Gibberellin regulates pollen viability and pollen tube growth in rice

Plant Cell. 2007 Dec;19(12):3876-88. doi: 10.1105/tpc.107.054759. Epub 2007 Dec 14.

Abstract

Gibberellins (GAs) play many biological roles in higher plants. We collected and performed genetic analysis on rice (Oryza sativa) GA-related mutants, including GA-deficient and GA-insensitive mutants. Genetic analysis of the mutants revealed that rice GA-deficient mutations are not transmitted as Mendelian traits to the next generation following self-pollination of F1 heterozygous plants, although GA-insensitive mutations are transmitted normally. To understand these differences in transmission, we examined the effect of GA on microsporogenesis and pollen tube elongation in rice using new GA-deficient and GA-insensitive mutants that produce semifertile flowers. Phenotypic analysis revealed that the GA-deficient mutant reduced pollen elongation1 is defective in pollen tube elongation, resulting in a low fertilization frequency, whereas the GA-insensitive semidominant mutant Slr1-d3 is mainly defective in viable pollen production. Quantitative RT-PCR revealed that GA biosynthesis genes tested whose mutations are transmitted to the next generation at a lower frequency are preferentially expressed after meiosis during pollen development, but expression is absent or very low before the meiosis stage, whereas GA signal-related genes are actively expressed before meiosis. Based on these observations, we predict that the transmission of GA-signaling genes occurs in a sporophytic manner, since the protein products and/or mRNA transcripts of these genes may be introduced into pollen-carrying mutant alleles, whereas GA synthesis genes are transmitted in a gametophytic manner, since these genes are preferentially expressed after meiosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Flowers / drug effects
  • Flowers / genetics
  • Flowers / growth & development
  • Gene Expression Regulation, Plant / drug effects
  • Genes, Plant / genetics
  • Genetic Complementation Test
  • Gibberellins / metabolism
  • Gibberellins / pharmacology*
  • Gibberellins / physiology
  • Molecular Sequence Data
  • Mutation
  • Oryza / drug effects*
  • Oryza / genetics
  • Oryza / growth & development
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plant Proteins / physiology
  • Plants, Genetically Modified
  • Pollen / drug effects*
  • Pollen / genetics
  • Pollen / growth & development
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / drug effects
  • Signal Transduction / genetics

Substances

  • Gibberellins
  • Plant Proteins

Associated data

  • GENBANK/AAC49067
  • GENBANK/AB100246
  • GENBANK/AK066285
  • GENBANK/AK069429
  • GENBANK/AK074026
  • GENBANK/AK100333
  • GENBANK/AK102841
  • GENBANK/AY347878
  • GENBANK/BAE96289