Indole acetic acid overproduction transformants of the rhizobacterium Pseudomonas sp. UW4

• Published in: Antonie van Leeuwenhoek Vol. 111; no. 9; pp. 1645 - 1660
• Main Authors: Duca, Daiana R., Rose, David R., Glick, Bernard R.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.09.2018; Springer Nature B.V
• Subjects: 1-Aminocyclopropane-1-carboxylate deaminase; Acetic acid; Acids; aseptic conditions; Bacteria; Biomedical and Life Sciences; Biosynthesis; canola; Elongation; enzyme activity; Gene expression; gene overexpression; Genes; genetic vectors; Gnotobiotic; Growth rate; indole acetic acid; Indoleacetic acid; Life Sciences; Medical Microbiology; Microbiology; Original Paper; Plant growth; plant growth-promoting rhizobacteria; Plant hormones; Plant Sciences; Polymerase chain reaction; Pseudomonas; quantitative polymerase chain reaction; Rhizobium; root growth; Soil Science & Conservation; Plant-growth-promoting bacteria; Rhizobacteria; Bacterial transformants; Indoleacetic acid biosynthesis; ACC deaminase
• ISSN: 0003-6072; 1572-9699; 1572-9699
• DOI: 10.1007/s10482-018-1051-7

The plant growth-promoting rhizobacterium Pseudomonas sp. UW4 was transformed to increase the biosynthesis of the auxin, indole-3-acetic acid (IAA). Four native IAA biosynthesis genes from strain UW4 were individually cloned into an expression vector and introduced back into the wild-type strain. Quantitative real-time polymerase chain reaction analysis revealed that the introduced genes ami, nit, nthAB and phe were all overexpressed in these transformants. A significant increase in the production of IAA was observed for all modified strains. Canola plants inoculated with the modified strains showed enhanced root elongation under gnotobiotic conditions. The growth rate and 1-aminocyclopropane-1-carboxylate deaminase activity of transformant strains was lower compared to the wild-type. The indoleacetic acid biosynthesis pathways and the role of this phytohormone in the mechanism of plant growth stimulation by Pseudomonas sp. UW4 is discussed.