Endofungal bacteria are bacterial symbionts of fungi that exist within fungal hyphae and spores. There is increasing evidence that these bacteria, alone or in combination with their fungal hosts play a critical role in tripartite symbioses with plants, where they may contribute to plant growth and disease resistance to microbial pathogens. As the frequency of bacteria in fungi is commonly very low, breakthroughs in technology such as molecular taxonomy and laser scanning microscopy were required to establish the functional contribution of these bacteria in complex symbioses. Yet, the overall biological significance of endofungal bacteria is largely unknown and further progress in understanding is hampered by a very few biological systems where endofungal bacteria have been described mechanistically. We review here the current knowledge on endobacteria (EB) and their role in different types of fungal symbioses with plants. We show that various attempts to cure fungal cells from endobacteria failed, further suggesting that they play a crucial role in the symbiosis. Moreover, isolation of some of the endobacteria from their fungal hosts allowed confirming their autonomous beneficial activity such as plant growth promotion and resistance-inducing activity. The review addresses the potential agricultural significance of endofungal bacteria and their role in supporting sustainable agriculture by promoting plant growth, improving plant resistance, and decreasing yield loss caused by many microbial pathogens.

中文翻译：

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Endofungal Bacteria 增加宿主真菌的适应性并影响它们与农作物的关联。

内真菌细菌是真菌的细菌共生体，存在于真菌菌丝和孢子中。越来越多的证据表明，这些细菌单独或与它们的真菌宿主结合在与植物的三方共生中发挥关键作用，它们可能有助于植物生长和对微生物病原体的抗病性。由于真菌中细菌的频率通常非常低，因此需要分子分类学和激光扫描显微镜等技术的突破来确定这些细菌在复杂共生体中的功能贡献。然而，内真菌细菌的整体生物学意义在很大程度上是未知的，并且在理解方面的进一步进展受到极少数生物系统的阻碍，其中内真菌细菌已被机械描述。我们在这里回顾了目前关于内生菌 (EB) 的知识及其在不同类型的真菌与植物共生中的作用。我们表明，从内细菌中治愈真菌细胞的各种尝试都失败了，进一步表明它们在共生中起着至关重要的作用。此外，从它们的真菌宿主中分离出一些内生菌可以确认它们的自主有益活性，例如植物生长促进和抗性诱导活性。该综述探讨了内生真菌细菌的潜在农业意义及其通过促进植物生长、提高植物抗性和减少由许多微生物病原体引起的产量损失来支持可持续农业的作用。我们表明，从内细菌中治愈真菌细胞的各种尝试都失败了，进一步表明它们在共生中起着至关重要的作用。此外，从它们的真菌宿主中分离出一些内生菌可以确认它们的自主有益活性，例如植物生长促进和抗性诱导活性。该综述探讨了内生真菌细菌的潜在农业意义及其通过促进植物生长、提高植物抗性和减少由许多微生物病原体引起的产量损失来支持可持续农业的作用。我们表明，从内细菌中治愈真菌细胞的各种尝试都失败了，进一步表明它们在共生中起着至关重要的作用。此外，从它们的真菌宿主中分离出一些内生菌可以确认它们的自主有益活性，例如植物生长促进和抗性诱导活性。该综述探讨了内生真菌细菌的潜在农业意义及其通过促进植物生长、提高植物抗性和减少由许多微生物病原体引起的产量损失来支持可持续农业的作用。