At5PTase13 modulates cotyledon vein development through regulating auxin homeostasis.
Phosphatidylinositol signaling pathway and the relevant metabolites are known to be critical to the modulation of different aspects of plant growth, development, and stress responses. Inositol polyphosphate 5-phosphatase is a key enzyme involved in phosphatidylinositol metabolism and is encoded by an At5PTase gene family in Arabidopsis thaliana. A previous study shows that At5PTase11 mediates cotyledon vascular development probably through the regulation of intracellular calcium levels. In this study, we provide evidence that At5PTase13 modulates the development of cotyledon veins through its regulation of auxin homeostasis. A T-DNA insertional knockout mutant, At5pt13-1, showed a defect in development of the cotyledon vein, which was rescued completely by exogenous auxin and in part by brassinolide, a steroid hormone. Furthermore, the mutant had reduced auxin content and altered auxin accumulation in seedlings revealed by the DR5:beta-glucuronidase fusion construct in seedlings. In addition, microarray analysis shows that the transcription of key genes responsible for auxin biosynthesis and transport was altered in At5pt13-1. The At5pt13-1 mutant was also less sensitive to auxin inhibition of root elongation. These results suggest that At5PTase13 regulates the homeostasis of auxin, a key hormone controlling vascular development in plants.
Lin
Wen-Hui
WH
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032 Shanghai, People's Republic of China.
Wang
Yuan
Y
Mueller-Roeber
Bernd
B
Brearley
Charles A
CA
Xu
Zhi-Hong
ZH
Xue
Hong-Wei
HW
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D018548:Cotyledon / Q000254:growth & development / Q000378:metabolism; D018744:DNA, Plant / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D006706:Homeostasis; D007210:Indoleacetic Acids / Q000378:metabolism*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010744:Phosphoric Monoester Hydrolases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D007210:Indoleacetic Acids; C499855:5PTase13 protein, Arabidopsis; D010744:Phosphoric Monoester Hydrolases