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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.

Growing evidence indicates that elongation factor 1&alpha, (EF1&alpha, ) is involved in responses to various abiotic stresses in several plant species. Soybean EF1&alpha, proteins include three structural domains: one GTP-binding domain and two oligonucleotide binding domains that are also called as domain 2 and domain 3. In this study, 10 EF1&alpha, genes were identified in the soybean genome. We predicted structures of different domains and analyzed gene locations, gene structures, phylogenetic relationships, various cis-elements, and conserved domains of soybean EF1&alpha, s. The expression patterns of 10 EF1&alpha, genes were analyzed by quantitative real-time PCR (qRT-PCR). Under drought stress, soybean EF1&alpha, genes were upregulated in varying degrees. In particular, GmEF4 was upregulated under drought and salt treatments. Compared to the drought- and salt-treated empty vector (EV)-control plants, drought- and salt-treated GmEF4-overexpressing (OE) plants had significantly delayed leaf wilting, longer root, higher biomass, higher proline (Pro) content, and lower H2O2, O2&minus, and malondialdehyde (MDA) contents. Thus, this study provides a foundation for further functional genomics research about this important family under abiotic stress.