Molecular Evolution of Maize Ascorbate Peroxidase Genes and Their Functional Divergence

Abstract

Ascorbate peroxidase (APX) is an important antioxidant enzyme. APXs in maize are encoded by multiple genes and exist as isoenzymes. The evolutionary history and functional divergence of the maize APX gene family were analyzed through comparative genomic and experimental data on the Internet in this paper. APX genes in higher plants were divided into classes A, B, and C. Each type of APX gene in angiosperms only had one ancestral gene that was duplicated along with the genome duplication or local (or tandem) duplication of the angiosperm. A total of eight genes were retained in maize and named APXa1, APXa2, APXa3, APXb1, APXb2, APXc1.1, APXc1.2, and APXc2. The APX genes of class A were located in the chloroplasts or mitochondria, and the class B and C genes were localized in the peroxisomes and cytoplasm, respectively. The expression patterns of eight APXs were different in vegetative and reproductive organs at different growth and development stages. APXa1 and APXb1 of maize may participate in the antioxidant metabolism of vegetative organs under normal conditions. APXa2, APXb2, APXc1.1, and APXc1.2 may be involved in the stress response, and APXb2 and APXc2 may participate in the senescence response. These results provide a basis for cultivating high-yield and resistant maize varieties.

Whole-Genome Identification of APX and CAT Gene Families in Cultivated and Wild Soybeans and Their Regulatory Function in Plant Development and Stress Response

“…For 11 APX genes of G. max, 20 orthologue pairs were identified in G. soja , whereas for the CAT gene family, 16 orthologue gene pairs were identified. Similar findings were reported in other crops [ 68 ]. These findings suggest a close relationship between these two species, and a higher level of sequence similarity depicts that although cultivated soybean differs considerably from wild-type soybean, at the genome level, they are quite similar, with sequences found to be conserved from wild to cultivated species.…”

The Modus Operandi of Hydrogen Sulfide(H2S)-Dependent Protein Persulfidation in Higher Plants

“…In higher plants, ascorbate peroxidase (APX) constitutes a good example of a protein whose Cys residues are affected by oxiPTMs. This key antioxidant enzyme, which is present in virtually all subcellular compartments, is a component in the ascorbate-glutathione cycle [ 66 , 67 , 68 , 69 , 70 ]. APX catalyzes the decomposition of H 2 O 2 associated with the oxidation of ascorbate to dehydroascorbate.…”