Overexpression of a WRKY transcription factor McWRKY57-like from Mentha canadensis L. enhances drought tolerance in transgenic Arabidopsis

Abstract

Background Drought has become a major environmental problem affecting crop production. Members of the WRKY family play important roles in plant development and stress responses. However, their roles in mint have been barely explored. Results In this study, we isolated a drought-inducible gene McWRKY57-like from mint and investigated its function. The gene encodes a group IIc WRKY transcription factor, McWRKY57-like, which is a nuclear protein with a highly conserved WRKY domain and a C2H2 zinc-finger structure, and has transcription factor activity. Its expression levels were examined in different tissues of mint and under the treatment of mannitol, NaCl, abscisic acid, and methyl jasmonate. We found that McWRKY57-like overexpression in Arabidopsis significantly increased drought tolerance. Further studies showed that under drought stress, McWRKY57-like-overexpressing plants had higher chlorophyll, soluble sugar, soluble protein, and proline contents but lower water loss rate and malondialdehyde content than wild-type plants. Moreover, the activities of antioxidant enzymes catalase, superoxide dismutase, and peroxidase were enhanced in McWRKY57-like transgenic plants. Furthermore, qRT-PCR analysis revealed that the drought-related genes AtRD29A, AtRD29B, AtRD20, AtRAB18, AtCOR15A, AtCOR15B, AtKIN2, and AtDREB1A were upregulated in McWRKY57-like transgenic plants than in wild-type Arabidopsis under simulated drought conditions. Conclusion These data demonstrated that McWRKY57-like conferred drought tolerance in transgenic Arabidopsis by regulating plant growth, osmolyte accumulation and antioxidant enzyme activities, and the expression of stress-related genes. The study indicates that McWRKY57-like plays a positive role in drought response in plants.

Integrative physiological, metabolomic, and transcriptomic analysis reveals the drought responses of two apple rootstock cultivars

“…6 A-B). Numerous studies have shown that four TF families (MYB, AP2/ERF, NAC, and WRKY) play an important role in the response of plants to drought, temperature, salinity, and other types of abiotic stress [ 34 – 39 ]. Analysis of the TFs of these four families revealed that drought stress resulted in consistent changes in the expression of most of the common differentially expressed TFs in the leaves of these two apple rootstock varieties, with the exception of NAC ( MD10G1133400 ), WRKY ( MD07G1234700 and MD01G1168600 ), and AP2/ERF ( MD09G1084100 ), which were significantly up-regulated in ‘Jizhen-2’ but significantly down-regulated in ‘ZC9-3’ (Fig.…”

Transcriptome Analysis Reveals Drought-Responsive Pathways and Key Genes of Two Oat (Avena sativa) Varieties

“…Many studies have shown that the rapid response of WRKY family genes to drought stress and the rapid upregulation of their expression are beneficial for improving drought tolerance in crops [ 13 , 14 ]. The WRKY family genes ZmWRKY106, ZmWRKY40, McWRKY57-like, TaWRKY1-2D, IgWRKY50 and IgWRKY32 increase the activities of superoxide dismutase (SOD), peroxide dismutase and catalase (CAT) and decrease the content of ROS under drought stress, which helps to reduce the accumulation of H 2 O 2 and MDA and improve the drought tolerance of transgenic plants [ 14 , 15 , 40 , 41 ]. In addition, the AtPOD1, AtCAT1 and AtSOD (Cu/Zn) genes, which are associated with the antioxidant system, were significantly upregulated in TaWRKY1-2D transgenic Arabidopsis plants under drought stress.…”

“…A number of family genes have been shown to participate in the regulation of plant drought resistance through the ROS pathway. For example, the mint McWRKY57 enhances the activities of the antioxidant enzymes catalase, superoxide dismutase and peroxidase in transgenic plants and improves drought tolerance [ 14 ]. Overexpression of TaWRKY1-2D enhanced drought tolerance in transgenic Arabidopsis and TaWRKY1-2 silencing in wheat increases the MDA content and reduces the proline and chlorophyll contents as well as antioxidant enzyme activity [ 15 ].…”

Genome-wide identification and comprehensive analysis of WRKY transcription factor family in safflower during drought stress

“…The expression of the McWRKY57 gene was stimulated by mannitol, ABA, and MeJA. Overexpression of McWRKY57-like in Arabidopsis plants considerably improved plant drought tolerance 57 . Additionally, transgenic Arabidopsis lines overexpressing of EjWRKY17 exhibited increased cotyledon greening and root elongation under abscisic acid (ABA) treatment 58 .…”