Required to trigger chlorophyll degradation during leaf senescence and fruit ripening (PubMed:18359841, Ref.3, PubMed:23406468). Binds directly PSY1 to regulate the accumulation of lycopene and beta-carotene in the maturing fruits (PubMed:23406468). Interacts with PSY1. Expressed during fruit ripening, but not during fruit development (PubMed:18359841, Ref.3). Expressed during leaf senescence, but not during leaf development (Ref.3). Induced by drougt stress in leaves and stems. Plants silencing SGR1 exhibit a stay-green leaf phenotype during leaf senescence, and a red-brown fruit phenotype in mature fruit (Ref.3, PubMed:23406468). Plants silencing SGR1 exhibit altered development of fruit pericarp cells (PubMed:23406468). Belongs to the staygreen family.