Regulation of biosynthetic genes and antioxidant properties of vitamin B6 vitamers during plant defense responses

Denslow, Sheri; Walls, Amanda A.; Daub, Margaret E.

doi:10.1016/j.pmpp.2005.09.004

Cited by 103 publications

(107 citation statements)

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“…PMP/PNP oxidase (PDX3) and PL kinase (SOS4) are key enzymes involved in the vitamin B 6 salvage pathway in Arabidopsis Sang et al, 2007), where the nonphosphorylated forms of vitamin B 6 are converted to PLP, the active cofactor of vitamin B 6 , essential in many aspects of primary metabolism. Additionally, vitamin B 6 has been linked to stress responses in plants Denslow et al, 2005Denslow et al, , 2007Sang et al, 2007) and is essential for root development Chen and Xiong, 2005;Titiz et al, 2006). Therefore, it is not surprising that Arabidopsis pdx3 and sos4 plants are affected in their growth and development under normal growth and stress conditions.…”

Section: Discussionmentioning

confidence: 99%

“…PLP is also involved in enzymes that catalyze some steps in carbohydrate and lipid metabolism and is a cofactor for aminocyclopropane-1-carboxylate synthase. Moreover, vitamin B 6 has been linked to resistance to oxidative and environmental stresses and is an efficient singlet oxygen quencher and antioxidant Denslow et al, 2005Denslow et al, , 2007. It is required for postembryonic root development and root hair development in plants Chen and Xiong, 2005;Denslow et al, 2005Denslow et al, , 2007Titiz et al, 2006).…”

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confidence: 99%

“…This enzyme complex catalyzes a reaction where Gln plus either Rib 5-P or ribulose 5-P and either dihydroxyacetone phosphate or glyceraldehyde 3-P are used to produce PLP, the first B 6 vitamer synthesized in this pathway (Burns et al, 2005;Raschle et al, 2005). PDX1 and PDX2 were recently isolated and characterized in tobacco (Nicotiana tabacum; Denslow et al, 2005) and Arabidopsis (Chen and Xiong, 2005;TambascoStudart et al, 2005;Titiz et al, 2006;Wagner et al, 2006;Denslow et al, 2007). Two PDX1 sequences were recovered from tobacco, suggesting either two copies or two alleles; one copy of PDX2 was identified.…”

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Vitamer Levels, Stress Response, Enzyme Activity, and Gene Regulation of Arabidopsis Lines Mutant in the Pyridoxine/Pyridoxamine 5′-Phosphate Oxidase (PDX3) and the Pyridoxal Kinase (SOS4) Genes Involved in the Vitamin B6 Salvage Pathway

2007

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PDX3 and SALT OVERLY SENSITIVE4 (SOS4), encoding pyridoxine/pyridoxamine 5#-phosphate oxidase and pyridoxal kinase, respectively, are the only known genes involved in the salvage pathway of pyridoxal 5#-phosphate in plants. In this study, we determined the phenotype, stress responses, vitamer levels, and regulation of the vitamin B 6 pathway genes in Arabidopsis (Arabidopsis thaliana) plants mutant in PDX3 and SOS4. sos4 mutant plants showed a distinct phenotype characterized by chlorosis and reduced plant size, as well as hypersensitivity to sucrose in addition to the previously noted NaCl sensitivity. This mutant had higher levels of pyridoxine, pyridoxamine, and pyridoxal 5#-phosphate than the wild type, reflected in an increase in total vitamin B 6 observed through HPLC analysis and yeast bioassay. The sos4 mutant showed increased activity of PDX3 as well as of the B 6 de novo pathway enzyme PDX1, correlating with increased total B 6 levels. Two independent lines with T-DNA insertions in the promoter region of PDX3 (pdx3-1 and pdx3-2) had decreased PDX3 activity. Both also had decreased activity of PDX1, which correlated with lower levels of total vitamin B 6 observed using the yeast bioassay; however, no differences were noted in levels of individual vitamers by HPLC analysis. Both pdx3 mutants showed growth reduction in vitro and in vivo as well as an inability to increase growth under high light conditions. Increased expression of salvage and some of the de novo pathway genes was observed in both the pdx3 and sos4 mutants. In all mutants, increased expression was more dramatic for the salvage pathway genes.

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confidence: 99%

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Vitamer Levels, Stress Response, Enzyme Activity, and Gene Regulation of Arabidopsis Lines Mutant in the Pyridoxine/Pyridoxamine 5′-Phosphate Oxidase (PDX3) and the Pyridoxal Kinase (SOS4) Genes Involved in the Vitamin B6 Salvage Pathway

2007

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“…Although vitamin B 6 has been previously implicated in defense (Denslow et al, 2005), the upregulation of specific pathogen response genes and increased salicylic acid content of pdx3 was unanticipated and initially suggested that PDX3 contributes to repression of pathogen responses. In fact, the stunted shoot growth, early flowering, dwarfism, and reduced seed yield of pdx3 are hallmarks of mutants that show constitutive defense responses in the absence of pathogen infection, i.e., autoimmune mutants (Todesco et al, 2010;Alcázar and Parker, 2011).…”

