A membrane-associated NAC transcription factor regulates salt-responsive flowering via FLOWERING LOCUS T in Arabidopsis.
The plant-specific NAC (NAM, ATAF1/2, CUC2) transcription factors play regulatory roles in diverse developmental processes and stress responses. Notably, a subset of the NAC members, collectively designated NTLs, is membrane-associated, suggesting that membrane-mediated regulation would be an important molecular scheme functioning in rapid transcriptional responses to external stimuli. Here, we examined the physiological role of a salt-responsive NTL, NTL8, by molecular genetic and transgenic approaches. NTL8 is expressed as a membrane-associated, dormant form and subsequently processed into a transcriptionally active, nuclear form. Transgenic plants overproducing an active NTL8 form exhibited delayed flowering as well as reduced growth with small curled leaves. Accordingly, expression of FLOWERING LOCUS T (FT) and its downstream genes was significantly reduced in the transgenic plants. Furthermore, FT was significantly repressed by high salt. We therefore propose that NTL8 mediates salt-responsive flowering via FT in Arabidopsis.
Kim
Sang-Gyu
SG
Molecular Signaling Laboratory, Department of Chemistry, Seoul National University, Seoul 151-742, Korea.
Kim
Sun-Young
SY
Park
Chung-Mo
CM
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D035264:Flowers / Q000187:drug effects* / Q000502:physiology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D008969:Molecular Sequence Data; D010641:Phenotype; D030821:Plants, Genetically Modified; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*
D029681:Arabidopsis Proteins; C418905:FT protein, Arabidopsis; C523576:NTL8 protein, Arabidopsis; D012333:RNA, Messenger; D014157:Transcription Factors; D012965:Sodium Chloride