title: Two-way transfer of nitrogen between Dalbergia odorifera and its hemiparasite Santalum album is enhanced when the host is effectively nodulated and fixing nitrogen.
abstract: Nutrient translocation from a host plant is vital to the growth and survival of its root parasitic plant, but few studies have investigated whether a parasitic plant is also able to transfer nutrients to its host. The role of N2-fixation in nitrogen (N) transfer between 7-month-old Dalbergia odorifera T. Chen nodulated with Bradyrhizobium elkanii DG and its hemiparasite Santalum album Linn. was examined by external (15)N labeling in a pot study. Four paired treatments were used, with (15)N given to either host or hemiparasite and the host either nodulated or grown on combined N. N2-fixation supplied 41-44% of total N in D. odorifera. Biomass, N and (15)N contents were significantly greater in both nodulated D. odorifera and S. album grown with paired nodulated D. odorifera. Significantly higher total plant (15)N recovery was in N donor D. odorifera (68-72%) than in N donor S. album (42-44%), regardless of the nodulation status in D. odorifera. Nitrogen transfer to S. album was significantly greater (27.8-67.8 mg plant(-1)) than to D. odorifera (2.0-8.9 mg plant(-1)) and 2.4-4.5 times greater in the nodulated pair than in the non-nodulated pair. Irrespective of the nodulation status, S. album was always the N-sink plant. The amount of two-way N transfer was increased by the presence of effective nodules, resulting in a greater net N transfer (22.6 mg plant(-1)) from host D. odorifera to hemiparasite S. album. Our results may provide N management strategies for D. odorifera/S. album mixed plantations in the field.
authors.affiliation: Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangdong 510520, China.
authors.forename: J K
authors.initials: JK
authors.lastname: Lu
authors.forename: L H
authors.initials: LH
authors.lastname: Kang
authors.forename: J I
authors.initials: JI
authors.lastname: Sprent
authors.forename: D P
authors.initials: DP
authors.lastname: Xu
authors.forename: X H
authors.initials: XH
authors.lastname: He
mesh_terms: D001692:Biological Transport; D018533:Biomass; D020369:Bradyrhizobium / Q000254:growth & development / Q000378:metabolism*; D035782:Dalbergia / Q000254:growth & development / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation / Q000502:physiology*; D009587:Nitrogen Isotopes / Q000032:analysis; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism; D053204:Root Nodules, Plant / Q000254:growth & development / Q000378:metabolism; D032123:Santalum / Q000254:growth & development / Q000378:metabolism*; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism
chemical_list: D009587:Nitrogen Isotopes; D009584:Nitrogen
keywords: Bradyrhizobium; Dalbergia odorifera; Santalum album; haustorium; hemiparasite; nitrogen fixation; two-way N transfer