The Interactions Between Root Exudates From Iron-deficient Red Clover (Trifolium Pratense L.) And Soil Microorganism In Rhizosphere

Red clover (Trifolium pratense L. cv. kenland) roots can release a substantial amount of phenolic compounds under Fe deficient condition. However, so far what's the effect(s) of these phenolic compounds on improving plant iron acquisition is still unclear. Since most phenolic compounds are toxic to microorganisms, they would have great impacts on microbial communities in the rhizosphere of red clover. In the present study, one bacterium was selected from calcareous soils on the basis of tolerance to phenolic root exudates from red clover under Fe deficiency in liquid culture medium. The 16S rDNA sequencing analysis identified this bacterium the genus Pseudomonas. We temporarily named this strain Pseudomonas sp. yy (P. yy). Further study showed that this strain could not degrade or utilize phenol as carbon source, but could tolerate phenol stress (600 mg 1^-1). The growth rates of the strain were significantly higher in both +FeCl₃ (10μM) and + Fe(OH)₃ (200 mg 1^-1) media than...