Role of WRKY Transcription Factors in Regulation of Abiotic Stress Responses in Cotton

Abstract

Environmental factors are the major constraints in sustainable agriculture. WRKY proteins are a large family of transcription factors (TFs) that regulate various developmental processes and stress responses in plants, including cotton. On the basis of Gossypium raimondii genome sequencing, WRKY TFs have been identified in cotton and characterized for their functions in abiotic stress responses. WRKY members of cotton play a significant role in the regulation of abiotic stresses, i.e., drought, salt, and extreme temperatures. These TFs either activate or repress various signaling pathways such as abscisic acid, jasmonic acid, salicylic acid, mitogen-activated protein kinases (MAPK), and the scavenging of reactive oxygen species. WRKY-associated genes in cotton have been genetically engineered in Arabidopsis, Nicotiana, and Gossypium successfully, which subsequently enhanced tolerance in corresponding plants against abiotic stresses. Although a few review reports are available for WRKY TFs, there is no critical report available on the WRKY TFs of cotton. Hereby, the role of cotton WRKY TFs in environmental stress responses is studied to enhance the understanding of abiotic stress response and further improve in cotton plants.

Genome-wide annotation and expression analysis of WRKY and bHLH transcriptional factor families reveal their involvement under cadmium stress in tomato (Solanum lycopersicum L.)

“…WRKY and bHLH transcription factors play an important role in plants’ heavy metal stress defense ( Guo et al., 2022 ). However, little information is available about the Cd-responsive WRKYs and bHLHs in tomato ( S. lycopersicum ).…”

“…In this regard, the current study has emphasized identifying and characterizing two large and very important families of TFs, i.e., WRKY and bHLH gene families, in tomato plants. The detailed composition and mode of action of both WRKY and bHLH TFs are well-explored ( Heim et al., 2003 ; Chen et al., 2019 ; Hao et al., 2021 ; Wani et al., 2021 ; Guo et al., 2022 ). Here, we will focus on the comparative genomic studies and functional roles of WRKY and bHLH TFs in tomato, particularly in heavy metal defense.…”

“…The WRKY TFs are also called jack-of-all-trades because they regulate many developmental and physiological processes, such as seed dormancy and germination, seed development, root formation, plant growth, senescence, trichome morphogenesis, and response to various biotic and abiotic stress factors ( Ülker and Somssich, 2004 ; Rushton et al., 2010 ; Mao et al., 2011 ; Huang et al., 2012 ; Imran et al., 2019 ; Guo et al., 2022 ). To date, 81 WRKY ( Zhao et al., 2021 ) and 161 bHLH ( Riaño-Pachón et al., 2007 ) TFs have been identified from the entire tomato genome through genome-wide analysis.…”

Physiological and Transcriptional Responses of Apocynum venetum to Salt Stress at the Seed Germination Stage

“…Previous studies have demonstrated that genes related to TFs play critical roles in response to salt stress in other plants. For example, the WRKY TFs of cotton play a significant role in the regulation of abiotic stresses (i.e., salt, drought, and extreme temperatures) [ 91 ]; MYB TFs are involved in the responses to different abiotic stresses, such as salt, cold, and drought, and the FvMYB82 gene probably plays an important role in the response to salt and cold stresses in Arabidopsis thaliana by regulating downstream related genes [ 92 ]; and NAC TFs play vital roles in plant development and responses to various abiotic stresses, and the ThNAC4 gene of Tamarix hispida is involved in salt and osmotic stress tolerance [ 93 ]. In this study, 16 TFs were directly associated with stress response and seed germination.…”

Genome-Wide Identification and Expression Analysis of WRKY Transcription Factors in Siraitia siamensis

“…A typical WRKY motif has therefore been suggested, embracing the consensus sequence W(R/K)(K/R)Y [ 5 ]. According to the number of WRKY domains and the type of zinc-finger motif, WRKY proteins can be divided into three major groups, Group I, Group II, or Group III [ 6 ]. Those in Group I contain two WRKY domains and one C 2 H 2 (C-X 4-5 -C-X 22-23 -H-X 1 -H) zinc finger motif; Group II includes proteins with one WRKY domain and a C 2 H 2 zinc finger motif, and can be further divided in five subgroups (IIa, IIb, IIc, IId and IIe) according to the primary amino acid sequence [ 7 ].…”