The Divergent Roles of STAYGREEN (SGR) Homologs in Chlorophyll Degradation

Mol Cells. 2015 May;38(5):390-5. doi: 10.14348/molcells.2015.0039. Epub 2015 Apr 24.

Abstract

Degradation of chlorophyll (Chl) by Chl catabolic enzymes (CCEs) causes the loss of green color that typically occurs during senescence of leaves. In addition to CCEs, staygreen1 (SGR1) functions as a key regulator of Chl degradation. Although sgr1 mutants in many plant species exhibit a stay-green phenotype, the biochemical function of the SGR1 protein remains elusive. Many recent studies have examined the physiological and molecular roles of SGR1 and its homologs (SGR2 and SGR-LIKE) in Chl metabolism, finding that these proteins have different roles in different species. In this review, we summarize the recent studies on SGR and discuss the most likely functions of SGR homologs.

Keywords: SGR-LIKE (SGRL); STAYGREEN (SGR); abiotic stress; chlorophyll catabolic enzymes; chlorophyll degradation.

Publication types

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

MeSH terms

  • Cellular Senescence
  • Chlorophyll / metabolism*
  • Phylogeny
  • Plant Leaves / cytology
  • Plant Leaves / physiology
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism*
  • Plants / genetics
  • Plants / metabolism
  • Sequence Homology

Substances

  • Plant Proteins
  • Chlorophyll