小麦与白粉病菌互作中β-1,3-葡聚糖的细胞定位

Localization of β-1,3-glucan during interaction between wheat and barley and their powdery mildew pathogens

利用免疫胶体金方法对小麦与白粉病菌互作过程中 β 1,3 葡聚糖酶底物 ,即β 1,3 葡聚糖的合成与分布情况进行了研究。结果发现 ,白粉病菌的所有器官包括分生孢子、附着胞、入侵栓、吸器和菌丝中均未发现 β 1,3 葡聚糖存在 ;相反 ,β 1,3 葡聚糖是小麦各种细胞壁的正常组分 ,在气孔保卫细胞、纤维细胞、导管分子等的细胞壁中含量非常丰富。病原菌的侵染导致植物细胞中β 1,3 葡聚糖的合成增加 ,但在乳突结构中不含 β 1,3 葡聚糖。以上结果说明 ,往小麦中导入外源 β 1,3 葡聚糖酶基因并高效表达 ,不会对病原菌结构产生直接的破坏和抑制作用 ;相反 。

The synthesis and distribution patterns of β 1,3 glucan during the interaction between wheat and its powdery mildew pathogen were examined with cytochemical method. The results showed that there was no β 1,3 glucan located in any parts of the pathogen, such as conidia, appressoria, penetration pegs, haustoria, and hyphae. In contrast, β 1,3 glucan was found in the host cell walls, especially to be abundant in guard cells of stomas, fibre cells, vessel elements, and epidermal hairs. The pathogen infection could result in the accumulation of β 1,3 glucan in the plant cell walls but not in the papilla formed at the penetration sites. These contradicted the assumption that over expression of β 1,3 glucanase genes in transgenic wheat could enhance plant resistance against powdery mildew by directly digesting the fungal haustoria and hyphae. Instead, it can be supposed that the unsuitable expression would disturb the normal development of plants.