Deficiency in the Phosphorylated Pathway of Serine Biosynthesis Perturbs Sulfur Assimilation.

Although the plant Phosphorylated Pathway of l-Ser Biosynthesis (PPSB) is essential for embryo and pollen development, and for root growth, its metabolic implications have not been fully investigated. A transcriptomics analysis of Arabidopsis (Arabidopsis thaliana) PPSB-deficient mutants at night, when PPSB activity is thought to be more important, suggested interaction with the sulfate assimilation process. Because sulfate assimilation occurs mainly in the light, we also investigated it in PPSB-deficient lines in the day. Key genes in the sulfate starvation response, such as the adenosine 5′phosphosulfate reductase genes, along with sulfate transporters, especially those involved in sulfat…