The number of sustainable agriculture techniques to improve pest management and environmental safety is rising, as biological control agents are used to enhance disease resistance and abiotic stress tolerance in crops. Here, we investigated the capacity of the Photorhabdus luminescens secondary variant to react to plant root exudates and their behavior toward microorganisms in the rhizosphere. P. luminescens is known to live in symbiosis with entomopathogenic nematodes (EPNs) and to be highly pathogenic toward insects. The P. luminescens-EPN relationship has been widely studied, and this combination has been used as a biological control agent; however, not much attention has been paid to the putative lifestyle of P. luminescens in the rhizosphere. We performed transcriptome analysis to show how P. luminescens responds to plant root exudates. The analysis highlighted genes involved in chitin degradation, biofilm regulation, formation of flagella, and type VI secretion system. Furthermore, we provide evidence that P. luminescens can inhibit growth of phytopathogenic fungi. Finally, we demonstrated a specific interaction of P. luminescens with plant roots. Understanding the role and the function of this bacterium in the rhizosphere might accelerate the progress in biocontrol manipulation and elucidate the peculiar mechanisms adopted by plant growth-promoting rhizobacteria in plant root interactions.

中文翻译：

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生物防治剂和昆虫病原体光致发光菌与植物根部相互作用。

随着生物防治剂被用于增强农作物的抗病性和非生物胁迫耐受性，用于改善害虫管理和环境安全的可持续农业技术的数量正在增加。在这里，我们调查了Photorhabdus luminescens次级变种与植物根系分泌物反应的能力及其对根际微生物的行为。P. luminescens已知住在与线虫（个EPN）共生和是对昆虫的高致病性。的P. luminescens -EPN关系已被广泛研究，并且这种组合已被用作生物控制剂; 然而，人们对P. luminescens的假定生活方式没有给予太多关注。在根际。我们进行了转录组分析，以显示P. luminescens如何响应植物根系分泌物。分析重点介绍了几丁质降解，生物膜调节，鞭毛形成和VI型分泌系统所涉及的基因。此外，我们提供的证据表明，P。luminescens可以抑制植物致病真菌的生长。最后，我们证明了发光假单胞菌与植物根的特定相互作用。了解这种细菌在根际中的作用和功能可能会加速生物控制操作的进展，并阐明植物生长促进根际细菌在植物根系相互作用中采用的独特机制。