title: Morphological Characteristics, Anatomical Structure, and Gene Expression: Novel Insights into Cytokinin Accumulation during Carrot Growth and Development.
abstract: Cytokinins have been implicated in normal plant growth and development. These bioactive molecules are essential for cell production and expansion in higher plants. Carrot is an Apiaceae vegetable with great value and undergoes significant size changes over the process of plant growth. However, cytokinin accumulation and its potential roles in carrot growth have not been elucidated. To address this problem, carrot plants at five stages were collected, and morphological and anatomical characteristics and expression profiles of cytokinin-related genes were determined. During carrot growth and development, cytokinin levels were the highest at the second stage in the roots, whereas relatively stable levels were observed in the petioles and leaves. DcCYP735A2 showed high expression at stage 2 in the roots, which may contribute largely to the higher cytokinin level at this stage. However, expression of most metabolic genes did not follow a pattern similar to that of cytokinin accumulation, indicating that cytokinin biosynthesis was regulated through a complex network. Genes involved in cytokinin signal perception and transduction were also integrated to normal plant growth and development. The results from the present work suggested that cytokinins may regulate plant growth in a stage-dependent manner. Our work would shed novel insights into cytokinin accumulation and its potential roles during carrot growth. Further studies regarding carrot cytokinins may be achieved by modification of the genes involved in cytokinin biosynthesis, inactivation, and perception.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Guang-Long
authors.initials: GL
authors.lastname: Wang
authors.affiliation: College of Horticulture, Shanxi Agricultural University, Taigu, 030801, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Sun
authors.affiliation: College of Horticulture, Shanxi Agricultural University, Taigu, 030801, China.
authors.forename: Guo-Ming
authors.initials: GM
authors.lastname: Xing
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Xue-Jun
authors.initials: XJ
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Ai-Sheng
authors.initials: AS
authors.lastname: Xiong
mesh_terms: D003583:Cytokinins / Q000378:metabolism*; D018552:Daucus carota / Q000235:genetics* / Q000254:growth & development*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
chemical_list: D003583:Cytokinins; D010937:Plant Growth Regulators; D012333:RNA, Messenger