番茄枯萎病菌转录因子FolMsn2的生物学功能

Biological function of transcription factor FolMsn2 in fungal plant pathogen Fusarium oxysporum f. sp. lycopersici

为探究转录因子FolMsn2在番茄枯萎病菌Fusarium oxysporum f. sp. lycopersici生长发育及致病过程中的作用,以番茄枯萎病菌野生型菌株4287为材料,利用基因敲除方法获得FolMSN2基因缺失突变体△Folmsn2及回补体菌株△Folmsn2-C,通过测定菌株的生长速率、孢子产量及致病力等表型初步分析番茄枯萎病菌中FolMSN2的生物学功能。结果显示,与野生型菌株4287相比,FolMSN2基因敲除突变体△Folmsn2生长速率显著减慢,菌株产孢量显著下降,仅为野生型菌株4287产孢量的6.7%;外界环境压力胁迫试验结果显示,FolMSN2基因缺失突变体△Folmsn2对渗透压、盐胁迫的敏感性显著提高,而对细胞壁、氧化压力胁迫变得更加耐受。此外,FolMSN2基因缺失突变体△Folmsn2对番茄苗及果实的致病力显著下降,进一步分析发现FolMSN2基因缺失影响其对玻璃纸的穿透能力;亚细胞定位结果表明,FolMsn2蛋白定位于细胞核内。表明FolMsn2参与调控番茄枯萎病菌的营养生长、无性繁殖以及对不同环境胁迫的应答过程,其可能通过影响菌丝对寄主的穿透能力来影响番茄枯萎病菌的致病力。

To determine the function of transcription factor FolMsn2 in development and pathogenesis of fungal plant pathogen Fusarium oxysporum f. sp. lycopersici, deletion mutant △ Folmsn2 was obtained from the wild type strain 4287 and the complemented strain △ Folmsn2-C was generated from mutant. Phenotypic analysis about growth rate, conidiation, and pathogenicity revealed that, compared with the wild-type strain, the FolMSN2 gene knock-out mutant displayed a significantly decrease in hyphal growth rate and a dramatic reduction in conidiation(only 6.7% of the wild type strain);external environmental stress assays found that the FolMSN2 gene knock-out mutant was more sensitive to osmotic, and salt stress but was more tolerant to cell wall and oxidative stresses. Moreover, the mutant had a significant reduction in pathogenicity and compromised penetration ability on the cellophane paper;the cellular localization of FolMsn2 revealed that FolMsn2 localized to the nuclear of F. oxysporum f. sp. lycopersici. The results indicated that FolMsn2 contributed to vegetative growth, asexual reproduction, and external environmental stress response, and might be involved in the pathogenicity of F. oxysporum f. sp.lycopersici by regulating the penetration process.