Evaluation of the plant growth-promoting activity of Pseudomonas nitroreducens in Arabidopsis thaliana and Lactuca sativa

Abstract

Pseudomonas nitroreducens: strain IHB B 13561 (PnIHB) enhances the growth of Arabidopsis thaliana and Lactuca sativa via the stimulation of cell development and nitrate absorption. Plant growth-promoting rhizobacteria (PGPR) enhance plant development through various mechanisms; they improve the uptake of soil resources by plants to greatly promote plant growth. Here, we used Arabidopsis thaliana seedlings and Lactuca sativa to screen the growth enhancement activities of a purified PGPR, Pseudomonas nitroreducens strain IHB B 13561 (PnIHB). When cocultivated with PnIHB, both species of plants exhibited notably improved growth, particularly in regard to biomass. Quantitative reverse transcription polymerase chain reaction analysis indicated high expression levels of the nitrate transporter genes, especially NRT2.1, which plays a major role in the high-affinity nitrate transport system in roots. Moreover, enhanced activity of the cyclin-B1 promoter was observed when wild-type 'Columbia-0' Arabidopsis seedlings were exposed to PnIHB, whereas upregulation of cyclin-B also occurred in the inoculated lettuce seedlings. Overall, these results suggest that PnIHB improves A. thaliana and L. sativa growth via specific pathways involved in the promotion of cell development and enhancement of nitrate uptake.

Integration of A Nitrate-Related Signaling Pathway in Rhizobia-Induced Responses During Interactions with Non-Legume Host Arabidopsis thaliana

“…4). A similar effect was observed for NRT2.1 upon inoculation of Arabidopsis and Lactuca sativa roots with the PGPR Pseudomonas nitroreducens (Trinh et al, 2018).…”

Pseudomonas PS01 Isolated from Maize Rhizosphere Alters Root System Architecture and Promotes Plant Growth

“…This methodology has shown that a large number of PGPRs may modify the RSA as well as root functionality, leading to the increase in uptake of nutrients and water and improve the overall growth of the whole plant [47]. A common pattern of root architecture adaptation to PGPR, including the reduction of the primary roots growth, was enhanced lateral root branching and development of root hairs was also documented [3,5,52,59]. In this study, PS01 altered the Arabidopsis RSA by inhibiting primary root elongation and promoting lateral root and root hair formation.…”

“…Plates were kept vertically in the growth chamber at 22 • C with a photoperiod of 16 h light and 8 h dark. Four days after germination, uniform seedlings with similar size were transferred onto new (MS 1 2 ) solid medium plates as described previously [5].…”

“…The genus Pseudomonas is one of the most abundant genera of PGPR, which is capable of enhancing plant growth and modulating the root system architecture in different plant species [2][3][4]. For examples, Pseudomonas nitroreducens enhances the growth of Arabidopsis thaliana and Lactuca sativa [5]; Pseudomonas putida, Pseudomonas aeruginosa and Pseudomonas fluorescens stimulate growth of various crop plants such as maize (Zea mays), soybean (Glycine max), wheat (Triticum), peanut (Arachis hypogaea) and mung bean (Vigna radiata) [6][7][8][9][10][11]. In addition, Pseudomonas spp.…”

Transcriptomics reveal core activities of the plant growth-promoting bacterium Delftia acidovorans RAY209 during interaction with canola and soybean roots

“…Supporting this hypothesis, a legume pectate lyase has been shown to be necessary for successful nodulation by rhizobial symbionts [39], and other hydrolases are known to be important for rhizobium root infection [40]. Furthermore, the increased expression of a predicted nitrate transporter by soybean roots during sustained RAY209 colonization is similar to the reported activity of the PGPR Pseudomonas nitroreducens in Arabidopsis thaliana, where plant-nitrate transport gene expression is up-regulated in the presence of the PGPR to support nitrogen uptake [41].…”