title: The phosphorylated pathway of serine biosynthesis is essential both for male gametophyte and embryo development and for root growth in Arabidopsis.
abstract: This study characterizes the phosphorylated pathway of Ser biosynthesis (PPSB) in Arabidopsis thaliana by targeting phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Lack of PSP1 activity delayed embryo development, leading to aborted embryos that could be classified as early curled cotyledons. The embryo-lethal phenotype of psp1 mutants could be complemented with PSP1 cDNA under the control of Pro35S (Pro35S:PSP1). However, this construct, which was poorly expressed in the anther tapetum, did not complement mutant fertility. Microspore development in psp1.1/psp1.1 Pro35S:PSP1 arrested at the polarized stage. The tapetum from these lines displayed delayed and irregular development. The expression of PSP1 in the tapetum at critical stages of microspore development suggests that PSP1 activity in this cell layer is essential in pollen development. In addition to embryo death and male sterility, conditional psp1 mutants displayed a short-root phenotype, which was reverted in the presence of Ser. A metabolomic study demonstrated that the PPSB plays a crucial role in plant metabolism by affecting glycolysis, the tricarboxylic acid cycle, and the biosynthesis of amino acids. We provide evidence of the crucial role of the PPSB in embryo, pollen, and root development and suggest that this pathway is an important link connecting primary metabolism with development.
authors.affiliation: Departament de Biologia Vegetal, Facultat de Farmàcia, Universitat de València, 46100 Burjassot, Valencia, Spain.
authors.forename: Borja
authors.initials: B
authors.lastname: Cascales-Miñana
authors.forename: Jesús
authors.initials: J
authors.lastname: Muñoz-Bertomeu
authors.forename: María
authors.initials: M
authors.lastname: Flores-Tornero
authors.forename: Armand Djoro
authors.initials: AD
authors.lastname: Anoman
authors.forename: José
authors.initials: J
authors.lastname: Pertusa
authors.forename: Manuel
authors.initials: M
authors.lastname: Alaiz
authors.forename: Sonia
authors.initials: S
authors.lastname: Osorio
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
authors.forename: Juan
authors.initials: J
authors.lastname: Segura
authors.forename: Roc
authors.initials: R
authors.lastname: Ros
mesh_terms: D000596:Amino Acids / Q000096:biosynthesis; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D053898:Biosynthetic Pathways / Q000235:genetics; D002952:Citric Acid Cycle / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D006019:Glycolysis / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D009154:Mutation; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011058:Pollen / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012694:Serine / Q000096:biosynthesis*
chemical_list: D000596:Amino Acids; D029681:Arabidopsis Proteins; D049452:Green Fluorescent Proteins; D012694:Serine; D010744:Phosphoric Monoester Hydrolases; C586768:PSP1 protein, Arabidopsis; C022394:phosphoserine phosphatase