The overexpression of a maize mitogen-activated protein kinase gene (ZmMPK5) confers salt stress tolerance and induces defence responses in tobacco

• Published in: Plant biology (Stuttgart, Germany) Germany), 2014-05, Vol.16 (3), p.558-570
• Main Authors: Zhang, D., Jiang, S., Pan, J., Kong, X., Zhou, Y., Liu, Y., Li, D.
• Format: Article
• Language: English
• Subjects: Antioxidants - metabolism; Cloning, Molecular; Disease Resistance - drug effects; Disease Resistance - immunology; Electric Conductivity; Gene Expression Profiling; Gene Expression Regulation, Plant - drug effects; Germination - drug effects; Germination - genetics; Mitogen-Activated Protein Kinases - genetics; Mitogen-Activated Protein Kinases - metabolism; Nicotiana - drug effects; Nicotiana - genetics; Nicotiana - immunology; Nicotiana - virology; Oxidative stress; Oxidative Stress - drug effects; Oxidative Stress - genetics; pathogen defence; Phylogeny; Plant Diseases - immunology; Plant Diseases - virology; Plant Growth Regulators - metabolism; Plant Proteins; Plants, Genetically Modified; Potexvirus - drug effects; Potexvirus - physiology; Reactive Oxygen Species - metabolism; ROS; salt stress; Salt Tolerance - drug effects; Salt Tolerance - genetics; Seedlings - drug effects; Seedlings - growth & development; Seedlings - physiology; Signal Transduction - drug effects; Signal Transduction - genetics; Sodium Chloride - pharmacology; Stress, Physiological - drug effects; Stress, Physiological - genetics; Zea mays; Zea mays - drug effects; Zea mays - enzymology; Zea mays - genetics; Zea mays - physiology; ZmMPK5
• ISSN: 1435-8603; 1438-8677
• DOI: 10.1111/plb.12084

As sessile organisms, plants are exposed to potential dangers, including multiple biotic and abiotic stresses. The mitogen-activated protein kinase (MAPK) is a universal signalling pathways involved in these processes. A previous study showed that maize ZmMPK5 is induced by various stimuli at transcriptional and post-translational levels. In this study, ZmMPK5 was overexpressed in tobacco to further analyse its biological functions. Under salt and oxidative stresses, ZmMPK5-overexpressing lines displayed less severe damage and stronger growth phenotypes corresponding to a series of physiological changes. In addition, the transgenic lines accumulated less reactive oxygen species (ROS) and had higher levels of antioxidant enzyme activity and metabolites than wild-type (WT) plants following NaCl treatment. Quantitative RT-PCR revealed that the expression of ROS-related and stress-responsive genes was higher in transgenic plants than in WT plants. Furthermore, transgenic lines exhibited enhanced resistance to viral pathogens, and expressed constitutively higher transcript levels of pathogenesis-related genes, such as PR1a, PR4, PR5 and EREBP. Taken together, these results demonstrated that ZmMPK5 is involved in salt stress, oxidative stress and pathogen defence signalling pathways, and its function may be at least partly devoted to efficiently eliminating ROS accumulation under salt stress.