Identification by Large-Scale Screening of Phytochrome-Regulated Genes in Etiolated Seedlings of Arabidopsis Using a Fluorescent Differential Display Technique

Abstract

Phytochrome A (PhyA)-regulated genes in 6-d-old etiolated seedlings of Arabidopsis Landsberg erecta were identified by fluorescent differential display. To screen for PhyA-regulated genes, mRNA fingerprints of the wild type and the phyA-201 mutant were compared from samples prepared 4 h after far-red light irradiation. Approximately 30,000 bands of cDNA were displayed by fluorescent differential display, and 24 differentially expressed bands were observed. Sequence analysis revealed that they represent 20 distinct genes. Among them, 15 genes were confirmed as PhyA regulated by northern-blot (or reverse transcription-polymerase chain reaction) analysis. Thirteen up-regulated genes included 12 known genes that encode nine photosynthetic proteins, two enzymes involved in the biosynthesis of chlorophyll, one DNA damage repair/toleration-related protein, and one unknown gene. Two down-regulated genes were identified as encoding a xyloglucan endotransglycosylase-related protein and a novel member of the ASK protein kinase family. In the phyA-201 mutant and the phyA-201phyB-1 double mutant, expression of all of these genes was photoreversibly up- or down-regulated by type II phytochromes. The results indicate that modes of photoperception differ between PhyA and PhyB, but that both types of phytochromes have overlapping effects on the photoregulation of gene expression.

HYPERSENSITIVE TO RED AND BLUE 1, a ZZ-Type Zinc Finger Protein, Regulates Phytochrome B–Mediated Red and Cryptochrome-Mediated Blue Light Responses

“…We also examined the expression of XTR7, which encodes a xyloglucan endotransglycosylase and is likely involved in cell wall polymer hydrolysis and cell wall extension. The expression of XTR7 was downregulated by red and far-red light, as shown previously (Kuno et al, 2000), and also by blue light in this study (Figure 4B). No dramatic change was detected for the light downregulation of XTR7 expression in either hrb1 or pif4 ( Figure 4C).…”

Multiple transcription-factor genes are early targets of phytochrome A signaling

“…Although a considerable number of studies have examined expression patterns of a limited number of individual genes underlying these responses (2)(3)(4), a global analysis of photoregulated genes has been lacking. The availability of microarray-based expression profiling technology now permits such an analysis (5) and thus the assembly of an integrated picture of these expression patterns.…”

Overexpression of a Mutant Basic Helix-Loop-Helix Protein HFR1, HFR1-ΔN105, Activates a Branch Pathway of Light Signaling in Arabidopsis

“…Multiple genes encoding transcription factors are up-or down-regulated by light within 1 h after irradiation (Tepperman et al, 2001). Such changes in transcription factors are presumed to regulate the orchestrated expression of various downstream light-regulated genes, including CAB, CHS, XTR7, and DRT112 (Kuno et al, 2000;Ma et al, 2001).A number of photoreceptors controlling lightdependent development, including red (R) and farred (FR) light-absorbing phytochromes, blue (B) light receptors, cryptochromes, and phototropins have been characterized (Furuya, 1993;Lin, 2000). Among these, the phytochromes are the best characterized.…”