玉米大斑病菌黑色素的一些理化性质和光谱吸收特征

Characteristics and spectral analysis of melanin in Setosphaeria turcica

黑色素是某些植物和动物真菌病害的致病相关因子,不同来源的黑色素其生物合成途径可能不同。对玉米大斑病菌细胞壁结合黑色素和从培养滤液中提取的黑色素进行理化性质、紫外吸收光谱和红外光谱扫描测定,并与标准品黑色素进行比较分析,明确了玉米大斑病菌黑色素具有与标准品黑色素相似的理化性质。DHN黑色素的特异性抑制剂——三环唑,对玉米大斑病菌0号和1号小种黑色素的产生均有抑制作用;以玉米大斑病菌基因组DNA为模板,通过PCR扩增,得到了1,3,8-三羟基萘还原酶基因的同源片段,推测玉米大斑病菌黑色素合成于DHN途径。

Melanin was considered as one of the important virulence factors related to some plant and animal pathogenic fungi. Different melanins could originate from different biosynthetic pathways. The characteristics of melanin, extracted from cell wall and zymolytic filtrate of Setosphaeria turcica, were compared with standard melanin by diagnostic test, UV-Vis spectrum and infrared spectra. The results indicated that the physical and chemical characteristics of fungal melanin were similar to the standard one. Tricyclazole, a specific inhibitor of DHN melanin synthesis, could inhibit the fungal melanin＇s biosynthesis of race 1 and race 0 of S. turcica. The 1,3,8-trihydroxynaphthalene reductase gene （3HNR） was amplified by PCR with S. turcica genomic DNA as a template. All above results suggested that the melanin in S. turcica might be synthesized from DHN pathway.