Regulation of Arabidopsis thaliana plasma membrane glucose-responsive regulator (AtPGR) expression by A. thaliana storekeeper-like transcription factor, AtSTKL, modulates glucose response in Arabidopsis

Arabidopsis Basic Helix-Loop-Helix 34 (bHLH34) Is Involved in Glucose Signaling through Binding to a GAGA Cis-Element

“…Recently, we demonstrated that the promoter sequences between nucleotide (nt) positions -999 and -456 of the AtPGR gene modulate transcription expression of the gene during Glc treatment ( Chung et al, 2016 ). To identify transcription factors involved in the regulation of AtPGR , we performed yeast one-hybrid screening of a cDNA library of Arabidopsis ( Chung et al, 2016 ).…”

“…Recently, we demonstrated that the promoter sequences between nucleotide (nt) positions -999 and -456 of the AtPGR gene modulate transcription expression of the gene during Glc treatment ( Chung et al, 2016 ). To identify transcription factors involved in the regulation of AtPGR , we performed yeast one-hybrid screening of a cDNA library of Arabidopsis ( Chung et al, 2016 ). The yeast one-hybrid method involved in the X -galactosidase (Gal) filter assay was used to isolate transcription factor candidates that bind to P999-binding site (between positions -999 and -456 nt) in the upstream region of AtPGR ( Figure 1A and Supplementary Figure S1A ).…”

“…The AtPGR promoter 999 (P999)-GUS construct was generated as described previously ( Chung et al, 2016 ), and the overexpression of bHLH34 in the P999-GUS transgenic lines was achieved as described in Supplementary Materials and Methods.…”

“…A number of cis -regulatory elements responsible for the sugar-mediated gene modulation have been identified ( Rolland et al, 2006 ), including G-box ( Giuliano et al, 1988 ), W-box ( Pla et al, 1993 ), SP8 motif ( Ishiguro and Nakamura, 1994 ), sugar-response element (SURE) ( Grierson et al, 1994 ), GC-box ( Lu et al, 1998 ), osamy element ( Lu et al, 2002 ), and the GCCT element ( Chung et al, 2016 ). Recently, we reported that the A. thaliana Storekeeper-like 1 and 2 (AtSTKL1 and AtSTKL2) bind to the GCCT element in the AtPGR promoter region and suppress the gene activation ( Chung et al, 2016 ). Overexpression of AtPGR modulates the induction of Glc and 2-deoxyglucose insensitivity under stress.…”

“…AtSTKL homologs are capable of modulating the Glc response through the alteration of AtPGR expression. AtSTKL -overexpressing transgenic plants enhance the sensitivity to Glc in comparison with the wild type (WT), whereas atstkl s antisense plants show decreased sensitivity even with the high levels of Glc during cotyledon greening, indicating that AtSTKL play a significant role in Glc or Glc-mediated signaling pathways in Arabidopsis ( Chung et al, 2016 ).…”