title: Physiological characterization of aluminum tolerance and accumulation in tartary and wild buckwheat.
abstract: Ionic aluminum (Al) is toxic for plant growth, but some plant species are able to accumulate Al at high concentrations without showing toxicity symptoms. In order to determine whether other species in the genus Fagopyrum are able to accumulate Al like common buckwheat (Fagopyrum esculentum), we investigated the external and internal detoxification mechanisms of Al in two self-compatible species: tartary (Fagopyrum tataricum) and wild buckwheat (Fagopyrum homotropicum). Both tartary and wild buckwheat showed high Al tolerance comparable to common buckwheat. Furthermore, these two species also secreted oxalate rapidly from the roots in response to Al in a time-dependent manner. Both tartary and wild buckwheat accumulated > 1 mg g(-1) Al in the leaves after short-term exposure to Al. Analysis with (27) Al-nuclear magnetic resonance (NMR) revealed that Al was present in the form of Al-oxalate (1 : 3 ratio) in the roots and leaves, but in the form of Al-citrate (1 : 1 ratio) in the xylem sap in both species. These results indicate that similar to common buckwheat, both tartary and wild buckwheat detoxify Al externally and internally, respectively, by secreting oxalate from the roots and by forming the Al-oxalate complex, which is a nonphytotoxic form. These features of Al response and accumulation may be conserved in genus Fagopyrum.
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, 710-0046, Japan; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Rong Fu
authors.initials: RF
authors.lastname: Chen
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwashita
authors.forename: Ren Fang
authors.initials: RF
authors.lastname: Shen
authors.forename: Jian Feng
authors.initials: JF
authors.lastname: Ma
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000535:Aluminum / Q000378:metabolism* / Q000633:toxicity*; D019612:Fagopyrum / Q000187:drug effects* / Q000502:physiology*; D009682:Magnetic Resonance Spectroscopy; D010070:Oxalates / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D012492:Salts / Q000378:metabolism; D013997:Time Factors; D052584:Xylem / Q000187:drug effects / Q000378:metabolism
chemical_list: D010070:Oxalates; D012492:Salts; D000535:Aluminum
keywords: 27Al-nuclear magnetic resonance (NMR); Al form; Fagopyrum; aluminum (Al) accumulation; organic acid secretion