Cyclic di-AMP Acts as an Extracellular Signal That Impacts Bacillus subtilis Biofilm Formation and Plant Attachment.
Cyclic di-AMP Acts as an Extracellular Signal That Impacts Bacillus subtilis Biofilm Formation and Plant Attachment.
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DOI：
10.1128/mbio.00341-18
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发表时间：
2018-03-27
期刊：
影响因子：
6.4
通讯作者：
Shank EA
中科院分区：
文献类型：
--
作者：
Townsley L;Yannarell SM;Huynh TN;Woodward JJ;Shank EA
人们越来越重视细菌对高等生物的影响。植物根部通常含有有益的微生物，如革兰氏阳性根际细菌枯草芽孢杆菌，影响它们的生长和对疾病的易感性。形成被称为生物膜的表面附着微生物群落的能力对于B. subtilis粘附和保护植物根部的能力至关重要。在这项研究中，检测了已知合成和降解第二信使环二腺苷酸单磷酸（c-di-AMP）的B. subtilis基因缺失的菌株参与生物膜形成和植物附着。我们发现c-di-AMP的细胞内产生影响菌落生物膜结构、生物膜基因表达和B. subtilis中的植物附着。我们还表明，B. subtilis分泌c-di-AMP和推定的c-di-AMP转运蛋白影响生物膜的形成和植物根定殖。综上所述，我们的数据描述了一个新的作用，c-di-AMP作为一种化学信号，影响重要的细胞过程中的环境和农业重要的土壤细菌B。这些结果表明，“细胞内”信号分子c-di-AMP也可能在植物微生物组内的细菌间细胞间通讯中发挥以前未被认识到的作用。植物根部的细菌群落可以显著影响其生长和病原体抗性。然而，在大多数情况下，介导这些群落中宿主-微生物和微生物-微生物相互作用的信号是未知的。对这些相互作用机制的详细了解有助于为农业或环境目的操纵这些社区。枯草芽孢杆菌是一种促进植物生长的细菌，通过形成生物膜粘附在根部。因此，我们开始探索可能影响其生物膜形成的信号。我们发现，B. subtilis分泌c-di-AMP，并且产生、降解或转运环二腺苷酸单磷酸（c-di-AMP;一种常见的细菌第二信使）的能力影响B. subtilis生物膜基因表达和植物附着。据我们所知，这是c-di-AMP影响互利宿主-微生物关联的第一个证明，并表明c-di-AMP可能作为以前未被认识到的细胞外信号发挥作用，能够介导植物微生物组内的相互作用。
There is a growing appreciation for the impact that bacteria have on higher organisms. Plant roots often harbor beneficial microbes, such as the Gram-positive rhizobacterium Bacillus subtilis, that influence their growth and susceptibility to disease. The ability to form surface-attached microbial communities called biofilms is crucial for the ability of B. subtilis to adhere to and protect plant roots. In this study, strains harboring deletions of the B. subtilis genes known to synthesize and degrade the second messenger cyclic di-adenylate monophosphate (c-di-AMP) were examined for their involvement in biofilm formation and plant attachment. We found that intracellular production of c-di-AMP impacts colony biofilm architecture, biofilm gene expression, and plant attachment in B. subtilis. We also show that B. subtilis secretes c-di-AMP and that putative c-di-AMP transporters impact biofilm formation and plant root colonization. Taken together, our data describe a new role for c-di-AMP as a chemical signal that affects important cellular processes in the environmentally and agriculturally important soil bacterium B. subtilis. These results suggest that the “intracellular” signaling molecule c-di-AMP may also play a previously unappreciated role in interbacterial cell-cell communication within plant microbiomes. Plants harbor bacterial communities on their roots that can significantly impact their growth and pathogen resistance. In most cases, however, the signals that mediate host-microbe and microbe-microbe interactions within these communities are unknown. A detailed understanding of these interaction mechanisms could facilitate the manipulation of these communities for agricultural or environmental purposes. Bacillus subtilis is a plant-growth-promoting bacterium that adheres to roots by forming biofilms. We therefore began by exploring signals that might impact its biofilm formation. We found that B. subtilis secretes c-di-AMP and that the ability to produce, degrade, or transport cyclic di-adenylate monophosphate (c-di-AMP; a common bacterial second messenger) affects B. subtilis biofilm gene expression and plant attachment. To our knowledge, this is the first demonstration of c-di-AMP impacting a mutualist host-microbe association and suggests that c-di-AMP may function as a previously unappreciated extracellular signal able to mediate interactions within plant microbiomes.