We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
INDOLE-3-ACETIC ACID (IAA) PRODUCTION IN METAL-TOLERANT BACTERIAL ISOLATES FROM THE SERPENTINE OUTCROPS OF EASTERN BOSNIA.
- Authors
Anesa, Ahatović Hajro; Mujo, Hasanović; Adaleta, Durmić-Pašić
- Abstract
Plant growth-promoting bacteria (PGPR) colonize the rhizosphere and improve plant growth through different mechanisms. Production of indole-3-acetic acid (IAA), one of the most physiologically active auxins, is an essential tool for rhizobacteria to stimulate plant growth. IAA supports root elongation and increases the number of root hairs and root laterals thus improving nutrients uptake. It also stimulates seed germination and cell division, delays leaf abscission, and induces flowering and fruiting. Some PGPR thrive in soil enriched with heavy metals and promote plant growth and heavy metal accumulation under otherwise toxic conditions. The bacterial strains inhabiting serpentine outcrops are adapted to high concentrations of heavy metals, partly due to their ability to promote the growth of plants from which they siphon off carbon and nitrogen. Such strains are of interest in agriculture as growth stimulators and in industrial biotechnology. The aim of this study was to isolate metaltolerant rhizobacteria and quantify their production of IAA. The soil samples were collected from two serpentine sites in eastern Bosnia - Mioče and Gornje Cikote. Heavy metal concentrations in the soil samples were measured using flame atomic absorption spectroscopy. Bacterial isolates from the rhizosphere samples were screened for their Cu, Ni and Co tolerance. Rhizosphere samples showed high Cu, Ni and Cr concentrations. Isolates with the strongest heavy metal tolerance were tested for their propensity to produce IAA which was analyzed using a spectrophotometric method with Salkowski reagent. The exact IAA concentrations were calculated from the standard curve. IAA production ranged from 7.55 µg/ml to 901.36 µg/ml with the highest concentration in bacterial culture of isolate from Mioče. According to the DNA sequencing of the 16S rRNA gene, isolate with remarkable production of IAA was identified as Pseudomonas putida, while the isolate with the lowest IAA production showed the highest sequence similarity with the genus Paenarthrobacter (P. nicotinovorans, P. aurescens). Bacterial isolates which showed high IAA concentrations will be further screened for other PGP traits - nitrogen fixation, siderophore production, phosphate solubilization and ACC (1-aminocyclopropane-1-carboxylic acid) deaminase activity. These bacterial isolates will be also used for plant inoculation experiments to test their effects on plant growth and heavy metal tolerance.
- Subjects
BOSNIA &; Herzegovina; INDOLEACETIC acid; PLANT inoculation; PSEUDOMONAS putida; ATOMIC absorption spectroscopy; SERPENTINE; HEAVY metals; COPPER
- Publication
Genetics & Applications, 2023, p33
- ISSN
2566-2937
- Publication type
Article