Overexpression of the Rieske FeS protein of the Cytochrome b6f complex increases C4 photosynthesis in Setaria viridis

Commun Biol. 2019 Aug 16:2:314. doi: 10.1038/s42003-019-0561-9. eCollection 2019.

Abstract

C4 photosynthesis is characterised by a CO2 concentrating mechanism that operates between mesophyll and bundle sheath cells increasing CO2 partial pressure at the site of Rubisco and photosynthetic efficiency. Electron transport chains in both cell types supply ATP and NADPH for C4 photosynthesis. Cytochrome b6f is a key control point of electron transport in C3 plants. To study whether C4 photosynthesis is limited by electron transport we constitutively overexpressed the Rieske FeS subunit in Setaria viridis. This resulted in a higher Cytochrome b6f content in mesophyll and bundle sheath cells without marked changes in the abundances of other photosynthetic proteins. Rieske overexpression plants showed better light conversion efficiency in both Photosystems and could generate higher proton-motive force across the thylakoid membrane underpinning an increase in CO2 assimilation rate at ambient and saturating CO2 and high light. Our results demonstrate that removing electron transport limitations can increase C4 photosynthesis.

Keywords: C4 photosynthesis; Molecular engineering in plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon Dioxide / metabolism
  • Cytochrome b6f Complex / genetics
  • Cytochrome b6f Complex / metabolism*
  • Electron Transport Complex III / genetics
  • Electron Transport Complex III / metabolism*
  • Fluorescence
  • Gene Expression Regulation, Plant / radiation effects
  • Photosynthesis* / radiation effects
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • Proton-Motive Force / radiation effects
  • Setaria Plant / genetics
  • Setaria Plant / physiology*
  • Setaria Plant / radiation effects

Substances

  • Plant Proteins
  • Rieske iron-sulfur protein
  • Carbon Dioxide
  • Cytochrome b6f Complex
  • Electron Transport Complex III