FIERY1 regulates light-mediated repression of cell elongation and flowering time via its 3'(2'),5'-bisphosphate nucleotidase activity

• Published in: The Plant journal : for cell and molecular biology 2009-04, Vol.58 (2), p.208-219
• Main Authors: Kim, Byung-Hoon, von Arnim, Albrecht G
• Format: Article
• Language: English
• Subjects: 3'-phosphoadenosine 5'-phosphate; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological and medical sciences; Botany; Cell differentiation, maturation, development, hematopoiesis; Cell Enlargement; Cell physiology; Cellular biology; Chlorophyll - metabolism; exoribonuclease; flowering; Flowers & plants; Flowers - genetics; Flowers - growth & development; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genes, Plant; Genetic Complementation Test; Light; Molecular and cellular biology; Mutagenesis, Insertional; Mutation; Nucleotidases - genetics; Nucleotidases - metabolism; Phosphoric Monoester Hydrolases; photomorphogenesis; Phytochrome B - metabolism; Plants, Genetically Modified - enzymology; Plants, Genetically Modified - genetics; Plants, Genetically Modified - growth & development; RNA interference; RNA, Plant - genetics; sulfonation
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313X.2008.03770.x

Light is one of the most important environmental factors that regulate plant development. Here we report that a mutation in the Arabidopsis FIERY1 gene (FRY1) caused a shortened hypocotyl and shorter petioles, most dramatically under low-intensity red light and less pronounced under far-red and blue-light conditions. Furthermore, the fry1 mutant flowered late, probably due to a reduced level of FLOWERING LOCUS T (FT) transcript. However, although the transcript level of FRY1 was light-regulated, the chlorophyll level and the expression of typical light-regulated genes were not affected in the fry1 mutant. FRY1 is known as a regulator of abiotic stress responses, and its protein product has dual enzymatic activity comprising inositol polyphosphate-1-phosphatase and 3'(2'),5'-bisphosphate nucleotidase activity. Genetic complementation data obtained using cDNA of the FRY1 paralog AHL (Arabidopsis HAL2-like) and the similar phenotype of an xrn2/xrn3 double mutant suggest that FRY1 attenuates light responses via its 3'(2'),5'-bisphosphate nucleotidase activity rather than its inositol polyphosphate-1-phosphatase activity. We discuss the relationship between the FRY1-associated nucleotidase activity, a step in the pathway for sulfur metabolism and utilization, and the Arabidopsis light response.