The effect of ascorbic acid and dehydroascorbic acid on the root gravitropic response in Arabidopsis thaliana

• Published in: Plant physiology and biochemistry Vol. 49; no. 8; pp. 909 - 916
• Main Authors: Lee, Yew, Park, Chan Ho, Ram Kim, A., Chang, Soo Chul, Kim, Soo-Hwan, Lee, Woo Sung, Kim, Seong-Ki
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.08.2011; Elsevier
• Subjects: Aldehyde Oxidase - drug effects; Aldehyde Oxidase - genetics; Aldehyde Oxidase - metabolism; Arabidopsis - drug effects; Arabidopsis - physiology; Arabidopsis Proteins - drug effects; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; ascorbate oxidase; ascorbic acid; Ascorbic acid (AA); Ascorbic Acid - metabolism; Ascorbic Acid - pharmacology; Ascorbic acid oxidase (AAO); Biological and medical sciences; biosynthesis; brassinolide; Brassinosteroids; Brassinosteroids - metabolism; dehydroascorbic acid; Dehydroascorbic acid (DHA); Dehydroascorbic Acid - analogs & derivatives; Dehydroascorbic Acid - metabolism; Dehydroascorbic Acid - pharmacology; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; genes; Gravitropism; Gravitropism - physiology; IAA; indole acetic acid; Indoleacetic Acids - metabolism; Movements; mutants; Mutation; Nucleotidyltransferases - genetics; Nucleotidyltransferases - metabolism; Plant physiology and development; Plant Roots - drug effects; Plant Roots - physiology; Redox; root growth; roots; Steroids, Heterocyclic - metabolism; Ascorbic acid (AA); IAA; Redox; Brassinosteroids; Gravitropism; Dehydroascorbic acid (DHA); Ascorbic acid oxidase (AAO); Oxidation reduction; Auxin; Ascorbic acid; Enzyme; Oxidase; Arabidopsis thaliana; Response; Brassinosteroid; Plant physiology; Cruciferae; Indoleacetic acid; Dicotyledones; Angiospermae; Plant growth substance; Spermatophyta; Oxidoreductases; Experimental plant
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2011.05.013

The effects of ascorbic acid (AA) and dehydroascorbic acid (DHA), one of products of the disproportionation of monodehydroascorbate (MDHA) by AA oxidase (AAO, EC 1.10.3.3), on the gravitropic curvature of Arabidopsis roots were characterized by biochemical and genetic approaches. Exogenously applied AA and DHA both stimulated root gravitropic responses in a concentration-dependent fashion. AA also changed the Indole-3-acetic acid (IAA) distribution in the roots after gravistimulation. In an effort to determine the relationship between AA and DHA in the gravitropic response, changes in the amount of reduced AA were evaluated in Arabidopsis under a variety of conditions. The expression level of an AAO gene ( AAO1) was increased upon gravistimulation. Brassinolide (BL), indole-3-acetic acid (IAA), and AA also increased the transcript levels of this gene. Root elongation and the gravitropic response were both suppressed in the AA biosynthesis mutant, vtc1, which has a greatly reduced level of total AA. Furthermore, the line of AAO double mutants ( aao1-1 X aao3-1, 41-21) showed a reduced gravitropic response and reduced root elongation. Taken together, the results of this study imply that both AA and DHA help to determine the redox environment for the root gravitropic response, but DHA, rather than AA, is a major player in the regulation of the gravitropic response mediated by AA in the roots of Arabidopsis thaliana. ► Dehydroascorbic acid and ascorbic acid increased the gravitropic response in the Arabidopsis root. ► Gravity, indole-3-acetic acid (IAA), and brassinolide stimulated the expression of the ASCORBIC ACID OXIDASE 1 ( AAO1) gene. ► The vitamin c1 (v tc1) and the ascorbic acid oxidase ( aao) double mutant showed reduced gravitropic response. ► Ascorbic acid changed the redistribution of IAA in the root after gravity stimulus.