Search Results (3)

WRKY transcription factors comprise one of the largest gene families and serve as key regulators of plant defenses against herbivore attack. However, studies related to the roles of WRKY genes in response to herbivory are limited in maize. In this study, a total of 128 putative maize WRKY genes (ZmWRKYs) were identified from the new maize genome (v4). These genes were divided into seven subgroups (groups I, IIa–e, and III) based on phylogenomic analysis, with distinct motif compositions in each subgroup. Syntenic analysis revealed that 72 (56.3%) of the genes were derived from either segmental or tandem duplication events (69 and 3, respectively), suggesting a pivotal role of segmental duplication in the expansion of the ZmWRKY family. Importantly, transcriptional regulation prediction showed that six key WRKY genes contribute to four major defense-related pathways: L-phenylalanine biosynthesis II and flavonoid, benzoxazinoid, and jasmonic acid (JA) biosynthesis. These key WRKY genes were strongly induced in commercial maize (Jingke968) infested with the Asian corn borer, Ostrinia furnacalis, for 0, 2, 4, 12 and 24 h in the field, and their expression levels were highly correlated with predicted target genes, suggesting that these genes have important functions in the response to O. furnacalis. Our results provide a comprehensive understanding of the WRKY gene family based on the new assembly of the maize genome and lay the foundation for further studies into functional characteristics of ZmWRKY genes in commercial maize defenses against O. furnacalis in the field. Full article

WRKY transcription factors had multiple functions in plant secondary metabolism, leaf senescence, fruit ripening, adaptation to biotic and abiotic stress, and plant growth and development. However, knowledge of the group III WRKY subfamily in fiber development in upland cotton (Gossypium hirsutum L.) is largely absent. Previous studies have shown that there were 21 putative group III WRKY members in G. hirsutum L. These putative amino acid sequences from the III WRKY group were phylogenetically clustered into three clades. Multiple alignment, conservative motif analysis, and gene structure analysis showed that the members clustered together in the phylogenetic tree had similar motifs and gene structures. Expression pattern analysis revealed that variation in the expression levels of these genes in different tissues and fiber development stages. To better understand the functions of putative group III WRKY genes in G. hirsutum L., we selected the cotton fiber initiation-related gene GhWRKY53 for cloning and functional identification. The subcellular localization experiment of GhWRKY53 in Nicotiana tabacum leaves showed that it was located in the nucleus. The heterologous expression of GhWRKY53 in Arabidopsis thaliana could significantly increase the density of trichomes. Twelve proteins that interacted with GhWRKY53 were screened from the cotton fiber cDNA library by yeast two-hybrid experiment. This study findings lay a foundation for further research on the role of the GhWRKY53 during cotton fiber development and provide a new insight for further studying putative group III WRKY genes in G. hirsutum L. Our research results also provide vital information for the genetic mechanism of high-quality cotton fiber formation and essential genetic resources for cotton fiber quality improvement. Full article

WRKY transcription factors are one of the largest families in plants, playing important roles in regulating plant immunity. Malus sievesii has abundant genetic diversity and can offer various and high-quality gene resources. In this study, 112 putative MsWRKY proteins were identified from a full-length transcriptome of M. sieversii during the Valsa canker disease (caused by Valsa mali). The MsWRKY proteins were phylogenetically divided into three groups (I–III). Motif compositions of the MsWRKY proteins were clustered and fifteen conserved motifs were observed. Expression pattern analysis showed that thirty-four MsWRKY transcripts strongly responded to the V. mali infection, demonstrating that MsWRKY transcripts might play different roles during the response. Functional identifications were subsequently conducted with transient expressions, demonstrating that MsWRKY16, MsWRKY21, MsWRKY70, MsWRKY74 and MsWRKY85 positively regulated the resistant response. Besides, the MsWRKY21, MsWRKY70 and MsWRKY85 were dramatically induced by salicylic acid (SA), methyl-jasmonate acid (MeJA) and 1-aminocyclopropane-1-carboxylate (ACC), indicating that they play important roles in the regulatory resistance of V. mali infection. This work provides a comprehensive understanding of the WRKY family in M. sieversii and will build a foundation for future research of the potential disease resistances MsWRKY transcripts. Full article