Regulation of Arabidopsis thaliana Ku genes at different developmental stages under heat stress.
Ku, a heterodimeric protein consisting of 70- and 80-kDa subunits, is involved in many cellular processes, such as DNA replication, cell cycle regulation and heat shock response. Moreover, the expression of Arabidopsis thaliana Ku genes (AtKu) is modulated by certain plant hormones through several signal transduction pathways. This study investigated how AtKu are regulated by heat stress. AtKu expression in 3-week-old young seedlings was down-regulated by heat stress in a time-dependent manner, as examined using real-time quantitative PCR, GUS reporter systems, and western blotting analysis. Additionally, the heat-induced repression of AtKu was mediated through the abscisic acid (ABA) biosynthetic pathway, as shown by the reversal of AtKu suppression in the ABA biosynthesis mutant, aba3, and by an increase in the ABA level as analyzed by reverse-phase high performance liquid chromatography. Heat stress-induced regulation of AtKu repression also involved ethylene signaling, DNA repair pathways, and fatty acid synthesis. Furthermore, AtKu expression was repressed in stems, rosette leaves, and cauline leaves in 4-5-week-old plants under heat stress, whereas it remained unchanged in roots and primary inflorescence, indicating that heat differentially modulated AtKu expression in distinct tissues of Arabidopsis.
Liu
Pei Feng
PF
Department of Life Sciences and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsin Chu, Taiwan 30013, ROC.
Wang
Yung Kai
YK
Chang
Wen Chi
WC
Chang
Hwan You
HY
Pan
Rong Long
RL
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D004265:DNA Helicases / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D015536:Down-Regulation; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006358:Hot Temperature; D009154:Mutation; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013466:Sulfurtransferases / Q000235:genetics; D014018:Tissue Distribution
D029681:Arabidopsis Proteins; D017931:DNA Primers; D018744:DNA, Plant; D004268:DNA-Binding Proteins; C463462:KU70 protein, Arabidopsis; C440026:ABA3 protein, Arabidopsis; D013466:Sulfurtransferases; D004265:DNA Helicases; C469228:Ku80 protein, Arabidopsis