Membrane-associated transcription factor peptidase, site-2 protease, antagonizes ABA signaling in Arabidopsis.
Abscisic acid plays important roles in maintaining seed dormancy while gibberellins (GA) and other phytohormones antagonize ABA to promote germination. However, how ABA signaling is desensitized during the transition from dormancy to germination is still poorly understood. We functionally characterized the role of membrane-associated transcription factor peptidase, site-2 protease (S2P), in ABA signaling during seed germination in Arabidopsis. Genetic analysis showed that loss-of-function of S2P conferred high ABA sensitivity during seed germination, and expression of the activated form of membrane-associated transcription factor bZIP17, in which the transmembrane domain and endoplasmic reticulum (ER) lumen-facing C-terminus were deleted, in the S2P mutant rescued its ABA-sensitive phenotype. MYC and green fluorescent protein (GFP)-tagged bZIP17 were processed and translocated from the ER to the nucleus in response to ABA treatment. Furthermore, genes encoding negative regulators of ABA signaling, such as the transcription factor ATHB7 and its target genes HAB1, HAB2, HAI1 and AHG3, were up-regulated in seeds of the wild-type upon ABA treatment; this up-regulation was impaired in seeds of S2P mutants. Our results suggest that S2P desensitizes ABA signaling during seed germination through regulating the activation of the membrane-associated transcription factor bZIP17 and therefore controlling the expression level of genes encoding negative regulators of ABA signaling.
State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
Shun-Fan
SF
Zhou
State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
Le
L
Sun
Physiological Botany, Uppsala BioCenter, Uppsala University, Almas Allé 5, 75651, Uppsala, Sweden.|Linnean Centre for Plant Biology, Uppsala, Sweden.
Ana Elisa
AE
Valdés
Physiological Botany, Uppsala BioCenter, Uppsala University, Almas Allé 5, 75651, Uppsala, Sweden.|Linnean Centre for Plant Biology, Uppsala, Sweden.
Peter
P
Engström
State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
Ze-Ting
ZT
Song
State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
Sun-Jie
SJ
Lu
State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
Jian-Xiang
JX
Liu
D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000378:metabolism; D001692:Biological Transport; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018525:Germination / Q000235:genetics; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism*; D063245:Plant Development / Q000235:genetics; D057445:Plant Dormancy / Q000235:genetics; D010937:Plant Growth Regulators / Q000378:metabolism; D012639:Seeds / Q000254:growth & development* / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*; D015854:Up-Regulation
D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D008565:Membrane Proteins; D010937:Plant Growth Regulators; D014157:Transcription Factors; C525259:bZIP17 protein, Arabidopsis; D000040:Abscisic Acid; D010447:Peptide Hydrolases
ABA response; Arabidopsis; membrane-associated transcription factor; regulated intramembrane proteolysis; seed germination; site-2 peptidase (S2P)