The membrane-tethered transcription factor ANAC089 serves as redox-dependent suppressor of stromal ascorbate peroxidase gene expression.

摘要: The stromal ascorbate peroxidase (sAPX) functions as central element of the chloroplast antioxidant defense system. Its expression is under retrograde control signals including redox- and reactive oxygen species-linked cues. sAPX promoter Arabidopsis thaliana was dissected in transient reporter assays using mesophyll protoplasts. study revealed regulatory elements up to -1868 upstream start codon. By yeast-one-hybrid screening, transcription factor ANAC089 identified bind fragment 2 (-1262 -1646 bp translational initiation). Upon mutation cis-acting CACG, binding abolished. Expression a fused fluorescent protein version comparison with known endomembrane markers localized trans-Golgi network ER. released upon treatment reducing agents targeted nucleus. Transactivation wild type mutated versions showed partial suppression expression. data indicate that negative loop, lowering if cell encounters highly condition. This conclusion supported by reciprocal transcript accumulation during acclimation low, normal, high light conditions.