The Cotton WRKY Gene GhWRKY41 Positively Regulates Salt and Drought Stress Tolerance in Transgenic Nicotiana benthamiana

Abstract

WRKY transcription factors constitute a very large family of proteins in plants and participate in modulating plant biological processes, such as growth, development and stress responses. However, the exact roles of WRKY proteins are unclear, particularly in non-model plants. In this study, Gossypium hirsutum WRKY41 (GhWRKY41) was isolated and transformed into Nicotiana benthamiana. Our results showed that overexpression of GhWRKY41 enhanced the drought and salt stress tolerance of transgenic Nicotiana benthamiana. The transgenic plants exhibited lower malondialdehyde content and higher antioxidant enzyme activity, and the expression of antioxidant genes was upregulated in transgenic plants exposed to osmotic stress. A β-glucuronidase (GUS) staining assay showed that GhWRKY41 was highly expressed in the stomata when plants were exposed to osmotic stress, and plants overexpressing GhWRKY41 exhibited enhanced stomatal closure when they were exposed to osmotic stress. Taken together, our findings demonstrate that GhWRKY41 may enhance plant tolerance to stress by functioning as a positive regulator of stoma closure and by regulating reactive oxygen species (ROS) scavenging and the expression of antioxidant genes.

A novel cotton WRKY gene, GhWRKY6‐like, improves salt tolerance by activating the ABA signaling pathway and scavenging of reactive oxygen species

“…Transcription factors that function in salt and drought stresses could be used to attain higher yields of plants. Numerous studies revealed that WRKY transcription factors play a significant role in the response to drought and salt stresses (Ma et al , Chu et al , Liu et al ). Therefore, we cloned, characterized and transformed a novel WRKY transcription factor gene, GhWRKY6‐like , to enhance salt, osmotic and drought tolerance.…”

“…Another WRKY gene, TaWRKY19 , was isolated from wheat and overexpressed in Arabidopsis , and these overexpressing transgenic plants conferred tolerance to drought and salt stresses (Niu et al ). In addition to other plants, a few cotton WRKY genes have also been reported as being potential candidates to enhance salt and drought tolerance in plants (Yan et al , Chu et al , Jia et al , Liu et al ). In this study, we characterized a novel WRKY gene, GhWRKY6‐like , that plays a significant role in salt and osmotic stress tolerance in cotton.…”

Insights into Drought Stress Signaling in Plants and the Molecular Genetic Basis of Cotton Drought Tolerance

“…Lower malondialdehyde content, higher antioxidant activity, and induced stomatal conductance [41] GhWRKY17…”

“…Another TF related to R2R3-type MYB, GbMYB5, responded positively to drought stress [40]. Ectopic expression of the GhWRKY41 gene in tobacco plants led to increased activity of antioxidant enzymes, lower MDA content, increased stomatal closure, and upregulation of antioxidant-related genes [41]. In Gossypium barbadense, a R2R3-type GbMYB5 TF gene enhanced drought tolerance in transgenic tobacco and cotton.…”

Understanding the Effect of Structural Diversity in WRKY Transcription Factors on DNA Binding Efficiency through Molecular Dynamics Simulation

“…The WRKY family have been involved in various physiological as well as developmental processes, for instance: seed germination [12], plant growth [13], seed and trichome development [14,15], panicle development [16], secondary metabolism [17], leaf senescence [18], bud and floral differentiation [19], and hormone signaling [20,21]. The WRKY family is also involved in responses to a range of biotic stressors like, drought, salinity [22,23], heat [24], cold [25], and abiotic stressors, such as bacteria [26], nematodes [27], fungi [28], viral pathogen resistance [29].…”