Section: Pdx3 Plays An Important Role In Nitrogen Metabolismmentioning

confidence: 99%

Balancing of B₆ Vitamers Is Essential for Plant Development and Metabolism in Arabidopsis

et al. 2016

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Vitamin B 6 comprises a family of compounds that is essential for all organisms, most notable among which is the cofactor pyridoxal 59-phosphate (PLP). Other forms of vitamin B 6 include pyridoxamine 59-phosphate (PMP), pyridoxine 59-phosphate (PNP), and the corresponding nonphosphorylated derivatives. While plants can biosynthesize PLP de novo, they also have salvage pathways that serve to interconvert the different vitamers. The selective contribution of these various pathways to cellular vitamin B 6 homeostasis in plants is not fully understood. Although biosynthesis de novo has been extensively characterized, the salvage pathways have received comparatively little attention in plants. Here, we show that the PMP/PNP oxidase PDX3 is essential for balancing B 6 vitamer levels in Arabidopsis thaliana. In the absence of PDX3, growth and development are impaired and the metabolite profile is altered. Surprisingly, RNA sequencing reveals strong induction of stress-related genes in pdx3, particularly those associated with biotic stress that coincides with an increase in salicylic acid levels. Intriguingly, exogenous ammonium rescues the growth and developmental phenotype in line with a severe reduction in nitrate reductase activity that may be due to the overaccumulation of PMP in pdx3. Our analyses demonstrate an important link between vitamin B 6 homeostasis and nitrogen metabolism.

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“…Vitamin B 6 is necessary in the synthesis of both serotonin and GABA neurotransmitters that control depression, pain perception, and anxiety. Most vitamin B 6 -dependent enzymes catalyze reactions including transamination, decarboxylation, dehydration, desulfhydration, racemization, cleavage, and synthesis, among other processes including the activation of glycine during the initial stages of heme production (Bui and Small 2012; Denslow et al 2005;Sorolla et al, 2010). Interestingly, vitamin B 6 has recently been found to be a potent antioxidant, with the particular ability to quench reactive oxygen species such as superoxide, and singlet oxygen (Tambasco-Studart et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Detection of B6 Vitamers in Grain Products: Experimental and Computational Studies

et al. 2017

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A reversed phase high-performance liquid chromatography method (HPLC) with coulometric electrochemical detection has been applied and validated for the simultaneous analysis of pyridoxamine (PM), pyridoxal (PL), and pyridoxine (PN) in cereal products. Isocratic separation was achieved using a C 18 column with a mobile phase consisting of methanol-phosphate buffer (10:90) and 0.018 M trimethylamine adjusted to pH 3.55 with 85% orthophosphoric acid. The limits of detection for PM, PL, and PN were 0.28, 0.36, and 0.43 ng mL −1 , respectively, with vitamins recoveries ranging from 90.4 to 98.1%. The applied method for the analysis of B 6 vitamins naturally present in grain products, offers a simple and fast sample preparation without derivatization. To understand vitamer separation further, methods of computational chemistry were employed. Specifically, density functional theory (DFT) was used to determine electrostatic potentials, as well as the charges of each vitamer. A number of correlations were established between these properties and elution order.

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Regulation of biosynthetic genes and antioxidant properties of vitamin B6 vitamers during plant defense responses

Cited by 103 publications

References 59 publications

Vitamer Levels, Stress Response, Enzyme Activity, and Gene Regulation of Arabidopsis Lines Mutant in the Pyridoxine/Pyridoxamine 5′-Phosphate Oxidase (PDX3) and the Pyridoxal Kinase (SOS4) Genes Involved in the Vitamin B6 Salvage Pathway

Vitamer Levels, Stress Response, Enzyme Activity, and Gene Regulation of Arabidopsis Lines Mutant in the Pyridoxine/Pyridoxamine 5′-Phosphate Oxidase (PDX3) and the Pyridoxal Kinase (SOS4) Genes Involved in the Vitamin B6 Salvage Pathway

Balancing of B₆ Vitamers Is Essential for Plant Development and Metabolism in Arabidopsis

Detection of B6 Vitamers in Grain Products: Experimental and Computational Studies

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Regulation of biosynthetic genes and antioxidant properties of vitamin B6 vitamers during plant defense responses

Cited by 103 publications

References 59 publications

Vitamer Levels, Stress Response, Enzyme Activity, and Gene Regulation of Arabidopsis Lines Mutant in the Pyridoxine/Pyridoxamine 5′-Phosphate Oxidase (PDX3) and the Pyridoxal Kinase (SOS4) Genes Involved in the Vitamin B6 Salvage Pathway

Vitamer Levels, Stress Response, Enzyme Activity, and Gene Regulation of Arabidopsis Lines Mutant in the Pyridoxine/Pyridoxamine 5′-Phosphate Oxidase (PDX3) and the Pyridoxal Kinase (SOS4) Genes Involved in the Vitamin B6 Salvage Pathway

Balancing of B6 Vitamers Is Essential for Plant Development and Metabolism in Arabidopsis

Detection of B6 Vitamers in Grain Products: Experimental and Computational Studies

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Balancing of B₆ Vitamers Is Essential for Plant Development and Metabolism in Arabidopsis