title: Proteomic and gene expression analyses during bolting-related leaf color change in Brassica rapa.
abstract: Bolting and flowering are key processes during the growth and development of Chinese cabbage (Brassica rapa L. ssp pekinensis). Understanding the molecular mechanisms underlying bolting and flowering is of significance for improving production of the vegetable. A leaf-color change from bright green to gray-green has been observed following differentiation of the flowering stem and before bolting in the vegetable, and is considered to be a signal for bolting. Proteomics in meristem tissues of an inbred line (C30) were analyzed by two-dimensional electrophoresis during the transition period. We found that some proteins were specifically expressed while others were differentially expressed. Among these, 17 proteins were specifically expressed before the color change, 18 were specifically expressed after the color change, 21 were downregulated during the color change, and 29 were upregulated. Mass spectrometric analysis (MALDI-TOF-TOF/MS) was used to analyze 17 protein spots, and four proteins (subunit E1 of vacuolar-type H+ transporter ATPase, the large subunit of Rubicon, S-adenosylmethionine synthetase, and tubulin α-2) were identified. qPCR analysis was conducted to quantify the expression of genes encoding these proteins during the transitional period. The expression of BrVHA-E1, BrSAMS, BrrbcL, and BrTUA6 was significantly different before and after the leaf-color change, suggesting that these genes might be involved in regulating flower differentiation and bolting.
authors.affiliation: College of Horticulture, Northeast Agricultural University, Harbin, China zhangyaowei@neau.edu.cn.|Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Ministry of Agriculture, Harbin, China zhangyaowei@neau.edu.cn.
authors.forename: Y W
authors.initials: YW
authors.lastname: Zhang
authors.affiliation: College of Horticulture, Northeast Agricultural University, Harbin, China.
authors.forename: M H
authors.initials: MH
authors.lastname: Guo
authors.affiliation: College of Horticulture, Northeast Agricultural University, Harbin, China.
authors.forename: X B
authors.initials: XB
authors.lastname: Tang
authors.affiliation: College of Horticulture, Northeast Agricultural University, Harbin, China.
authors.forename: D
authors.initials: D
authors.lastname: Jin
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Fang
mesh_terms: D029741:Brassica rapa / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D010858:Pigmentation; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D010940:Plant Proteins; D020543:Proteome