Impairment of Lhca4, a subunit of LHCI, causes high accumulation of chlorophyll and the stay-green phenotype in rice

J Exp Bot. 2018 Feb 23;69(5):1027-1035. doi: 10.1093/jxb/erx468.


Chlorophyll is an essential molecule for acquiring light energy during photosynthesis. Mutations that result in chlorophyll retention during leaf senescence are called 'stay-green' mutants. One of the several types of stay-green mutants, Type E, accumulates high levels of chlorophyll in the pre-senescent leaves, resulting in delayed yellowing. We isolated delayed yellowing1-1 (dye1-1), a rice mutant whose yellowing is delayed in the field. dye1-1 accumulated more chlorophyll than the wild-type in the pre-senescent and senescent leaves, but did not retain leaf functionality in the 'senescent green leaves', suggesting that dye1-1 is a Type E stay-green mutant. Positional cloning revealed that DYE1 encodes Lhca4, a subunit of the light-harvesting complex I (LHCI). In dye1-1, amino acid substitution occurs at the location of a highly conserved amino acid residue involved in pigment binding; indeed, a severely impaired structure of the PSI-LHCI super-complex in dye1-1 was observed in a blue native PAGE analysis. Nevertheless, the biomass and carbon assimilation rate of dye1-1 were comparable to those in the wild-type. Interestingly, Lhcb1, a trimeric LHCII protein, was highly accumulated in dye1-1, in the chlorophyll-protein complexes. The high accumulation of LHCII in the LHCI mutant dye1 suggests a novel functional interaction between LHCI and LHCII.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Light-Harvesting Protein Complexes
  • Oryza / genetics*
  • Oryza / metabolism*
  • Phenotype
  • Photosynthesis*
  • Pigmentation / genetics
  • Plant Leaves / physiology*


  • Light-Harvesting Protein Complexes