Research Progress of WRKY Gene Functions in Horticultural Plants

WRKY transcription factors are a class of trans-acting factors unique to plants. WRKY gene family has many members and is one of the largest families of transcription factors in plants. At present, the WRKY transcription factor family has been genome-wide identified in various horticultural plants. A large number of studies have shown that WRKY transcription factors are involved in various biological processes in plants, such as nutrient deprivation, embryogenesis, seed development, trichome development, leaf senescence, and other developmental and hormonal regulation processes. They are important components of many regulatory signal networks. WRKY transcription factors play an important role in the transcriptional regulation mechanism of plant adaptation to various stress environments. It has been shown to play an important role in biological stress response and participate in plant defense mechanisms. Its important role in the regulation of plant defense against pathogens, viruses and pests is gradually being revealed. In addition, the role of WRKY transcription factors in plant response to environmental abiotic stresses has been continuously analyzed. WRKY transcription factors are involved in regulating plant response to drought, temperature, salt and osmosis, and plays a positive or negative regulatory role in this process. Based on the relevant research results in recent years, the roles and regulatory mechanisms of WRKY transcription factors in the growth and development, stress response and metabolic synthesis of horticultural plants are reviewed in this paper. Meanwhile, the important biological functions of WRKY transcription factors in horticultural plants are further clarified as well. Furthermore, the transcriptional regulation network mediated by WRKY transcription factors is elucidated, which will provide theoretical supports for genetic resources and molecular breeding related to excellent traits of horticultural plants.