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

Abstract

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.

Genome-Wide Identification and Expression Analysis of the Mitogen-Activated Protein Kinase Gene Family in Cassava

“…In recent years, lots of MAPK genes have been identified to be salt stress responsive, including MPK9, MPK10, MPK11, MPK17 , and MPK18 in Arabidopsis, and OsMAPK4, OsMAPK5 , and OsMAPK44 in rice (Fu et al, 2002; Xiong and Yang, 2003; Jeong et al, 2006; Khaled et al, 2008). Furthermore, overexpressing MAPKs in rice (such as OsMAPK5, OsMAPK44 ), Arabidopsis (such as GhMPK17, ZmSIMK1 ) and tobacco (such as ZmMPK5, GhMPK2 ) could greatly improve salt tolerance of transgenic plants (Xiong and Yang, 2003; Jeong et al, 2006; Gu et al, 2010; Zhang et al, 2011, 2014a,b). Nonetheless, some MAPKs were reported as having negative regulatory roles in salt tolerance, such as the OsMAPK33 gene (Lee et al, 2011).…”

Elucidating the molecular mechanisms mediating plant salt‐stress responses

“…Damage control and repair systems are largely conserved across plant genera; therefore, pretreatment with one type of stress condition can enhance resistance to other stresses. Overexpression of a single gene in detoxification signaling can confer resistance or tolerance to most abiotic stresses in plants (Zhang et al ., ).…”

Investigation of the ASR family in foxtail millet and the role of ASR1 in drought/oxidative stress tolerance

“…Before re-watering, leaves were harvested for measurement of relative water content (RWC), ion leakage, chlorophyll content, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and malonaldehyde (MDA) activities Hu et al 2013;Zhang et al 2014a). All experiments were triplicated.…”