Delayed degradation of chlorophylls and photosynthetic proteins in Arabidopsis autophagy mutants during stress-induced leaf yellowing

Yasuhito Sakuraba, Sang Hwa Lee, Ye Sol Kim, Ohkmae Kim, Stefan Hörtensteiner, Nam Chon Paek

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Plant autophagy, one of the essential proteolysis systems, balances proteome and nutrient levels in cells of the whole plant. Autophagy has been studied by analysing Arabidopsis thaliana autophagy-defective atg mutants, but the relationship between autophagy and chlorophyll (Chl) breakdown during stress-induced leaf yellowing remains unclear. During natural senescence or under abiotic-stress conditions, extensive cell death and early yellowing occurs in the leaves of atg mutants. A new finding is revealed that atg5 and atg7 mutants exhibit a functional stay-green phenotype under mild abiotic-stress conditions, but leaf yellowing proceeds normally in wild-type leaves under these conditions. Under mild salt stress, atg5 leaves retained high levels of Chls and all photosystem proteins and maintained a normal chloroplast structure. Furthermore, a double mutant of atg5 and non-functional stay-green nonyellowing1-1 (atg5 nye1-1) showed a much stronger stay-green phenotype than either single mutant. Taking these results together, it is proposed that autophagy functions in the non-selective catabolism of Chls and photosynthetic proteins during stress-induced leaf yellowing, in addition to the selective degradation of Chl-apoprotein complexes in the chloroplasts through the senescence-induced STAY-GREEN1/NYE1 and Chl catabolic enzymes.

Original languageEnglish
Pages (from-to)3915-3925
Number of pages11
JournalJournal of Experimental Botany
Volume65
Issue number14
DOIs
Publication statusPublished - 2014 Jul 1
Externally publishedYes

Keywords

  • Abiotic stress
  • Arabidopsis thaliana
  • atg5
  • autophagy
  • chlorophyll degradation
  • leaf senescence
  • stay-green.

ASJC Scopus subject areas

  • Medicine(all)

Fingerprint Dive into the research topics of 'Delayed degradation of chlorophylls and photosynthetic proteins in Arabidopsis autophagy mutants during stress-induced leaf yellowing'. Together they form a unique fingerprint.

  • Cite this