A1 Journal article (refereed)
The reduction of selenium(IV) by boreal Pseudomonas sp. strain T5-6-I : Effects on selenium(IV) uptake in Brassica oleracea (2019)

Lusa, M., Help, H., Honkanen, A.-P., Knuutinen, J., Parkkonen, J., Kalasová, D., & Bomberg, M. (2019). The reduction of selenium(IV) by boreal Pseudomonas sp. strain T5-6-I : Effects on selenium(IV) uptake in Brassica oleracea. Environmental Research, 177, Article 108642. https://doi.org/10.1016/j.envres.2019.108642

JYU authors or editors

Publication details

All authors or editors: Lusa, Merja; Help, Hanna; Honkanen, Ari-Pekka; Knuutinen, Jenna; Parkkonen, Joni; Kalasová, Dominika; Bomberg, Malin

Journal or series: Environmental Research

ISSN: 0013-9351

eISSN: 1096-0953

Publication year: 2019

Volume: 177

Article number: 108642

Publisher: Elsevier

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1016/j.envres.2019.108642

Publication open access: Not open

Publication channel open access: 

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/65298

Publication is parallel published: https://tuhat.helsinki.fi/ws/portalfiles/portal/126271735/Lusa2019_postprint.pdf

Abstract

Selenium (Se) is an essential micronutrient but toxic when taken in excessive amounts. Therefore, understanding the metabolic processes related to selenium uptake and bacteria-plant interactions coupled with selenium metabolism are of high importance. We cultivated Brassica oleracea with the previously isolated heterotrophic aerobic Se(IV)-reducing Pseudomonas sp. T5-6-I strain to better understand the phenomena of bacteria-mediated Se(IV) reduction on selenium availability to the plants. B. oleracea grown on Murashige and Skoog medium (MS-salt agar) with and without of Pseudomonas sp. were amended with Se(IV)/75Se(IV), and selenium transfer into plants was studied using autoradiography and gamma spectroscopy. XANES was in addition used to study the speciation of selenium in the B. oleracea plants. In addition, the effects of Se(IV) on the protein expression in B. oleracea was studied using HPLC-SEC. TEM and confocal microscopy were used to follow the bacterial/Se-aggregate accumulation in plants and the effects of bacterial inoculation on root-hair growth. In the tests using 75Se(IV) on average 130% more selenium was translocated to the B. oleracea plants grown with Pseudomonas sp. compared to the plants grown with selenium, but without Pseudomonas sp. In addition, these bacteria notably increased root hair density. Changes in the protein expression of B. oleracea were observed on the ∼30–58 kDa regions in the Se(IV) treated samples, probably connected e.g. to the oxidative stress induced by Se(IV) or expression of proteins connected to the Se(IV) metabolism. Based on the XANES measurements, selenium appears to accumulate in B. oleracea mainly in organic C-Se-H and C-Se-C bonds with and without bacteria inoculation. We conclude that the Pseudomonas sp. T5-6-I strain seems to contribute positively to the selenium accumulation in plants, establishing the high potential of Se0-producing bacteria in the use of phytoremediation and biofortification of selenium.

Keywords: bacteria; selenium; plant ecology; nutrients (plants); Brassica

Free keywords: bacteria; pseudomonas; selenium; plant uptake; bacteria-plant interactions

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2019

JUFO rating: 2