Morphological Characteristics, Anatomical Structure, and Gene Expression: Novel Insights into Cytokinin Accumulation during Carrot Growth and Development

PLoS One. 2015 Jul 28;10(7):e0134166. doi: 10.1371/journal.pone.0134166. eCollection 2015.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytokinins / metabolism*
  • Daucus carota / genetics*
  • Daucus carota / growth & development*
  • Gene Expression Profiling*
  • Gene Expression Regulation, Plant / drug effects
  • Genes, Plant*
  • Plant Growth Regulators / metabolism
  • Plant Roots / genetics*
  • Plant Roots / growth & development*
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction

Substances

  • Cytokinins
  • Plant Growth Regulators
  • RNA, Messenger

Grants and funding

The research was supported by the New Century Excellent Talents in University (NCET-11-0670); Jiangsu Natural Science Foundation (BK20130027); Priority Academic Program Development of Jiangsu Higher Education Institutions; and Shanxi Province Coal Based Key Scientific and Technological Project (FT201402-07). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.