title: Influence of N deficiency and salinity on metal (Pb, Zn and Cu) accumulation and tolerance by Rhizophora stylosa in relation to root anatomy and permeability.
abstract: Effects of N deficiency and salinity on root anatomy, permeability and metal (Pb, Zn and Cu) translocation and tolerance were investigated using mangrove seedlings of Rhizophora stylosa. The results showed that salt could directly reduce radial oxygen loss (ROL) by stimulation of lignification within exodermis. N deficiency, oppositely, would reduce lignification. Such an alteration in root permeability may also influence metal tolerance by plants. The data indicated that a moderate salinity could stimulate a lignified exodermis that delayed the entry of metals into the roots and thereby contributed to a higher metal tolerance, while N deficiency would aggravate metal toxicity. The results from sand pot trail further confirmed this issue. This study provides a barrier property of the exodermis in dealing with environments. The plasticity of root anatomy is likely an adaptive strategy to regulate the fluxes of gases, nutrients and toxins at root-soil interface.
authors.affiliation: State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Cheng
authors.forename: You-Shao
authors.initials: YS
authors.lastname: Wang
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Ye
authors.forename: Dan-Ting
authors.initials: DT
authors.lastname: Chen
authors.forename: Yu-Tu
authors.initials: YT
authors.lastname: Wang
authors.forename: Ya-Lan
authors.initials: YL
authors.lastname: Peng
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Wang
mesh_terms: D000222:Adaptation, Physiological; D001673:Biodegradation, Environmental; D008670:Metals / Q000378:metabolism* / Q000633:toxicity; D009584:Nitrogen / Q000172:deficiency* / Q000378:metabolism; D010539:Permeability; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D043982:Rhizophoraceae / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D054712:Salinity; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D009584:Nitrogen