PDX1.2 is expressed in the basal part of the globular-stage embryo, and plays critical roles in development, hypocotyl elongation, and stress response.
The Arabidopsis thaliana PDX1.2 protein belongs to a small family of three members. While PDX1.1 and PDX1.3 have been extensively described and are well established to function in vitamin B6 biosynthesis, the biological role of PDX1.2 still remains elusive. Here, we show that PDX1.2 is expressed early in embryo development, and that heat shock treatment causes a strong up-regulation of the gene. Using a combined genetic approach of T-DNA insertion lines and expression of artificial micro RNAs, we can show that PDX1.2 is critically required for embryo development, and for normal hypocotyl elongation. Plants with reduced PDX1.2 expression also display reduced primary root growth after heat shock treatments. The work overall provides a set of important new findings that give greater insights into the developmental role of PDX1.2 in plants.
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Bilski P, Li MY, Ehrenshaft M, Daub ME, Chignell CF (2000) Vitamin B6 (pyridoxine) and its derivatives are efficient singlet oxygen quenchers and potential fungal antioxidants. Photochem Photobiol 71:129–134
Chen H, Xiong L (2005) Pyridoxine is required for post-embryonic root development and tolerance to osmotic and oxidative stresses. Plant J 44:396–408
Curtis MD, Grossniklaus U (2003) A gateway cloning vector set for high-throughput functional analysis of genes in planta. Plant Physiol 133:462–469
Denslow SA, Rueschhoff EE, Daub ME (2007) Regulation of the Arabidopsis thaliana vitamin B6 biosynthesis genes by abiotic stress. Plant Physiol Biochem 45:152–161
Estelle MA, Somerville C (1987) Auxin resistant mutants of Arabidopsis thaliana with altered morphology. Mol Gen Genetic 206:200–206
Friml J, Vieten A, Sauer M, Weijers D, Schwarz H, Hamann T, Offringa R, Jürgens G (2003) Efflux-dependent auxin gradients establish the apical-basal axis of Arabidopsis. Nature 426:147–153
Gonzalez E, Danehower D, Daub ME (2007) 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. Plant Physiol 145:985–996
Gray WM, Ostin A, Sandberg G, Romano CP, Estelle M (1998) High temperature promotes auxin-mediated hypocotyl elongation in Arabidopsis. Proc Natl Acad Sci USA 95:7197–7202
Hellmann H, Funck D, Rentsch D, Frommer WB (2000) Hypersensitivity of an Arabidopsis sugar signaling mutant toward exogenous proline application. Plant Physiol 123:779–789
Leasure CD, Chen YP, He ZH (2013) Enhancement of indole-3-acetic acid photodegradation by vitamin B6. Mol Plant 6:1992–1995
Leuendorf JE, Genau A, Szewczyk A, Mooney S, Drewke C, Leistner E, Hellmann H (2008) The Pdx1 family is structurally and functionally conserved between Arabidopsis thaliana and Ginkgo biloba. FEBS J 275:960–969
Leuendorf JE, Osorio S, Szewczyk A, Fernie AR, Hellmann H (2010) Complex assembly and metabolic profiling of Arabidopsis thaliana plants overexpressing vitamin B6 biosynthesis proteins. Mol Plant 3:890–903
Lohmann C, Eggers-Schumacher G, Wunderlich M, Schoffl F (2004) Two different heat shock transcription factors regulate immediate early expression of stress genes in Arabidopsis. Mol Genet Genomics 271:11–21
Mooney S, Hellmann H (2010) Vitamin B6: killing two birds with one stone? Phytochemistry 71:495–501
Mooney S, Leuendorf JE, Hendrickson C, Hellmann H (2009) Vitamin B6: a long known compound of surprising complexity. Molecules 14:329–351
Mooney S, Chen L, Kuhn C, Navarre R, Knowles NR, Hellmann H (2013) Genotype-specific changes in vitamin B6 content and the PDX family in potato. BioMed Res Int 2013:389723
Neuwirth M, Flicker K, Strohmeier M, Tews I, Macheroux P (2007) Thermodynamic characterization of the protein–protein interaction in the heteromeric Bacillus subtilis pyridoxalphosphate synthase. Biochemistry 46:5131–5139
