title: Proteomic analysis of Arabidopsis thaliana leaves in response to acute boron deficiency and toxicity reveals effects on photosynthesis, carbohydrate metabolism, and protein synthesis.
abstract: Boron (B) stress (deficiency and toxicity) is common in plants, but as the functions of this essential micronutrient are incompletely understood, so too are the effects of B stress. To investigate mechanisms underlying B stress, we examined protein profiles in leaves of Arabidopsis thaliana plants grown under normal B (30 μM), compared to plants transferred for 60 and 84 h (i.e., before and after initial visible symptoms) in deficient (0 μM) or toxic (3 mM) levels of B. B-responsive polypeptides were sequenced by mass spectrometry, following 2D gel electrophoresis, and 1D gels and immunoblotting were used to confirm the B-responsiveness of some of these proteins. Fourteen B-responsive proteins were identified, including: 9 chloroplast proteins, 6 proteins of photosynthetic/carbohydrate metabolism (rubisco activase, OEC23, photosystem I reaction center subunit II-1, ATPase δ-subunit, glycolate oxidase, fructose bisphosphate aldolase), 6 stress proteins, and 3 proteins involved in protein synthesis (note that the 14 proteins may fall into multiple categories). Most (8) of the B-responsive proteins decreased under both B deficiency and toxicity; only 3 increased with B stress. Boron stress decreased, or had no effect on, 3 of 4 oxidative stress proteins examined, and did not affect total protein. Hence, our results indicate relatively early specific effects of B stress on chloroplasts and protein synthesis.
authors.affiliation: Department of Environmental Sciences, University of Toledo, Toledo, OH 43606, USA.
authors.forename: Mei
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Environmental Sciences, University of Toledo, Toledo, OH 43606, USA. Electronic address: sasmita.mishra@utoledo.edu.
authors.forename: Sasmita
authors.initials: S
authors.lastname: Mishra
authors.affiliation: Department of Environmental Sciences, University of Toledo, Toledo, OH 43606, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Heckathorn
authors.affiliation: United States Department of Agriculture-Agricultural Research Service, University of Toledo, Toledo, OH 43606, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Frantz
authors.affiliation: United States Department of Agriculture-Agricultural Research Service, University of Toledo, Toledo, OH 43606, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Krause
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D001895:Boron / Q000172:deficiency* / Q000633:toxicity*; D050260:Carbohydrate Metabolism / Q000187:drug effects*; D010788:Photosynthesis / Q000187:drug effects*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects*; D020543:Proteome
chemical_list: D020543:Proteome; D001895:Boron
keywords: B-deficiency; B-toxicity; Photosynthesis