Abstract
Conventional agriculture relies on chemical pesticides and fertilizers, which can degrade ecosystems. A reduction of these harmful practices is required, replacing (or integrating) them with more eco-friendly approaches, such as microbial inoculation. Tomato is an important agricultural product, with a high content of bioactive compounds (folate, ascorbate, polyphenols, and carotenoids). The focus of this research was to investigate the plant growth-promoting (PGP) abilities of bacterial strains isolated from different tomato cultivars, with the aim to develop systems to improve plant health and crop productivity based on microbial inoculation. A pool of different tomato cultivars already available on the market and new tomato hybrids were selected based on their nutritional quality (high content of biologically active compounds). A total of 23 strains were isolated from tomato roots (11 rhizospheric strains and 12 root endophytes). The cultivable isolates were analyzed for a number of different PGP traits: organic acids (OA), indole acetic acid (IAA), ACC deaminase, and siderophore production. The effects of microbial inoculation on root growth of Arabidopsis thaliana were also evaluated using a Vertical Agar Plate assay. A high percentage of the isolated strains tested positive for the following PGP traits: 73 % were able to produce OA, 89 % IAA, 83 % ACC deaminase, and 87 % siderophores. The most striking result were remarkable increases in the formation of root hairs for most of the inoculated plants. This effect was obvious for all A. thaliana seedlings inoculated with the isolated endophytes, and for the 50 % of the seedlings inoculated with the rhizospheric strains. A better knowledge of the plant growth-promotion activity of these strains can provide an important contribution to increase environmental sustainability in agriculture.
Highlights
Conventional agriculture relies on chemical pesticides and fertilizers, which can degrade ecosystems
Agric. (2016) 3:1 be drawn between bacteria residing in the rhizosphere or phyllosphere and bacteria living inside the plant, the so-called endophytes
Genotypic characterization After the isolation, all morphologically different bacteria were purified, but only 2/3 of the strains showed to be cultivable in the subsequent steps; 16S rDNAbased identification was performed on 15 strains (6 rhizospheric and 9 endophytic strains)
Summary
Conventional agriculture relies on chemical pesticides and fertilizers, which can degrade ecosystems. Established strategies to enhance crop productivity are the use of chemical fertilizers, manures, and pesticides These approaches often have a negative impact on the environment: leaching of nitrate into. Endophytic bacteria reside in specific tissues of the plant (such as root cortex or xylem) and develop a close association with the plant, with exchange of nutrients, enzymes (lipase, catalase, oxidase, etc.), functional agents (siderophores, biosurfactants, etc.), and “signals” [9, 10]. Endophytes colonize their plant host tissues in which they persist without exerting the negative effects of a pathogen (disruption of respiration, photosynthesis, translocation of nutrients, transpiration, etc.). Plant growth-promoting bacteria promote plant health and growth via three mechanisms: phytostimulation, biofertilization, and biocontrol [11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Chemical and Biological Technologies in Agriculture
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
