Use of plant growth promoting bacterial strains to improve Cytisus striatus and Lupinus luteus development for potential application in phytoremediation

Abstract

Plant growth promoting (PGP) bacterial strains possess different mechanisms to improve plant development under common environmental stresses, and are therefore often used as inoculants in soil phytoremediation processes. The aims of the present work were to study the effects of a collection of plant growth promoting bacterial strains on plant development, antioxidant enzyme activities and nutritional status of Cytisus striatus and/or Lupinus luteus plants a) growing in perlite under non-stress conditions and b) growing in diesel-contaminated soil. For this, two greenhouse experiments were designed. Firstly, C. striatus and L. luteus plants were grown from seeds in perlite, and periodically inoculated with 6 PGP strains, either individually or in pairs. Secondly, L. luteus seedlings were grown in soil samples of the A and B horizons of a Cambisol contaminated with 1.25% (w/w) of diesel and inoculated with best PGP inoculant selected from the first experiment. The results indicated that the PGP strains tested in perlite significantly improved plant growth. Combination treatments provoked better growth of L. luteus than the respective individual strains, while individual inoculation treatments were more effective for C. striatus. L. luteus growth in diesel-contaminated soil was significantly improved in the presence of PGP strains, presenting a 2-fold or higher increase in plant biomass. Inoculants did not provoke significant changes in plant nutritional status, with the exception of a subset of siderophore-producing and P-solubilising bacterial strains that resulted in significantly modification of Fe or P concentrations in leaf tissues. Inoculants did not cause significant changes in enzyme activities in perlite experiments, however they significantly reduced oxidative stress in contaminated soils suggesting an improvement in plant tolerance to diesel. Some strains were applied to non-host plants, indicating a non-specific performance of their plant growth promotion. The use of PGP strains in phytoremediation may help plants to overcome contaminant and other soil stresses, increasing phytoremediation efficiency.

Inoculation of Pseudomonas putida in Farmer Environment to Improve Growth and Yield: Maize (Zea mays L.) Trial in Sothern, Central and Northern (Benin)

“…These results also concur with those of [34] and [35], who demonstrated significant growths of maize plants with PGPR inoculation, particularly in height and diameter at the crown. [36,37] reported the beneficial effect of PGPR inoculation on plant growth. PGPRs have been reported to promote host plant growth through various mechanisms such as nitrogen (N2) fixation and solubilization of trace elements such as phosphate (P), [11,38].…”

Study of the Modulating Interactions of Multitrait Rhizobacteria Using Zea Mays L. as the Host Plant

“…through HCN production or even by collaborating with other beneficial microorganisms 4 . Balseiro-Romero et al (2017) and many other researchers working on the effect of PGPR on growth parameters of various plants reported that shoot length increased in their experiments 20 . The present study demonstrated that out of the ten bacterial strains, five bacterial strains namely Cn5, Streptomyces lydicus (Cn6), Bacillus subtilis (Cn2), Cn4 and PP4 showed considerable percentage increase of more than 50% in root length over control.…”

Assessment of plant growth-promoting stress-tolerant endophytes screened from Bougainvillea glabra for the growth of Triticum aestivum L. and Zea mays

“…In natural environment, plants have to combat various biotic and abiotic stresses (Balseiro-Romero et al, 2017). Abiotic stressors are classified as inanimate components associated with the environment whose effect is experienced by the living organisms of nature (Jasim et al, 2015).…”