Abstract:
WRKY proteins are a group of important transcriptional regulators that are unique to plants. WRKY specifically bind with the W-box
cis-elements in the promoters of downstream genes to induce or inhibit the transcription and expression of related genes, to regulate plant growth and development, as well as responses to biotic and abiotic stresses. The WRKY gene family is large in number, there are 74 identified WRKY genes 74 in
Arabidopsis genome, 182 genes in soybean genome and 109 genes in rice genome, respectively. WRKY genes play pivotal roles in plant response to various biological and abiotic stresses such as drought, salinity, high temperature, nutrient deficiencies, and pathogen infection. Up to now, it has been proved that the
AtWRKY45 and
AtWRKY75 are involved in regulating the responses of
Arabidopsis to low P stress,
GmWRKY142 positively regulates the tolerance of
Arabidopsis to Cd stress. When exposure to stress, the plant WRKY protein specifically binds to the W-box
cis-element in the conserved region of the related gene promoter, thereby achieves self-regulation or cross regulation, then activates or inhibits the transcriptional expression of downstream genes in response to various stress conditions. Numerous downstream target genes have also been revealed consequently, such as the PHT family members related to P nutrition; three
AtWRKY genes and six
GmWRKY genes are involved in regulating plant nitrogen uptake and utilization; six
AtWRKY genes, ten
GmWRKY genes, and five
OsWRKY genes regulate plant response to phosphorus deficiency; two
AtWRKY genes and six
GmWRKY genes affect plant potassium absorption and utilization; three
GmWRKY genes are involved in regulating the absorption and utilization of sulfate; one
AtWRKY gene is involved in regulating the uptake and utilization of boron; one
AtWRKY gene and one
OsWRKY gene are involved in regulating plant iron absorption; seven
AtWRKY genes, one
GmWRKY gene, and one
OsWRKY gene are involved in mitigating cadmium toxicity; two
AtWRKY genes, two
GmWRKY genes, and one
OsWRKY gene participate in helping plants detoxify aluminum toxicity. The foci of future researches are: 1) mining new WRKY transcription factors that regulate nutrient uptake and utilization and the downstream genes; 2) decoding the regulation of nutrient-related WRKYs at the translation and post-translation level; 3) determining the transcription of nutrient-related WRKY at epigenetic level; 4) revealing the proteins that interact with WRKY and the underlying mechanisms under nutrient deficiency.