title: Apple (Malus domestica) MdERF2 negatively affects ethylene biosynthesis during fruit ripening by suppressing MdACS1 transcription.
abstract: Ripening in climacteric fruit requires the gaseous phytohormone ethylene. Although ethylene signaling has been well studied, knowledge of the transcriptional regulation of ethylene biosynthesis is still limited. Here we show that an apple (Malus domestica) ethylene response factor, MdERF2, negatively affects ethylene biosynthesis and fruit ripening by suppressing the transcription of MdACS1, a gene that is critical for biosynthesis of ripening-related ethylene. Expression of MdERF2 was suppressed by ethylene during ripening of apple fruit, and we observed that MdERF2 bound to the promoter of MdACS1 and directly suppressed its transcription. Moreover, MdERF2 suppressed the activity of the promoter of MdERF3, a transcription factor that we found to bind to the MdACS1 promoter, thereby increasing MdACS1 transcription. We determined that the MdERF2 and MdERF3 proteins directly interact, and this interaction suppresses the binding of MdERF3 to the MdACS1 promoter. Moreover, apple fruit with transiently downregulated MdERF2 expression showed higher ethylene production and faster ripening. Our results indicate that MdERF2 negatively affects ethylene biosynthesis and fruit ripening in apple by suppressing the transcription of MdACS1 via multiple mechanisms, thereby acting as an antagonist of positive ripening regulators. Our findings offer a deep understanding of the transcriptional regulation of ethylene biosynthesis during climacteric fruit ripening.
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Li
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Zhongyu
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Lichao
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Tan
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wei
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Yuan
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Tianlai
authors.initials: T
authors.lastname: Li
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Aide
authors.initials: A
authors.lastname: Wang
mesh_terms: D005030:Ethylenes / Q000378:metabolism; D005638:Fruit / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D027845:Malus / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D005030:Ethylenes; D010940:Plant Proteins; C036216:ethylene
keywords: 
  ACS
  ; apple; ethylene; ethylene response factor; fruit ripening; protein interaction