title: Transcriptomic and hormone analyses reveal mechanisms underlying petal elongation in Chrysanthemum morifolium 'Jinba'.
abstract: Auxin regulates chrysanthemum petal elongation by promoting cell elongation. Transcriptomic analysis shows that auxin signal transduction may connect with other transcription factors by TCPs to regulate chrysanthemum petal elongation. As an ornamental species, Chrysanthemum morifolium has high ornamental and economic value. Petal size is the primary factor that influences the ornamental value of chrysanthemum, but the mechanism underlying the development of C. morifolium petals remains unclear. In our study, we tracked the growth of petals and found that the basal region of 'Jinba' petals showed a higher elongation rate, exhibiting rapid cell elongation during petal growth. During petal elongation growth, auxin was demonstrated to promote cell elongation and an increase in cell numbers in the petal basal region. To further study the molecular mechanisms underlying petal growth, the RNA-seq (high-throughput cDNA sequencing) technique was employed. Four cDNA libraries were assembled from petals in the budding, bud breaking, early blooming and full blooming stages of 'Jinba' flower development. Analysis of differentially expressed genes (DEGs) showed that auxin was the most important regulator in controlling petal growth. The TEOSINTEBRANCHED 1, CYCLOIDEA and PCF transcription factor genes (TCPs), basic helix-loop-helix-encoding gene (bHLH), glutaredoxin-C (GRXC) and other zinc finger protein genes exhibited obvious up-regulation and might have significant effects on the growth of 'Jinba' petals. Given the interaction between these genes in Arabidopsis thaliana, we speculated that auxin signal transduction might exhibit a close relationship with transcription factors through TCPs. In summary, we present the first comprehensive transcriptomic and hormone analyses of C. morifolium petals. The results offer direction in identifying the mechanism underlying the development of chrysanthemum petals in the elongated phase and have great significance in improving the ornamental characteristics of C. morifolium via molecular breeding.
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Haibin
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Lian
authors.initials: L
authors.lastname: Ding
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: Feng
authors.initials: F
authors.lastname: Shen
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. chenfd@njau.edu.cn.|Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology & Equipment, Nanjing, 210095, China. chenfd@njau.edu.cn.
authors.forename: Fadi
authors.identifier: http://orcid.org/0000-0002-7475-4150
authors.initials: F
authors.lastname: Chen
mesh_terms: D001593:Benzyl Compounds / Q000494:pharmacology; D031202:Chrysanthemum / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D003583:Cytokinins / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology; D010937:Plant Growth Regulators / Q000235:genetics / Q000378:metabolism*; D011687:Purines / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics; D059467:Transcriptome
chemical_list: D001593:Benzyl Compounds; D003583:Cytokinins; D007210:Indoleacetic Acids; D007211:Indoles; D010937:Plant Growth Regulators; D011687:Purines; D014157:Transcription Factors; C014612:indolebutyric acid; C480551:benzylaminopurine
keywords: Chrysanthemum morifolium; Hormone; Petal growth; RNA-seq; Transcription factor