Indole-3-acetic acid (IAA) plays an important role in the growth and development of plants. In this study, a series of predominant strains were isolated and identified as Enterobacter sp. with remarkable IAA-producing capabilities. The IAA-producing strains are mainly tryptophan-dependent and have significantly high yields of IAA (3477 μg mL⁻¹ and 3378 μg mL⁻¹). The ipdC gene encoding indole-3-pyruvate decarboxylase was identified by genomic analysis and RT-qPCR analysis, indicating the involvement of the indole-3-pyruvic acid (IPyA) pathway of IAA biosynthesis. The IPyA pathway was also confirmed by the intermediate assay. The IAA product of microbial metabolites was isolated, purified and characterized. These microbes exhibiting IAA production significantly promoted the growth of maize, increasing root length, plant height, fresh weight and dry weight. Thus, Enterobacter sp. with high IAA production has great prospects in agricultural and industrial applications.

中文翻译：

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植物促生肠杆菌中吲哚-3-乙酸的表征与合成

吲哚-3-乙酸（IAA）在植物的生长发育中发挥着重要作用。在这项研究中，一系列优势菌株被分离并鉴定为肠杆菌属。具有卓越的 IAA 生产能力。产生IAA的菌株主要依赖色氨酸并且具有显着高的IAA产量（3477 μg mL ^-1和3378 μg mL ^-1）。知识产权署通过基因组分析和RT-qPCR分析鉴定了编码吲哚-3-丙酮酸脱羧酶的基因，表明吲哚-3-丙酮酸（IPyA）途径参与了IAA的生物合成。IPyA途径也被中间测定证实。微生物代谢物的 IAA 产物被分离、纯化和表征。这些表现出 IAA 产生的微生物显着促进了玉米的生长，增加了根长、株高、鲜重和干重。因此，肠杆菌属。IAA产量高，在农业和工业应用方面前景广阔。