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 the yield of crops. Peroxidases (PRXs) are involved in various abiotic stress responses. Furthermore, only few wheat PRXs have been characterized in the mechanism of the abiotic stress response. Results: In this study, a novel wheat peroxidase (PRX) gene named TaPRX-2A, a member of wheat class III PRX gene family, was cloned and its response to salt stress was characterized. Based on the identification and evolutionary analysis of class III PRXs in 12 plants, we proposed an evolutionary model for TaPRX-2A, suggesting that occurrence of 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. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) results showed that TaPRX-2A exhibited relatively higher expression levels in root tissue than those exhibited in leaf and stem tissues. TaPRX-2A expression was also induced by abiotic stresses and hormone treatments such as polyethylene glycol 6000, 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 cell nuclei. Survival rate, relative water content, and shoot length were higher in TaPRX-2A-overexpressing wheat than in the WT wheat, whereas root length was not significantly different. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were enhanced in TaPRX-2Aoverexpressing wheat compared with those in the WT wheat, resulting in the reduction of reactive oxygen species (ROS) accumulation and malondialdehyde (MDA) content. The expression levels of downstream stress-related genes showed that RD22, TLP4, ABAI, GST22, FeSOD, and CAT exhibited higher expressions in TaPRX-2A-overexpressing wheat than in WT under salt stress. Conclusions: The results show that TaPRX-2A plays a positive role in the response to salt stress by scavenging ROS and regulating stress-related genes.

Genome-Wide Identification and Analysis of the Class III Peroxidase Gene Family in Tobacco (Nicotiana tabacum)

“…Some genetic evidences suggested that class III peroxidase is an abiotic stress-responsive enzyme in different plant species. For example, the overexpression of AtPrx64 could enhance the tolerance of tobacco to aluminum stress ( Wu et al, 2017 ), and the overexpression of TaPRX-2A in wheat exhibited an enhanced tolerance to salt stress ( Su et al, 2020 ). Similarly, the overexpression of CrPRX, a Catharanthus roseus peroxidase, improved tolerance of tobacco to salt and drought stress ( Jaggi et al, 2011 ).…”

Comparative Transcriptomics Reveals Osmotic and Ionic Stress Key Genes Contributing To Salinity Tolerance Differential in Two Pak Choi Cultivars

“…Antioxidant defence system can alleviate oxidative damage in response to salinity/oxidative stress [1,4,21]. Our physiological work showed that the antioxidative enzymes, POD (Fig.…”

“…In addition, salinity stress tolerance mechanisms also include a series of ROS scavenging enzyme genes [4], compatible solute synthesis genes [4,19,20] and ion transporters [1,4], which enhance plant adaptations to salinity stress. Some studies have shown that overexpression of the stress-associated genes encoding the ROS scavenging protein TaPRX-2A [21], compatible solute KvP5CS1 [22], ion transporter AtNHX1 [23] and SpSOS1/NHX7 [10] results in enhanced tolerance to salinity stress in transgenic plants, respectively.…”

Evolutionary Implications of a Peroxidase with High Affinity for Cinnamyl Alcohols from Physcomitrium patens, a Non-Vascular Plant

“…This bryophyte is thus a useful tool to study responses to abiotic stress. Peroxidases are enzymes known to change their expression pattern in response to different types of stress [ 16 , 17 ]. Here, we selected different abiotic stresses and monitored in a time course both peroxidase activity and isoform pattern from protein extracts of P. patens gametophores grown in liquid medium.…”