PRX9 and PRX40 Are Extensin Peroxidases Essential for Maintaining Tapetum and Microspore Cell Wall Integrity during Arabidopsis Anther Development

Plant Cell. 2019 Apr;31(4):848-861. doi: 10.1105/tpc.18.00907. Epub 2019 Mar 18.

Abstract

Pollen and microspore development are essential steps in the life cycle of all land plants that generate male gametes. Within flowering plants, pollen development occurs inside of the anther. Here, we report the identification of two class III peroxidase-encoding genes, PEROXIDASE9 (PRX9) and PRX40, that are genetically redundant and essential for proper anther and pollen development in Arabidopsis (Arabidopsis thaliana). Arabidopsis double mutants devoid of functional PRX9 and PRX40 are male sterile. The mutant anthers display swollen, hypertrophic tapetal cells and pollen grains, suggesting disrupted cell wall integrity. These phenotypes lead to nearly 100%-penetrant pollen degeneration upon anther maturation. Using immunochemical and biochemical approaches, we show that PRX9 and PRX40 likely cross-link extensins to contribute to tapetal cell wall integrity during anther development. This work suggests that PRX9 and PRX40 encode Arabidopsis extensin peroxidases and highlights the importance of extensin cross-linking during pollen development.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cell Wall / genetics
  • Cell Wall / metabolism
  • Cell Wall / physiology
  • Gene Expression Regulation, Plant / genetics
  • Gene Expression Regulation, Plant / physiology
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism*
  • Plants, Genetically Modified / physiology

Substances

  • Arabidopsis Proteins