Cloning and functional analysis of a novel ascorbate peroxidase (APX) gene from Anthurium andraeanum

Abstract

An 888-bp full-length ascorbate peroxidase (APX) complementary DNA (cDNA) gene was cloned from Anthurium andraeanum, and designated as AnAPX. It contains a 110-bp 5′-noncoding region, a 28-bp 3′-noncoding region, and a 750-bp open reading frame (ORF). This protein is hydrophilic with an aliphatic index of 81.64 and its structure consisting of α-helixes, β-turns, and random coils. The AnAPX protein showed 93%, 87%, 87%, 87%, and 86% similarities to the APX homologs from Zantedeschia aethiopica, Vitis pseudoreticulata, Gossypium hirsutum, Elaeis guineensis, and Zea mays, respectively. AnAPX gene transcript was measured non-significantly in roots, stems, leaves, spathes, and spadices by real-time polymerase chain reaction (RT-PCR) analysis. Interestingly, this gene expression was remarkably up-regulated in response to a cold stress under 6 °C, implying that AnAPX might play an important role in A. andraeanum tolerance to cold stress. To confirm this function we overexpressed AnAPX in tobacco plants by transformation with an AnAPX expression construct driven by CaMV 35S promoter. The transformed tobacco seedlings under 4 °C showed less electrolyte leakage (EL) and malondialdehyde (MDA) content than the control. The content of MDA was correlated with chilling tolerance in these transgenic plants. These results show that AnAPX can prevent the chilling challenged plant from cell membrane damage and ultimately enhance the plant cold tolerance.

Gamma irradiation enhancement of biofilm production in Bacillus amyloliquifaciens and effect of mutants’ inoculation on APX1 expression in salt-stressed Egyptian barley

“…MSA showed that highly conserved regions appeared on the N-terminal, while weakly conserved sequences existed on the C-terminal, as well as several conserved residues that constitute a potential active site for metal binding, were observed. These findings agree with the study of Liu et al (2013). In addition, the presence of a significant degree of conserved residues in the main sites of the enzyme has been demonstrated (Ozyigit et al, 2016).…”

“…Accumulation of ROS will generate an oxidative stress condition, which leads to suppression of plant growth. However, plants have established their protection systems (nonenzymatic and enzymatic ROS scavenging systems) against such oxidative stress (Sharma et al, 2012;Liu et al, 2013). A nonenzymatic system employs antioxidants to diminish ROS such as glutathione (GSH), AsA, and flavonoids, while an enzymatic system utilizes many enzymes, including ascorbate peroxidase (APX), superoxide dismutase (SOD), glutathione reductase (GSH), and catalase (CAT).…”

“…Ascorbate peroxidase (APX), glutathione peroxidase (GPX), and catalase (CAT) are the primary enzymes in charge of repressing the toxic levels of H 2 O 2 (Apel and Hirt, 2004). Interestingly, APX also plays essential roles in ROS-scavenging, since even very low concentrations are adequate for breaking down H 2 O 2 (Liu et al, 2013;Anjum et al, 2014;Sofo et al, 2015). APX (EC 1.11.1.11) is a member of the plant-type heme peroxidase superfamily (Lazzarotto et al, 2011).…”

Overexpression ofCaAPXInduces Orchestrated Reactive Oxygen Scavenging and Enhances Cold and Heat Tolerances in Tobacco

“…Raj3765 displayed up to 203-fold level of expression at 42°C heat stress exposure. The expression level of tAPX during cold acclimation of wheat was upregulated [47]; the expression of A. andraeanum APX mRNA was evidently elevated by cold stress [48]; OsAPX2 expression of Oryza sativa was also developmental- and spatial-regulated and was induced by cold stress [49]. In this study, the expression levels of CaAPX were both remarkably upregulated under low and high temperature treatment (Figures 1(d) and 1(e)).…”

A Novel L-ascorbate Peroxidase 6 Gene, ScAPX6, Plays an Important Role in the Regulation of Response to Biotic and Abiotic Stresses in Sugarcane

“…Subcellular localization of ScAPX6 in rice protoplast showed that ScAPX6::GFP was targeted at chloroplast (Figure 4 ), which was consistent with the result of bioinformatics predicted localization. Similar to other plant species, such as the APXs from Cucumis melo (Cheng et al, 2009 ) and A. andraeanum (Liu et al, 2013 ), ScAPX6 also contained a plant peroxidase like superfamily and the heme binding site and shared 94.29 and 82.93% similarities with the APX homologs from S. italic APX6 (XP_004973913.1) and S. bicolor APX6 (XP_002445876.1), suggesting that ScAPX6 belongs to a member of APX family.…”