title: Effect of external phosphate addition on solid-phase iron distribution and iron accumulation in Mangrove Kandelia obovata (S. L.).
abstract: In this study, a pot experiment was conducted to evaluate the effect of phosphate (PO4 (3-)) addition on iron (Fe) cycling in mangrove ecosystem. Kandelia obovata (S. L.), one of the dominant mangrove species in the southeast of China, was cultivated in rhizoboxes under three different levels of P concentrations. Results showed the solid-phase Fe distribution and Fe(II)/Fe(III) values in both the root zone (rhizosphere) and bulk soil (non-rhizosphere) were comparable among all P levels (p > 0.05); P addition significantly decreased the pore water Fe content both in the rhizosphere and non-rhizosphere zone (p < 0.05); higher amount of reactive Fe was found in rhizosphere sediments, while in the non-rhizosphere sediments, higher concentration of crystalline Fe was determined; P significantly increased iron plaque formation and iron accumulation in K. obovata (S. L.) tissues (p < 0.05); P addition increased K. obovata (S. L.) biomass and chlorophyll content. It was suggested that P is implicated in the Fe cycling in mangrove plants; more reactive iron, higher abundance of root Fe-reducing bacteria (FeRB) and Fe-oxidizing bacteria (FeOB), and together with higher amount of K. obovata (S. L.) root organic acids exudation result in a rapid Fe cycling in rhizosphere, which contribute to comparable solid-phase iron distribution among different P levels.
authors.affiliation: Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen, 361005, China.
authors.forename: Jingna
authors.initials: J
authors.lastname: Du
authors.forename: Jingchun
authors.initials: J
authors.lastname: Liu
authors.forename: Haoliang
authors.initials: H
authors.lastname: Lu
authors.forename: Dennis
authors.initials: D
authors.lastname: Hansell
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zhang
authors.forename: Wenyun
authors.initials: W
authors.lastname: Wang
authors.forename: Chongling
authors.initials: C
authors.lastname: Yan
mesh_terms: D001419:Bacteria; D018533:Biomass; D002681:China; D007501:Iron / Q000032:analysis*; D010710:Phosphates / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects; D043982:Rhizophoraceae / Q000737:chemistry / Q000187:drug effects; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry*; D014867:Water
chemical_list: D010710:Phosphates; D012987:Soil; D014867:Water; D007501:Iron