Expression of the AtGH3a gene, an Arabidopsis homologue of the soybean GH3 gene, is regulated by phytochrome B.
Light is one of the most crucial environmental cues for plants. Phytochrome, one of the major photoreceptors of plants, regulates expression of many genes. We screened for Arabidopsis promoter trap lines that exhibited light-dependent reporter gene expression. Molecular analysis of one such line revealed that a reporter gene was inserted near an Arabidopsis homologue of the soybean GH3 gene, AtGH3a. We performed RNA gel blot analysis to further characterize the response of the AtGH3a gene to light. In response to the end-of-day far-red light treatment, the expression increased substantially. Analysis of the phyB-deficient mutant indicated that this light response is under the control of phytochrome B. The expression was also induced by exogenous auxin. Furthermore, the light response was substantially reduced in the auxin-related axr2 mutant. Taken together, it is suggested that phytochrome B regulates the expression of genes by altering the levels of auxin.
Tanaka
Shin-ichiro
S
Department of Botany, Graduate School of Science, Kyoto University, Sakyo-Ku, Kyoto, 606-8502, Japan.
Mochizuki
Nobuyoshi
N
Nagatani
Akira
A
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D029681:Arabidopsis Proteins; D005786:Gene Expression Regulation / Q000187:drug effects / Q000528:radiation effects; D007210:Indoleacetic Acids / Q000494:pharmacology; D008027:Light; D009154:Mutation; D010786:Photoreceptor Cells; D010834:Phytochrome / Q000235:genetics / Q000378:metabolism*; D051939:Phytochrome B; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D030262:Soybean Proteins; D013025:Glycine max / Q000235:genetics*; D014157:Transcription Factors
D029681:Arabidopsis Proteins; C425524:DFL1 protein, Arabidopsis; C070797:GH3 protein, soybean; D007210:Indoleacetic Acids; C497952:PHYB protein, Arabidopsis; D010937:Plant Growth Regulators; D010940:Plant Proteins; D030262:Soybean Proteins; D014157:Transcription Factors; D010834:Phytochrome; D051939:Phytochrome B; C030737:indoleacetic acid