A member of wheat class III peroxidase gene family, TaPRX-2A, enhanced the tolerance of salt stress

Abstract

Background: Salt and drought are the main abiotic stresses that restrict yield of crops. It is reported that peroxidases (PRXs) are involved in various abiotic stress responses. However, few wheat PRXs are characterized in the mechanism of abiotic stresses. Results: In this study, a novel wheat peroxidase (PRX) gene named TaPRX-2A, a member of wheat class III peroxidase gene family, was cloned and characterized in salt stress response. Based on the identification and evolutionary analysis of class III PRXs in 12 plants, we proposed an evolutionary model that TaPRX-2A might have experienced some exon fusion events during evolution. We also detected the positive selection of PRX domain in 13 PRXs involving our evolutionary model, and found 2 or 6 positively selected sites during TaPRX-2A evolution. The results of expression pattern showed that TaPRX-2A exhibited relatively higher expression levels in root tissue compared with that of leaf and stem tissues by using qRT-PCR. This TaPRX-2A was also induced by some stresses and hormone treatments including PEG6000, NaCl, hydrogen peroxide (H 2 O 2 ), salicylic acid (SA), methyljasmonic acid (MeJA) and abscisic acid (ABA). Transgenic wheat plants with overexpression of TaPRX-2A showed higher tolerance to salt stress than wild type (WT) plants. Confocal microscopy revealed that TaPRX-2A :eGFP was mainly localized in nuclei. The survival rate, relative water content and shoot length were higher in TaPRX-2A -overexpressing wheat than WT. However, root lengths were no significant difference between transgenic wheat and WT. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were enhanced in TaPRX-2A -overexpressing wheat than WT, resulting in the reduction of reactive oxygen species (ROS) accumulation and malondialdehyde (MDA) content. We also measured the expression levels of downstream stress-related genes ( RD22 , TLP4 , ABAI , GLP4 , GST22 , FeSOD, CuSOD, and CAT ). The results showed that RD22 , TLP4 , ABAI , GST22 , FeSOD, and CAT exhibited higher expression in TaPRX-2A -overexpressing lines than in WT under salt stress. Conclusions: The results show that TaPRX-2A plays a positive factor in response to salt stress by scavenging ROS and regulating stress-related genes.

The IbBBX24–IbTOE3–IbPRX17 module enhances abiotic stress tolerance by scavenging reactive oxygen species in sweet potato

“…Overexpression of the wild soybean (Glycine soja) GsPRX9 gene was associated with improved salt tolerance in soybean (Glycine max) (Jin et al, 2019). Overexpressing TaPRX-2A in wheat (Triticum aestivum) also increased the tolerance of transgenic lines to salt stress (Su et al, 2020). However, the biological functions and regulatory mechanisms of most CIII PRXs remain unclear.…”

“…Class III PRX genes encode heme-containing enzymes that accept electrons from various donors to catalyze H 2 O 2 metabolism, thus reducing H 2 O 2 concentrations inside plant tissues (Almagro et al, 2009). Class III PRXs are important in protecting against ROS and enhance stress tolerance in plants exposed to salt (Llorente et al, 2002;Kumar et al, 2012;Jin et al, 2019;Su et al, 2020), drought (Llorente et al, 2002;Kumar et al, 2012), cold (Kim et al, 2012) and heat (Requesens et al, 2014) stresses. However, the biological functions and regulatory mechanisms of most CIII PRX genes remain unclear.…”

Regulation of Drought and Salt Tolerance by OsSKL2 and OsASR1 in Rice

“…Accordingly, tolerant species possess a number of ROS detoxifying proteins, such as CAT, POD and SOD, which protect them from oxidative stress (Azevedo-Neto et al 2006). For example, overexpression of IbBBX24 and IbBBX17 in sweet potato improved tolerance to drought and salt stress via scavenging and detoxi cation of ROS (Zhang et al 2022), while transgenic Triticum aestivum overexpressing TaPRX-2A showed increased tolerance to salt as a result of reduced ROS accumulation (Su et al 2020). In this study, overexpression of OsSKL2 in rice reduced H 2 O 2 accumulation and improved the activities of CAT, POD and SOD, thereby enhancing tolerance to drought and salt stress (Fig.…”

Comparative transcriptome analysis of root types in salt tolerant and sensitive rice varieties in response to salinity stress

“…In terms of antioxidant activity, several genes that code for peroxidases were detected in both Mulai and IR29. The role of peroxidase genes in salinity tolerance in soybean (Jin et al 2019) and wheat (Su et al 2020) has been demonstrated, while the regulation of peroxidase biosynthesis by a zinc finger protein has been shown in rice salinity tolerance (Cui et al 2015). The generation of reactive oxygen species (ROS) as brought about by abiotic stresses such as salinity and its negative effects has been well documented in different crops.…”