GFP标记的尖孢镰刀菌西瓜专化型侵染西瓜过程观察

Observation of the Infection Process of Watermelon by Fusarium oxysporum f.sp. niveum Using the GFP Marker

将绿色荧光蛋白基因转入西瓜尖孢镰刀菌FON中,并利用荧光共聚焦显微镜观察GFP标记菌株侵染西瓜的过程。结果显示,转化子连续转接4代能够稳定遗传,荧光强度良好,PCR验证gfp基因已转入菌株FON中;利用GFP标记菌株在荧光共聚焦显微镜下观察其侵染西瓜苗的过程,发现在1/2 MS培养的西瓜苗中,FON经过48 h侵染即可进入西瓜的根维管束,第3天便进入茎维管束,第4天进入叶维管束(包括叶柄和叶脉);在土壤盆栽条件下,侵染后2 d FON进入西瓜的根维管束,第9天进入茎维管束,第11天进入叶维管束。培养基培养与土壤盆栽相比,培养基栽培FON侵染的速度更快。

Fusarium oxysporum f. sp. Niveum（FON）was successfully transformed with the gene coding for green fluorescent protein （GFP）. Transformants could emit quite stable fluorescence under 488 nm laser after four successive subcultures. PCR analysis confirmed that the gfp gene was transformed into FON. Observation of watermelon infection process by the GFP expressing FON strain was then carried out. Watermelon grown on 1/2 MS medium and soil were used for the study and their roots were inoculated with the FON strain. Results revealed that FON invaded into roots, pseudostem, and leaf vascular bundle after 48 hours, 3 days and 4 days, respectively, when the seedlings grown on the 1/2 MS medium were inoculated. On the soil-grown seedlings, FON was detected in roots, pseudostem and leaf vascular bundle after 2, 9 and 11 days, respectively. The infection of FON invading watermelon grown on the 1/2 MS medium is faster than in pots.