The Phosphorylated Pathway of Serine Biosynthesis Is Essential Both for Male Gametophyte and Embryo Development and for Root Growth in Arabidopsis

• Published in: The Plant cell Vol. 25; no. 6; pp. 2084 - 2101
• Main Authors: Cascales-Miñana, Borja, Muñoz-Bertomeu, Jesús, Flores-Tornero, María, Anoman, Armand Djoro, Pertusa, José, Alaiz, Manuel, Osorio, Sonia, Fernie, Alisdair R., Segura, Juan, Ros, Roc
• Format: Journal Article Web Resource
• Language: English
• Published: United States American Society of Plant Biologists 01.06.2013
• Subjects: Aerial parts; Amino Acids; Amino Acids - biosynthesis; Anthers; Arabidopsis; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis protein; Arabidopsis Proteins; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biologie végétale (sciences végétales, sylviculture, mycologie...); Biosynthetic Pathways; Biosynthetic Pathways - genetics; Citric Acid Cycle; Citric Acid Cycle - genetics; Embryos; Gametophytes; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Glycolysis; Glycolysis - genetics; Green Fluorescent Proteins; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Immunoblotting; Life sciences; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Microspores; Mutation; Phosphoric Monoester Hydrolases; Phosphoric Monoester Hydrolases - genetics; Phosphoric Monoester Hydrolases - metabolism; Phosphorylation; Phytobiology (plant sciences, forestry, mycology...); Plant Roots; Plant Roots - genetics; Plant Roots - growth & development; Plant Roots - metabolism; Plants; Plants, Genetically Modified; Pollen; Pollen - genetics; Pollen - growth & development; Pollen - metabolism; PSP1 protein, Arabidopsis; Reverse Transcriptase Polymerase Chain Reaction; Sciences du vivant; Seeds; Seeds - genetics; Seeds - growth & development; Seeds - metabolism; Segregation; Serine; Serine - biosynthesis
• ISSN: 1040-4651; 1532-298X; 1532-298X
• DOI: 10.1105/tpc.113.112359

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.