Moon, Jennifer , Zhu, Ling , Shen, Hui , Huq, Enamul .
PIF1 directly regulates chlorophyll biosynthesis to optimize the greening process in Arabidopsis.
Plants depend on light signals to modulate many aspects of their development and to optimize their photosynthetic capacity. Phytochromes (phys), a family of photoreceptors, initiate a signal transduction pathway that alters expression of a large number of genes to induce these responses. phyA and phyB bind members of a bHLH family of transcription factors called phytochrome interacting factors (PIFs). PIF1 negatively regulates chlorophyll biosynthesis and seed germination in the dark, and light-induced destabilization of PIF1 relieves this negative regulation to promote photomorphogenesis. Here we report that PIF1 regulates expression of a small set of genes in the dark, majority of which are involved in controlling the chlorophyll pathway. We demonstrate that PIF1 directly binds to a G-box (CACGTG) DNA sequence element present in the promoters of PORC and FeChII genes. Moreover, in a transient assay using dark-grown Arabidopsis seedlings, PIF1 activates transcription of PORC in a G-box dependent manner. These data strongly suggest that PIF1 directly regulates a subset of genes involved in chlorophyll biosynthesis to optimize the greening process in Arabidopsis.
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1 - University of Texas at Austin, Molecular Cell and Developmental Biology
2 - University of Texas at Austin, Molecular Cell and Developmental Biology, 1 University Station, A6700, Austin, TX, 78712, USA
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM