MOTHER OF FT AND TFL1 regulates seed germination through a negative feedback loop modulating ABA signaling in Arabidopsis.
Abscisic acid (ABA) and gibberellin (GA) are two antagonistic phytohormones that regulate seed germination in response to biotic and abiotic environmental stresses. We demonstrate here that MOTHER OF FT AND TFL1 (MFT), which encodes a phosphatidylethanolamine-binding protein, regulates seed germination via the ABA and GA signaling pathways in Arabidopsis thaliana. MFT is specifically induced in the radical-hypocotyl transition zone of the embryo in response to ABA, and mft loss-of-function mutants show hypersensitivity to ABA in seed germination. In germinating seeds, MFT expression is directly regulated by ABA-INSENSITIVE3 (ABI3) and ABI5, two key transcription factors in ABA signaling pathway. MFT is also upregulated by DELLA proteins in the GA signaling pathway. MFT in turn provides negative feedback regulation of ABA signaling by directly repressing ABI5. We conclude that during seed germination, MFT promotes embryo growth by constituting a negative feedback loop in the ABA signaling pathway.
Xi
Wanyan
W
Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 117543, Singapore.
Liu
Chang
C
Hou
Xingliang
X
Yu
Hao
H
D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000378:metabolism; D002352:Carrier Proteins; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018525:Germination; D005875:Gibberellins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D018749:RNA, Plant / Q000235:genetics; D012639:Seeds / Q000254:growth & development*; D014157:Transcription Factors
C091601:ABI3 protein, Arabidopsis; C409743:ABI5 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D002352:Carrier Proteins; D005875:Gibberellins; D047908:Intracellular Signaling Peptides and Proteins; C492735:MFT protein, Arabidopsis; D018749:RNA, Plant; D014157:Transcription Factors; D000040:Abscisic Acid