Song Tiantian, Li Chan, Jin Kai, Xia Yuxian
Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China.
Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China.
J Fungi (Basel). 2024 Aug 2;10(8):544. doi: 10.3390/jof10080544.
Insect pathogenic fungi have shown great potential in agricultural pest control. Conidiation is crucial for the survival of filamentous fungi, and dispersal occurs through two methods: normal conidiation, where conidia differentiate from mycelium, and microcycle conidiation, which involves conidial budding. The conidiation process is related to cell separation. The forkhead box gene in plays a crucial role in cell separation. Nevertheless, the function of Sep1 has not been clarified in filamentous fungi. Here, MaSep1, the homolog of Sep1 in , was identified and subjected to functional analysis. The findings revealed that conidial germination of the -deletion strain (Δ) was accelerated and the time for 50% germination rate of conidial was shortened by 1 h, while the conidial production of Δ was considerably reduced. The resistances to heat shock and UV-B irradiation of Δ were enhanced, and the expression of some genes involved in DNA damage repair and heat shock response was significantly increased in Δ. The disruption of had no effect on the virulence of . Interestingly, Δ conducted the normal conidiation on the microcycle conidiation medium, SYA. Furthermore, 127 DEGs were identified by RNA-Seq between the wild-type and Δ strains during microcycle conidiation, proving that MaSep1 mediated the conidiation pattern shift by governing some genes associated with conidiation, cell division, and cell wall formation.
昆虫病原真菌在农业害虫防治中已显示出巨大潜力。分生孢子形成对于丝状真菌的存活至关重要，其传播通过两种方式进行：正常分生孢子形成，即分生孢子从菌丝体分化而来；以及微循环分生孢子形成，涉及分生孢子出芽。分生孢子形成过程与细胞分离有关。叉头框基因在细胞分离中起关键作用。然而，Sep1在丝状真菌中的功能尚未阐明。在此，鉴定了MaSep1，即中的Sep1同源物，并对其进行了功能分析。研究结果表明，缺失菌株（Δ）的分生孢子萌发加速，分生孢子50%萌发率的时间缩短了1小时，而Δ的分生孢子产量显著降低。Δ对热休克和UV-B辐射的抗性增强，并且在Δ中一些参与DNA损伤修复和热休克反应的基因表达显著增加。的破坏对的毒力没有影响。有趣的是，Δ在微循环分生孢子形成培养基SYA上进行正常的分生孢子形成。此外，在微循环分生孢子形成过程中，通过RNA-Seq在野生型和Δ菌株之间鉴定出127个差异表达基因（DEG），证明MaSep1通过调控一些与分生孢子形成、细胞分裂和细胞壁形成相关的基因介导了分生孢子形成模式的转变。