Neuwirth M, Strohmeier M, Windeisen V, Wallner S, Deller S, Rippe K, Sinning I, Macheroux P, Tews I (2009) X-ray crystal structure of Saccharomyces cerevisiae Pdx1 provides insights into the oligomeric nature of PLP synthases. FEBS Lett 583:2179–2186
Raschle T, Amrhein N, Fitzpatrick TB (2005) On the two components of pyridoxal 5′-phosphate synthase from Bacillus subtilis. J Biol Chem 280:32291–32300
Strohmeier M, Raschle T, Mazurkiewicz J, Rippe K, Sinning I, Fitzpatrick TB, Tews I (2006) Structure of a bacterial pyridoxal 5′-phosphate synthase complex. Proc Natl Acad Sci USA 103:19284–19289
Takahashi T, Naito S, Komeda Y (1992) Isolation and analysis of the expression of two genes for the 81-kilodalton heat-shock proteins from Arabidopsis. Plant Physiol 99:383–390
Tambasco-Studart M, Titiz O, Raschle T, Forster G, Amrhein N, Fitzpatrick TB (2005) Vitamin B6 biosynthesis in higher plants. Proc Natl Acad Sci USA 102:13687–13692
Tambasco-Studart M, Tews I, Amrhein N, Fitzpatrick TB (2007) Functional analysis of PDX2 from Arabidopsis, a glutaminase involved in vitamin B6 biosynthesis. Plant Physiol 144:915–925
Titiz O, Tambasco-Studart M, Warzych E, Apel K, Amrhein N, Laloi C, Fitzpatrick TB (2006) PDX1 is essential for vitamin B6 biosynthesis, development and stress tolerance in Arabidopsis. Plant J 48:933–946
Vieten A, Vanneste S, Wisniewska J, Benkova E, Benjamins R, Beeckman T, Luschnig C, Friml J (2005) Functional redundancy of PIN proteins is accompanied by auxin-dependent cross-regulation of PIN expression. Development 132:4521–4531
Wagner S, Bernhardt A, Leuendorf JE, Drewke C, Lytovchenko A, Mujahed N, Gurgui C, Frommer WB, Leistner E, Fernie AR, Hellmann H (2006) Analysis of the Arabidopsis rsr4-1/pd1-3 mutant reveals the critical function of the PDX1 protein family in metabolism, development, and vitamin B6 biosynthesis. Plant Cell 18:1722–1735
We would like to thank Dipika Jadav for technical support. This work was supported by DFG Grant HE3224/6–1 and NSF Grant MCB-1020673 to H.H.
Conflict of interest
The authors declare that they have no conflict of interest.
J. E. Leuendorf and S. L. Mooney equally contributed.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Supplemental Fig. S1 Identification of a homozygous pdx1.2-1 mutant line. a Schematic of the SAIL T-DNA insertion, and primers used to verify that plants were hetero- or homozygous for the insertion in the endogenous PDX1.2 gene. b Representative PCR results on WT and two T2 plants transformed with an Estr-inducible PDX1.2 cDNA sense construct show identification of plants being either hetero- or homozygous for the pdx1.2-1 SAIL T-DNA insertion, respectively (PDF 68 kb)
Supplemental Fig. S2 Constitutive expression of two different amiPDX1.2 constructs lead to aborted seeds. a Schematic drawing of front and middle amiPDX1.2 constructs (triangle) and their target region in PDX1.2. b Picture of mature siliques from WT, and two amiPDX1.2 plants. c Frequency of aborted seeds in different independent amiPDX1.2 lines (PDF 273 kb)
Supplemental Fig. S4 Estradiol inducible amiPDX1.2 lines do not show significant change in root length in the presence of 2,4-D compared to WT. Seedlings were germinated and grown for five days on ATS plates with or without Estr and transferred respectively to plates with or without 50 mM 2,4-D. Root tips were marked and growth was analyzed three days after transfer. Root data are based on at least n = 30 roots. Error bars are standard deviation (PDF 70 kb)
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Leuendorf, J.E., Mooney, S.L., Chen, L. et al. Arabidopsis thaliana PDX1.2 is critical for embryo development and heat shock tolerance. Planta 240, 137–146 (2014). https://doi.org/10.1007/s00425-014-2069-3
- Embryo development
- Heat shock response
- PDX family
- Pyridoxal-5-phosphate synthase
- Vitamin B6