Bacterial siderophores efficiently provide iron to iron-starved tomato plants in hydroponics culture

Abstract

Iron is one of the essential elements for a proper plant development. Providing plants with an accessible form of iron is crucial when it is scant or unavailable in soils. Chemical chelates are the only current alternative and are highly stable in soils, therefore, posing a threat to drinking water. The aim of this investigation was to quantify siderophores produced by two bacterial strains and to determine if these bacterial siderophores would palliate chlorotic symptoms of iron-starved tomato plants. For this purpose, siderophore production in MM9 medium by two selected bacterial strains was quantified, and the best was used for biological assay. Bacterial culture media free of bacteria (S) and with bacterial cells (BS), both supplemented with Fe were delivered to 12-week-old plants grown under iron starvation in hydroponic conditions; controls with full Hoagland solution, iron-free Hoagland solution and water were also conducted. Treatments were applied twice along the experiment, with a week in between. At harvest, plant yield, chlorophyll content and nutritional status in leaves were measured. Both the bacterial siderophore treatments significantly increased plant yield, chlorophyll and iron content over the positive controls with full Hoagland solution, indicating that siderophores are effective in providing Fe to the plant, either with or without the presence of bacteria. In summary, siderophores from strain Chryseobacterium C138 are effective in supplying Fe to iron-starved tomato plants by the roots, either with or without the presence of bacteria. Based on the amount of siderophores produced, an effective and economically feasible organic Fe chelator could be developed.

The Rebirth of Culture in Microbiology through the Example of Culturomics To Study Human Gut Microbiota

“…The use of cyclic AMP (cAMP), N-butyryl homoserine lactone, or N-oxohexanoyl-DL-homoserine lactone at a low concentration of 10 M permitted an increase in the microbial recovery of heterotrophic bacteria from the central Baltic Sea (146). The concept of mutualism between bacterial species emerged and was significantly highlighted by the role of siderophores (147)(148)(149). D'Onofrio et al identified 5 new acyldesferrioxamine siderophores isolated from Micrococcus luteus KLE1011, permitting the culture of a substantial number of marine bacterial species previously considered to be uncultivable (147).…”

Fortification of micronutrients for efficient agronomic production: a review

“…Here, siderophores, metal chelators produced by beneficial microbes in response to Fe scarcity, play a role in depriving pathogens of Fe, as well as in availing plants with Fe and other metallic micronutrients (Kloepper et al 1980;Lim and Kim 1997;Vansuyt et al 2007;Dimkpa et al 2009Dimkpa et al , 2015a. This role is the basis for the use of siderophoreproducing bacteria, or siderophores extracted from bacteria, as biofertilizers to supply Fe to plants (Fernandez et al 2005;Radzki et al 2013). In contrast to Fe, Zn may act both directly and indirectly in plant-pathogen systems.…”

Mecanismos de acción de hongos y bacterias empleados como biofertilizantes en suelos agrícolas: una revisión sistemática

“…Sin embargo, las plantas no poseen la capacidad de sintetizarlo, además de que el contenido total de fósforo en los suelos promedios es de 0,05 %, y únicamente el 0,1 % del total de fósforo presente en esta matriz está en forma disponible para las plantas, ya que la mayor parte está en forma insoluble como parte de fosfatos de calcio y hierro (Radzki et al 2013). Por lo anterior, se hace conveniente la aplicación de microorganismos solubilizadores de fosfato.…”