Esteyawermicola已显示出有望成为对抗松树枯萎病的有效生物防治剂,松木线虫(PWN,松材线虫)。然而,E.vermicola之间的体内相互作用,PWN,松树寄主不太了解,在人口和分子水平。在这项研究中,我们进行了一系列生物测定,以研究松树木质部中的E.wermicola定植模式及其对健康和PWN诱导的枯萎树木中PWN入侵的种群反应。我们的结果表明,尽管E.vermicola表现出缓慢的生长,它的分生孢子发芽并沿着松树管胞生长,甚至产生能够在木质部内引发PWN感染的月状分生孢子。有趣的是,虽然接种后松树木质部无法检测到真菌菌丝,由于PWN的入侵,Vermicola种群立即增加。此外,我们在PWN诱导的枯萎松中观察到真菌定植的“越蛙”扩散模式,由真菌感染的线虫的迁移促进。此外,我们使用转录组学分析探索了真菌耐受松树防御系统的分子机制。比较转录组学表明,碳水化合物代谢和非生物胁迫诱导的氧化还原活性参与了对松树防御化合物β-pine烯的真菌耐受性。这项研究增强了我们对E.vermicola如何在松树木质部中定植并持续存在的理解,它对植物防御化合物的分子反应,以及PWN入侵后的种群动态,验证其作为松树枯萎病生物防治剂的功效。
Esteya vermicola has shown promise as an efficient biological control agent against pine wilt disease, a devastating disease in pine forests caused by the pinewood nematode (PWN, Bursaphelenchus xylophilus). However, the in vivo interactions among E. vermicola, PWN, and pine hosts are less understood, both at the population and molecular levels. In this study, we performed a series of bioassays to investigate E. vermicola colonization patterns in pine
xylem and its population responses to PWN invasion in healthy and PWN-induced wilting trees. Our results demonstrated that although E. vermicola exhibits slow growth, its conidia germinate and grew along the pine tracheid, even producing lunate conidia capable of initiating PWN infections within the
xylem. Interestingly, while fungal hyphae became undetectable in pine sapling
xylem after inoculation, the E. vermicola population increased immediately in response to PWN invasion. Furthermore, we observed a \"leap-frog\" dispersal pattern of fungal colonization in PWN-induced wilting pines, facilitated by the migration of fungal-infected nematodes. Moreover, we explored the molecular mechanisms underlying fungal tolerance to pine defense systems using transcriptomic analysis. Comparative transcriptomics revealed that carbohydrate metabolism and abiotic stress-induced oxidoreductive activities are involved in the fungal tolerance to the pine defense compound β-pinene. This study enhances our understanding of how E. vermicola colonizes and persists within pine
xylem, its molecular responses to plant defense compounds, and its population dynamics upon PWN invasion, validating its efficacy as a biocontrol agent against pine wilt disease.