Generation of phytate-free seeds in Arabidopsis through disruption of inositol polyphosphate kinases.
Phytate (inositol hexakisphosphate, IP6) is a regulator of intracellular signaling, a highly abundant animal antinutrient, and a phosphate store in plant seeds. Here, we report a requirement for inositol polyphosphate kinases, AtIPK1 and AtIPK2beta, for the later steps of phytate synthesis in Arabidopsis thaliana. Coincident disruption of these kinases nearly ablates seed phytate without accumulation of phytate precursors, increases seed-free phosphate by 10-fold, and has normal seed yield. Additionally, we find a requirement for inositol tetrakisphosphate (IP4)/inositol pentakisphosphate (IP5) 2-kinase activity in phosphate sensing and root hair elongation. Our results define a commercially viable strategy for the genetic engineering of phytate-free grain and provide insights into the role of inositol polyphosphate kinases in phosphate signaling biology.
Stevenson-Paulik
Jill
J
Department of Pharmacology and Cancer Biology, Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA.
Bastidas
Robert J
RJ
Chiou
Shean-Tai
ST
Frye
Roy A
RA
York
John D
JD
D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D017343:Genes, Plant; D005818:Genetic Engineering; D009154:Mutation; D010641:Phenotype; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D010833:Phytic Acid / Q000096:biosynthesis / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism; D015398:Signal Transduction
D010833:Phytic Acid; D017853:Phosphotransferases (Alcohol Group Acceptor)