title: Proline does not quench singlet oxygen: evidence to reconsider its protective role in plants.
abstract: Plants are commonly subjected to several environmental stresses that lead to an overproduction of reactive oxygen species (ROS). As plants accumulate proline in response to stress conditions, some authors have proposed that proline could act as a non-enzymatic antioxidant against ROS. One type of ROS aimed to be quenched by proline is singlet oxygen ((1)O(2))-molecular oxygen in its lowest energy electronically excited state-constitutively generated in oxygenic, photosynthetic organisms. In this study we clearly prove that proline cannot quench (1)O(2) in aqueous buffer, giving rise to a rethinking about the antioxidant role of proline against (1)O(2).
authors: Laboratorio de Bioquímica, Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Av. E. Garzón 780, CP 12900 Montevideo, Uruguay. ssignorelli@fagro.edu.uy
authors: Santiago
authors: S
authors: Signorelli
authors: Juan Bautista
authors: JB
authors: Arellano
authors: Thor Bernt
authors: TB
authors: Melø
authors: Omar
authors: O
authors: Borsani
authors: Jorge
authors: J
authors: Monza
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D018384:Oxidative Stress; D010944:Plants / Q000378:metabolism*; D011392:Proline / Q000378:metabolism*; D026082:Singlet Oxygen / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D026082:Singlet Oxygen; D011392:Proline