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The MADS box gene, FOREVER YOUNG FLOWER , acts as a repressor controlling floral organ senescence and abscission in Arabidopsis
Author(s) -
Chen MingKun,
Hsu WeiHan,
Lee PeiFang,
Thiruvengadam Muthu,
Chen HongIe,
Yang ChangHsien
Publication year - 2011
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2011.04677.x
Subject(s) - mads box , abscission , senescence , repressor , arabidopsis , biology , gene , botany , microbiology and biotechnology , transcription factor , genetics , mutant
Summary The ectopic expression of a MADS box gene FOREVER YOUNG FLOWER ( FYF ) caused a significant delay of senescence and a deficiency of abscission in flowers of transgenic Arabidopsis. The defect in floral abscission was found to be due to a deficiency in the timing of cell separation of the abscission zone cells. Down‐regulation of INFLORESCENCE DEFICIENT IN ABSCISSION ( IDA ) may contribute to the delay of the floral abscission in 35S:FYF flowers. FYF was found to be highly expressed in young flowers prior to pollination and was significantly decreased after pollination, a pattern that correlated with its function. Ethylene insensitivity in senescence/abscission and the down‐regulation of ETHYLENE RESPONSE DNA‐BINDING FACTOR 1 ( EDF1 ) and EDF2 , downstream genes in the ethylene response, in 35S:FYF Arabidopsis suggested a role for FYF in regulating senescence/abscission by suppressing the ethylene response. This role was further supported by the fact that 35S:FYF enhanced the delay of flower senescence/abscission in ethylene response 1 ( etr1 ), ethylene‐insensitive 2 ( ein2 ) and constitutive triple response 1 ( ctr1 ) mutants, which have defects in upstream genes of the ethylene signaling pathway. The presence of a repressor domain in the C‐terminus of FYF and the enhancement of the delay of senescence/abscission in FYF+SRDX (containing a suppression motif) transgenic plants suggested that FYF acts as a repressor. Indeed, in FYF‐DR+VP16 transgenic dominant‐negative mutant plants, in which FYF was converted to a potent activator by fusion to a VP16‐AD motif, the senescence/abscission of the flower organs was significantly promoted, and the expression of BOP2 , IDA and EDF1 / 2 was up‐regulated. Our data suggest a role for FYF in controlling floral senescence/abscission by repressing ethylene responses and regulating the expression of BOP2 and IDA in Arabidopsis.