Biotization of Arabidopsis thaliana with Pseudomonas putida and assessment of its positive effect on "in vitro" growth

• Published in: In vitro cellular & developmental biology. Plant Vol. 56; no. 2; pp. 184 - 192
• Main Authors: Arslan, Ebru, Akkaya, Özlem
• Format: Journal Article
• Language: English
• Published: New York Springer Science + Business Media, LLC 01-04-2020; Springer US; Springer Nature B.V
• Subjects: Accumulation; Acetic acid; Arabidopsis thaliana; Bacteria; Biomedical and Life Sciences; Cell Biology; Colonization; Confocal microscopy; Developmental Biology; Heavy metals; Hydrogen peroxide; Indoleacetic acid; Inoculation; Inoculum; Life Sciences; MICROPROPAGATION; Oxidative stress; Photosynthesis; Phytoremediation; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Plant growth; Plant resistance; Plant Sciences; Potassium; Pseudomonas putida; Seedlings; Seeds; Weight; Germany; Biotization; culture
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1007/s11627-019-10045-z

Determination of the optimal inoculation method and concentration to use for plant-bacteria interaction studies is important in many cases, such as the phytoremediation of heavy metals and other toxic compounds in contaminated areas. The aim of this study was to compare different concentrations and times of inoculation of Pseudomonas putida with various growth stages of Arabidopsis thaliana in 14-d in vitro cultures. A significant beneficial impact of the bacterium was detected in the shoot length and root weight of seedlings. The highest shoot length and root fresh and dry weights were detected in 14-d and 2 × 10³ cfu mL⁻¹ inoculated samples. In addition, the increase in root weight could be visualized with crystal violet staining, as relatively more root hair and lateral root formation occurred in seedlings inoculated with moderate concentrations of bacteria, possibly due to the ability of P. putida to produce indole-acetic acid. Moreover, the highest photosynthetic pigment accumulation was obtained with the highest bacterial inoculum (2 x 10⁶ cfu mL⁻¹), which was tested in 0- or 3-d-old seedlings. Rhizospheric bacterial colonization was also visualized with GFP-labeled bacteria by confocal microscopy. These results showed that biotization of A. thaliana with P. putida KT2440 did not cause severe oxidative stress in seedlings, because H₂O₂ accumulation levels together with CAT and POX activities were not significantly induced. Therefore, this strain could be used for several applications based on plant-bacteria interactions.