胞间都有分布 ,CH3主要分布于胞间。在抗病品系中 ,CH1和CH2有较高的本底表达水平 ,且CH2和CH3在胞间积累的速度也明显快于感病品系。体外抑菌试验表明 ,经亲和层析纯化的小麦几丁质酶能酶解小麦叶片表皮细胞中已形成的白粉菌吸器更多还原

【Abstract】 The investigation of chitinase isoenzymes between near isogenic lines B1969 and Yangmai No 5 induced by the infection of Blumaria graminis(D.C.) was reported.Three isoenzymes,43 800(CH1),27 600(CH2)and 18 400(CH3),were detected by Western blot,respectively.Two of them(CH1 and CH3)showed induced expression pattern,implying its association with the resistance of wheat against powdery mildew infection.CH2 was slowly induced in susceptible wheat lines while remained stable in resistant lines.According to the Western blot patterns of either intercellular fluids or intracellular extractions of wheat leaves,it was concluded that CH1 mainly exist in intercellular spaces,CH3 in intracellular spaces and CH2 inside and outside the cells.In resistant lines,the constitutive expression of CH1 and CH2 was more strong and the accumulation of CH2 and CH3 in intercellular spaces was faster than in susceptible ones.In vitro suppression of fungal haustoria show that wheat chitinases purified by affinity chromatography could digest the fungal haustoria of powdery mildew formed in wheat epidermal cells.更多还原