Liu Lu, Huang Yinghua, Song Handa, Luo Mei, Dong Zhangyong
Innovative Institute for Plant Health/Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
Guangdong Agribusiness Tropical Crop Science Institute, Maoming 525100, China.
J Fungi (Basel). 2023 Mar 16;9(3):365. doi: 10.3390/jof9030365.
f. sp. (), which causes Fusarium wilt of bananas, is considered one of the most destructive fungal pathogens of banana crops worldwide. During infection, secretes many different proteins which promote its colonization of plant tissues. Although has no sexual cycle, it has been reported to secrete an α-pheromone, which acts as a growth regulator, chemoattractant, and quorum-sensing signaling molecule; and to encode a putative protein with the hallmarks of fungal α-pheromone precursors. In this study, we identified an ortholog of the α-pheromone precursor gene, , in tropical race 4 (TR4), and showed that it was necessary for the growth and virulence of TR4. deletion from the TR4 genome resulted in decreased fungal growth, increased sensitivity to oxidative stress and cell-wall-damaging agents, and attenuation of pathogen virulence towards banana plantlets. Subcellular localization analysis revealed that Foc4-PP1 was concentrated in the nuclei and cytoplasm of cells, where it could suppress BAX-induced programmed cell death. In conclusion, these findings suggest that Foc4-PP1 contributes to TR4 virulence by promoting hyphal growth and abiotic stress resistance and inhibiting the immune defense responses of host plants.
尖孢镰刀菌古巴专化型（Fusarium oxysporum f. sp. cubense），可引发香蕉枯萎病，被认为是全球香蕉作物中最具破坏性的真菌病原体之一。在侵染过程中，它会分泌许多不同的蛋白质，以促进其在植物组织中的定殖。尽管它没有有性生殖周期，但据报道它会分泌一种α-信息素，该信息素可作为生长调节剂、化学引诱剂和群体感应信号分子；并且编码一种具有真菌α-信息素前体特征的假定蛋白。在本研究中，我们在尖孢镰刀菌古巴专化型热带4号小种（Foc tropical race 4，TR4）中鉴定出α-信息素前体基因Foc4-PP1的一个直系同源基因，并表明它对TR4的生长和毒力是必需的。从TR4基因组中缺失该基因导致真菌生长减缓，对氧化应激和细胞壁损伤剂的敏感性增加，以及病原体对香蕉幼苗的毒力减弱。亚细胞定位分析表明，Foc4-PP1集中在TR4细胞的细胞核和细胞质中，在那里它可以抑制BAX诱导的程序性细胞死亡。总之，这些发现表明Foc4-PP1通过促进菌丝生长和抗非生物胁迫以及抑制宿主植物的免疫防御反应，对TR4的毒力起作用。
