The Maize WRKY Transcription Factor ZmWRKY40 Confers Drought Resistance in Transgenic Arabidopsis

Abstract

Abiotic stresses restrict the growth and yield of crops. Plants have developed a number of regulatory mechanisms to respond to these stresses. WRKY transcription factors (TFs) are plant-specific transcription factors that play essential roles in multiple plant processes, including abiotic stress response. At present, little information regarding drought-related WRKY genes in maize is available. In this study, we identified a WRKY transcription factor gene from maize, named ZmWRKY40. ZmWRKY40 is a member of WRKY group II, localized in the nucleus of mesophyll protoplasts. Several stress-related transcriptional regulatory elements existed in the promoter region of ZmWRKY40. ZmWRKY40 was induced by drought, high salinity, high temperature, and abscisic acid (ABA). ZmWRKY40 could rapidly respond to drought with peak levels (more than 10-fold) at 1 h after treatment. Overexpression of ZmWRKY40 improved drought tolerance in transgenic Arabidopsis by regulating stress-related genes, and the reactive oxygen species (ROS) content in transgenic lines was reduced by enhancing the activities of peroxide dismutase (POD) and catalase (CAT) under drought stress. According to the results, the present study may provide a candidate gene involved in the drought stress response and a theoretical basis to understand the mechanisms of ZmWRKY40 in response to abiotic stresses in maize.

A Wheat WRKY Transcription Factor TaWRKY46 Enhances Tolerance to Osmotic Stress in transgenic Arabidopsis Plants

“…WRKY TFs are one of the largest families of transcriptional regulators in plants, and have multiple developmental and physiological functions in response to environmental stresses [30]. In plants such as rice [31], soybean [16,32], cotton [33], Brachypodium distachyon [34,35], maize [36], and wheat [37], an especially large number of WRKY proteins have been identified in recent years.…”

Cytosolic TaGAPC2 Enhances Tolerance to Drought Stress in Transgenic Arabidopsis Plants

“…WRKY transcription factors are one of the largest families of transcriptional regulators in plants, and are involved in the drought-related response [ 27 ]. In plants such as wheat [ 28 ], rice [ 29 ], brachypodium distachyon [ 30 ], maize [ 31 ], soybean [ 32 ], and cotton [ 33 ], a large number of WRKYs have been identified in recent years. In our previous study, we identified that TaWRKY28, TaWRKY33, TaWRKY40, and TaWRKY47 preferentially bind to specific W-box in cw-TaGApC5 ( cw-TaGApC2-6D ) and zy-TaGApC5 ( zy-TaGApC2-6D ) by Y1H and EMSA (Electrophoretic Mobility Shift Assay) analyses [ 25 ].…”

Transcription Factors in Plant Stress Responses: Challenges and Potential for Sugarcane Improvement

“…Ancient gene transfer events were considered as the origin of these non-plant WRKYs based on distribution pattern analysis [11]. Numerous WRKY TFs have been experimentally revealed in various plant species, including (Arabidopsis thaliana) [12], sugarcane (Saccharum spontaneum) [13], barley (Hordeum vulgare) [14], rice (Oryza sativa) [15], physic nut (Jatropha curcas) [16], maize (Zea mays) [17], wheat (Triticum aestivum) [18], cotton (Gossypium hirsutum) [19] and so on (Table 1).…”

“…In sugarcane, a WRKY-IIc TF gene ScWRKY3 played positive regulation by sodium chloride (NaCl), polyethylene glycol (PEG), and abscisic acid (ABA), but it was suppressed by salicylic acid (SA) and methyl jasmonate (MeJA) [38]. In other crops, overexpression of TaWRKY93 [39], ZmWRKY40 [17], TaWRKY2 [40], GhWRKY91 [41] and GmWRKY54 [42] conferred drought tolerance through ABA, Ca 2+ -mediated signal transduction pathways and osmotic adjustments.…”