title: The over-expression of a chrysanthemum WRKY transcription factor enhances aphid resistance.
abstract: Members of the large WRKY transcription factor family are responsible for the regulation of plant growth, development and the stress response. Here, five WRKY members were isolated from chrysanthemum. They each contained a single WRKY domain and a C2H2 zinc finger motif, so were classified into group II. Transient expression experiments demonstrated that all five were expressed in the nucleus, although CmWRKY42 was also expressed in the cytoplasm. When expressed heterologously in yeast, the products of CmWRKY22 and CmWRKY48 exhibited transactivation activity, while those of CmWRKY21, CmWRKY40 and CmWRKY42 did not. The transcription of the five CmWRKY genes was profiled when the plants were challenged with a variety of abiotic and biotic stress agents, as well as being treated with various phytohormones. CmWRKY21 proved to be markedly induced by salinity stress, and suppressed by high temperature exposure; CmWRKY22 was induced by high temperature exposure; CmWRKY40 was highly induced by salinity stress, and treatment with either abscisic acid (ABA) or methyl jasmonate (MeJA); CmWRKY42 was up-regulated by salinity stress, low temperature, ABA and MeJA treatment and aphid infestation; CmWRKY48 was induced by drought stress, ABA and MeJA treatment and aphid infestation. The function of CmWRKY48 was further investigated by over-expressing it transgenically. The constitutive expression of this transcription factor inhibited the aphids' population growth capacity, suggesting that it may represent an important component of the plant's defense machinery against aphids.
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Peiling
authors.initials: P
authors.lastname: Li
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Aiping
authors.initials: A
authors.lastname: Song
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Gao
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jiafu
authors.initials: J
authors.lastname: Jiang
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Sumei
authors.initials: S
authors.lastname: Chen
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Fang
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: chenfd@njau.edu.cn.
authors.forename: Fadi
authors.initials: F
authors.lastname: Chen
mesh_terms: D000818:Animals; D001042:Aphids; D031202:Chrysanthemum / Q000235:genetics / Q000378:metabolism / Q000469:parasitology; D060467:Disease Resistance / Q000235:genetics*; D010935:Plant Diseases / Q000469:parasitology*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors
keywords: Aphid; Chrysanthemum; Expression analysis; WRKY