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Abstract
In plants, phenylalanine biosynthesis occurs via two compartmentally separated pathways. Overexpression of petunia chorismate mutase 2 (PhCM2), which catalyzes the committed step of the cytosolic pathway, increased flux in cytosolic phenylalanine biosynthesis, but paradoxically decreased the overall levels of phenylalanine and phenylalanine-derived volatiles. Concomitantly, the levels of auxins, including indole-3-acetic acid and its precursor indole-3-pyruvic acid, were elevated. Biochemical and genetic analyses revealed the existence of metabolic crosstalk between the cytosolic phenylalanine biosynthesis and tryptophan-dependent auxin biosynthesis mediated by an aminotransferase that uses a cytosolic phenylalanine biosynthetic pathway intermediate, phenylpyruvate, as an amino acceptor for auxin formation.
In plants, the cytosolic phenylalanine biosynthetic intermediate phenylpyruvate can serve as an amino acceptor in tryptophan-dependent auxin biosynthesis, thus facilitating crosstalk between these two distinct primary metabolic pathways.
Details
; Qian Yichun 2 ; Guo Longyun 3 ; Maoz Itay 1 ; Xing-Qi, Huang 1 ; Garcia, Alekzander S 4 ; Louie, Gordon 5 ; Bowman, Marianne E 5 ; Noel, Joseph P 6
; Morgan, John A 7
; Dudareva Natalia 8
1 Purdue University, Department of Biochemistry, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197)
2 Purdue University, Department of Horticulture and Landscape Architecture, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197); New York University, Center for Genomics and Systems Biology, Department of Biology, New York, USA (GRID:grid.137628.9) (ISNI:0000 0004 1936 8753)
3 Purdue University, Department of Biochemistry, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197); WuXi Biologics, Wuxi, China (GRID:grid.169077.e)
4 Purdue University, Department of Biochemistry, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197); University of Illinois at Urbana-Champaign, Department of Chemistry, Urbana, USA (GRID:grid.35403.31) (ISNI:0000 0004 1936 9991)
5 Jack H Skirball Center for Chemical Biology and Proteomics, Salk Institute for Biological Studies, La Jolla, USA (GRID:grid.250671.7) (ISNI:0000 0001 0662 7144)
6 Jack H Skirball Center for Chemical Biology and Proteomics, Salk Institute for Biological Studies, La Jolla, USA (GRID:grid.250671.7) (ISNI:0000 0001 0662 7144); Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, USA (GRID:grid.250671.7) (ISNI:0000 0001 0662 7144)
7 Purdue University, Department of Biochemistry, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197); Purdue University, Davidson School of Chemical Engineering, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197)
8 Purdue University, Department of Biochemistry, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197); Purdue University, Department of Horticulture and Landscape Architecture, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197); Purdue University, Purdue Center for Plant Biology, West Lafayette, USA (GRID:grid.169077.e) (ISNI:0000 0004 1937 2197)