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Ascorbate peroxidase‐related (APx‐R) is a new heme‐containing protein functionally associated with ascorbate peroxidase but evolutionarily divergent
Author(s) -
Lazzarotto Fernanda,
Teixeira Felipe Karam,
Rosa Silvia Barcelos,
Dunand Christophe,
Fernandes Claudia Lemelle,
de Vasconcelos Fontenele Adilton,
Silveira Joaquim Albenisio Gomes,
Verli Hugo,
Margis Rogério,
MargisPinheiro Marcia
Publication year - 2011
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2011.03659.x
Subject(s) - apx , peroxidase , biology , heme , biochemistry , gene , genetics , enzyme
Summary• Peroxidases are involved in several important processes, such as development and responses to environmental cues. In higher plants, most peroxidases are encoded by large, multigenic families that mainly originated from gene and chromosomal duplications. • Using phylogenetic, genomic and functional analyses, we have identified and characterized a new class of putative heme peroxidases, called ascorbate peroxidase‐related (APx‐R), which arose specifically in the lineage of plants. • The APx‐R protein is structurally related to the ascorbate peroxidases, although the active site contains many conserved substitutions. Unlike all other plant peroxidases, which are encoded by gene families, APx‐R is encoded by a single‐copy gene in virtually all the species analyzed. APx‐R proteins are targeted to the chloroplast and can physically interact with chloroplastic APx proteins. APx‐R‐knockdown rice ( Oryza sativa ) plants presented delayed development and a disturbed steady state of the antioxidant system compared with wild type. Moreover, the accumulation of APx‐R transcripts was modulated by drought, UV irradiation, cold, and aluminum exposure in rice, suggesting the involvement of APx‐R in the environmental stress response. • Our results reveal the existence of a new class of heme peroxidase which seems to play a role in the antioxidant system in plants, probably by modulating the activity of chloroplastic APx proteins.