Abstract

Indole-3-acetic acid (IAA) is a molecule with the chemical formula C₁₀H₉NO₂, with a demonstrated presence in various environments and organisms, and with a biological function in several of these organisms, most notably in plants where it acts as a growth hormone. The existence of microorganisms with the ability to catabolize or assimilate IAA has long been recognized. To date, two sets of gene clusters underlying this property in bacteria have been identified and characterized: one (iac) is responsible for the aerobic degradation of IAA into catechol, and another (iaa) for the anaerobic conversion of IAA to 2-aminobenzoyl-CoA. Here, we summarize the literature on the products, reactions, and pathways that these gene clusters encode. We explore two hypotheses about the benefit that iac/iaa gene clusters confer upon their bacterial hosts: (1) exploitation of IAA as a source of carbon, nitrogen, and energy; and (2) interference with IAA-dependent processes and functions in other organisms, including plants. The evidence for both hypotheses will be reviewed for iac/iaa-carrying model strains of Pseudomonas putida, Enterobacter soli, Acinetobacter baumannii, Paraburkholderia phytofirmans, Caballeronia glathei, Aromatoleum evansii, and Aromatoleum aromaticum, more specifically in the context of access to IAA in the environments from which these bacteria were originally isolated, which include not only plants, but also soils and sediment, as well as patients in hospital environments. We end the mini-review with an outlook for iac/iaa-inspired research that addresses current gaps in knowledge, biotechnological applications of iac/iaa-encoded enzymology, and the use of IAA-destroying bacteria to treat pathologies related to IAA excess in plants and humans.

Key points

• The iac/iaa gene clusters encode bacterial catabolism of the plant growth hormone IAA.

• Plants are not the only environment where IAA or IAA-degrading bacteria can be found.

• The iac/iaa genes allow growth at the expense of IAA; other benefits remain unknown.

中文翻译：

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吲哚-3-乙酸的细菌分解代谢

摘要

吲哚-3-乙酸（IAA）是化学分子式为C ₁₀ H ₉ NO ₂的分子，在各种环境和生物中均表现出存在，并在其中一些生物中具有生物学功能，尤其是在其中充当生长激素。长期以来，人们已经认识到具有能够分解或吸收IAA的微生物。迄今为止，已经鉴定了两组基因簇中的细菌这个属性的底层和表征：一个（IAC）负责IAA的需氧降解成儿茶酚，和另一个（IAA）将IAA厌氧转化为2-氨基苯甲酰辅酶A。在这里，我们总结了有关这些基因簇编码的产物，反应和途径的文献。我们探讨了有关iac / iaa基因簇对细菌宿主有益的两个假设：（1）利用IAA作为碳，氮和能量的来源；（2）干扰其他植物（包括植物）中依赖IAA的过程和功能。两种假说证据将用于审查IAC / IAA -carrying的模式菌株恶臭假单胞菌，肠杆菌属索利，鲍曼不动杆菌，Paraburkholderia phytofirmans，Caballeronia glathei，Aromatoleum evansii和Aromatoleumaromaticum，更具体地说，是在最初分离出这些细菌的环境中获得IAA的情况下，这些环境不仅包括植物，还包括土壤和沉积物，以及医院环境中的患者。我们以对Iac / iaa启发的研究的前景作为结尾进行了微型评论，该研究致力于解决当前知识，IAC / iaa编码酶学的生物技术应用以及利用IAA破坏细菌来治疗植物中与IAA过量相关的病理学方面的空白。和人类。

关键点

•的IAC / IAA基因簇编码的植物生长激素IAA的细菌分解代谢。

•植物不是唯一可以发现IAA或IAA降解细菌的环境。

•在IAC / IAA基因允许在IAA的费用增长; 其他好处仍然未知。