Characterization of sck1, a novel Castanea mollissima mutant with the extreme short catkins and decreased gibberellin

PLoS One. 2012;7(8):e43181. doi: 10.1371/journal.pone.0043181. Epub 2012 Aug 15.

Abstract

A novel Chinese chestnut (Castanea mollissima Bl.) mutant with extreme short catkins, here was named sck1 and has been characterized in the present study. This sck1 caused 6-fold shorter than wild-type catkins. Endogenous gibberellic acids markedly decreased in the mutant, and application of exogenous GA(3) could partially restore the sck1 phenotype to the wild-type phenotype. Paclobutrazol (PP(333)), an antagonist of GAs biosynthesis, could significantly inhibit the wild-type catkins growth, and lead to a short catkins phenotype similar to the sck1. In addition, compared to the wild-type catkins, the mRNA expression level of ent-kaurenoic acid oxidase (KAO), a gibberellin biosynthesis key gene, was significantly down-regulated (P<0.01) in the sck1. Importantly, transient over-expression of a normal CmKAO gene in short catkins also could partially restore the wild-type phenotype. Real-time PCR and semi-quantitative analysis showed that the mRNA expression level of KAO was significantly up-regulated. In addition, transient RNA interference of CmKAO in wild-type catkins led the mRNA expression level of KAO decrease significantly and inhibited the wild-type catkins elongation strongly. Taken together, our results suggest that the lower gibberellic acids content that is due to decreased CmKAO expression level may contribute to the generation of the extreme short male catkins, sck1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cloning, Molecular
  • Gene Expression Regulation, Plant*
  • Gibberellins / genetics
  • Mixed Function Oxygenases / genetics*
  • Mutation
  • Nuts / genetics*
  • Phenotype
  • Plant Leaves / metabolism
  • Plant Shoots / metabolism
  • Polymerase Chain Reaction / methods
  • Promoter Regions, Genetic
  • RNA / metabolism
  • RNA Interference
  • RNA, Messenger / metabolism

Substances

  • Gibberellins
  • RNA, Messenger
  • RNA
  • gibberellic acid
  • Mixed Function Oxygenases
  • ent-kaurenoic acid oxidase

Grants and funding

This work was provided by the National Natural Science Foundation of China (grant no. 30872039) (http://www.nsfc.gov.cn/Portal0/default152.htm), the Beijing Municipal Natural Science Foundation (grant no. 6092003 and 6082004) (http://www.bjnsf.org/), the Beijing New-Star Program of Science and Technology (grant no. 2007B031) (http://www.bjkw.gov.cn/n8785584/index.html). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.